electrical services minimum requirement - NSW Public Works

Part 

ELECTRICAL SERVICES 

MINIMUM REQUIREMENT 

(Referred to as MEW E101) 

∅ General 

1 Installation 

2 Switchboards and Associated Equipment 

3 Accessories 

4 Luminaires - Supply and Installation 

5 Electric Motors 

6 Painting, Colour Coding and Labelling 

September 2007

• CROWN COPYRIGHT: 

DOCUMENT OWNERSHIP 

No part of this work may be reproduced or copied without the written permission of the 

publisher. This document is published by NSW Water Solutions, NSW Department of 

Commerce, 2-24 Rawson Place, Sydney 2000. 

• ACCREDITATION: 

Only design consultants who have attended the NSW Department of Commerce 

Accreditation Course and are accredited by the NSW Department of Commerce for 

MEWE101 usage, are legally permitted to use this document as part of design 

documentation. 

A fee for such usage per project will apply. 

This Accreditation would be reviewed every 3 years or when this document is updated, 

whichever is the earlier. 

Apply to the Senior Electrical Engineer, NSW Department of Commerce, McKell 

Building, 2-24 Rawson Place, Sydney 2000 (Tel 937 28162) for accreditation.

PART Ø - GENERAL 

0.1 SCOPE 

Part 0 - General 

This document covers the minimum requirements for Low Voltage and Extra Low Voltage 

Switchboards and electrical installation for Sewage and Water Supply Schemes. 

Read this document in conjunction with the specification clauses and exhibited drawings 

as well as relevant standards. 

Should a higher or more onerous standard requirement be specified in the Service and 

Installation Rules of New South Wales than is specified in MEW E101 or in the 

specification clauses and/or exhibited drawings, then that higher or more onerous 

standard requirement shall apply. 

Should a higher or more onerous standard/requirement be specified in AS/NZS3000 than 

is specified in MEWE101 or in the specification clauses and/or exhibited drawings, then 

that higher or more onerous standard/requirement shall apply. 

0.2 USER GUIDELINE FOR THE SELECTION OF SWITCHBOARD 

CLASSIFICATION 

Switchboard classifications are defined in this document. 

The correct classification for the electrical installation should be specified in the main 

body of specification clauses or on the exhibited drawings. 

The selection of the correct classification is dependent on a number of criteria such as: 

• Fault level 

• Importance of the installation 

• Standby arrangements 

• Supply Authority requirements 

• Risk and Consequences of a major fault 

• Acceptable time to restore services in the event of a major fault 

• Incidence of lightning 

• Type of equipment installed in the Switchboard. 

Only design consultants who have attended the NSW Department of Commerce 

Accreditation Course and are accredited by the NSW Department of Commerce for MEW 

E101 usage, are legally permitted to use this document. A fee for the use of this 

document per project will apply. 

MEW E101 Page 1


0.3 STANDARDS 

AS 1000 The International system of Units (SI) and its application 

AS 1023 Low Voltage Switchgear and Controlgear - Protection of Electric Motors 

AS 1029 Low Voltage Contractors 

AS 1042 Direct-acting Indicating Electrical Measuring Instruments and their Accessories 

AS 1100 Technical Drawing 

AS 1102 Graphical symbols for Electrotechnology 

AS 1103 Diagrams, Charts and Tables for Electrotechnology 

AS 1110 ISO Metric Hexagon Precision Bolts and Screws 

AS 1111 ISO Metric Hexagon Commercial Bolts and Screws 

AS 1125 Conductors in Insulated Cables and Flexible Cords 

AS 1202 AC Motor Starters (up to and including 1000V) 

AS 1220 Aluminium Conductors Steel Reinforced for Overhead Power Transmission Purposes 

AS 1284 Electricity Metering 

AS 1345 Identification of the contents of piping, conduits and ducts 

AS 1359 Rotating Electrical Machines - General Requirements 

AS 1360 Rotating Electrical Machines of Particular Types or for Particular Applications 

AS 1417 Rules for Antennas for the Reception of Radio and Television Broadcasting for the 

Range 30 to 1000 MHz. 

AS 1431 Low Voltage Switchgear and Controlgear - Control Circuit Devices and Switching 

Elements 

AS 1531 Aluminium Conductors for Overhead Power Transmission Purposes 

AS 1580 Paints and Related Materials - Methods of Test 

AS 1627 Metal Finishing - Preparation and Pre-treatment of Surfaces 

AS 1648 Visually Stress Graded Cypress Pine for Structural Purposes 

AS 1650 Hot-dipped Galvanised Coatings on Ferrous Articles 

AS 1675 Current Transformers - Measurement and Protection 

AS 1746 Hard-drawn Copper Conductors for Overhead Power Transmission Purposes 

AS 1882 Earth and Bonding Clamps 

AS 1930 Circuit Breakers for distribution Circuits (Up to and including 1000 V ac and 1200 V ac) 

AS 1939 Degrees of Protection Provided by Enclosures for Electrical Equipment 

AS 2005 Low Voltage Fuses - Fuses with Enclosed Fuse-Links 

AS 2052 Metallic Conduits 

AS 2053 Non-metallic Conduits and Fittings 

AS 2184 Low Voltage Switchgear and Controlgear - Moulded Case Circuit-Breakers for Rated 

Voltages (up to and including 600 V ac and 250 V dc) 

AS 2648 Underground Marking Tape - Part 1 - Non-detectable Tape 

AS 2700 Colour Standards for General Purposes 

AS 2768 Electrical Insulating Materials - Evaluation and Classification 

AS 3000 SAA Wiring Rules 

AS 3008 Electrical Installations - Selection of Cables 

Part 1 - Cables for alternating voltages up to and including 0.6/1 kV 

AS 3012 Electrical Installations - Construction and Demolition sites 

AS 3013 Electrical Installations - Wiring Systems for Specific Applications 

AS 3100 Approval and Test Specification - General Requirements for Electrical Equipment 

AS 3111 Approval and Test Specification for Miniature Overcurrent Circuit-Breakers 

AS 3112 Approval and Test Specification - Plugs and Socket-outlets 

AS 3117 Approval and Test Specification - Bayonet Lamp holders 

AS 3126 Approved and Test Specification - Extra Low Voltage Transformers 

AS 3131 Approval and Test Specification - Plugs and Socket-outlets for Use in Installation Wiring 

Systems 

AS 3133 Approval and Test Specification - Air Break Switches 

AS 3137 Approval and Test Specification - Luminaires (Lighting Fittings) 

AS 3140 Approval and Test Specification - Edison Type Screw Lamp holders 

AS 3147 Approval and Test Specification - Electric Cables - Thermoplastic 

AS 3190 Approval and Test Specification - Residual Current D (current operated earth leakage 

devices) 

AS 3191 Approval and Test Specification for Electrical Flexible Cords 

Page 2 MEW E101


AS 3300 Approval and Test Specification - General Requirements for Household and Similar 

Electrical Appliances 

AS 3439.1 Low Voltage Switchgear and Controlgear Assemblies 

:2002 

AS 3760 In-service Safety Inspection and Testing of Electrical Equipment 

AS 3766 Mechanical Fittings for Low Voltage Aerial Bundled Cables 

AS 3947.3 Air Break Switches, Isolators and Fuse Combination Units (1000v AC and 1200 V dc) 

IEC 96-3 Radio-frequency cables 

Part 3 - General requirements and tests for single-unit coaxial cables for use in cable 

distribution systems 

Service and Installation Rules of NSW, October 2006 (issued by the Department of 

Energy, Utilities and Sustainability) 

HB 243 Australian Regulatory Arrangement Handbook 

HB 29 Communication Cabling Handbook 

NOHSC: National Standard for Manual Handling 

1001 

Occupational Health and Safety Regulation 2001 

Carry out all work in accordance with the above standards. 

The latest editions of the above are to be used unless otherwise specified. Where a 

standard has been superseded, the latest standard shall be used. 

MEW E101 Page 3


0.4 ABBREVIATIONS 

Abbreviations where occurring in this Section of the Specification are in general to 

AS 1100. 

Metric units have been abbreviated in accordance with AS 1000. 

Where other abbreviations and expressions occur in the Specification, they shall mean 

as follows:- 

ACMA Australian Communication and Media Authority 

AS Australian Standard 

BS British Standard 

BWL Bottom Water Level 

BFL Bottom Flood Level 

C/O Change Over 

CFS Combination Fuse Switch Unit 

ELV Extra Low Voltage 

FCU Fuse Combination Unit (i.e. a combination switch fuse or combination 

fuse switch) 

FL Full Load 

FLC Full Load Current 

HD-UPVC Heavy Duty Unplasticised PVC 

HDHC Hard Drawn High Conductivity (Copper) 

I/O Input/Output 

IP Rating Degree of Protection as described in AS 1939 

LD-UPVC Light Duty Unplasticised PVC 

LED Light emitting diode 

MCC Motor Control Centre 

MEN Multiple Earthed Neutral (System) 

MEPS Minimum Energy Performance Standard 

MIMS Mineral Insulated Metal Sheathed (Cable) 

MWL Maximum Water Level 

N/C Normally Closed 

N/O Normally Open 

NAASRA National Association of Australian State Roads Authorities 

PA Public Address (System) 

PAX Private Automatic Exchange (Telephone) 

pf Power Factor 

PLC Programmable Logic Controller 

PLYSWS Paper Insulated Lead Alloy Sheathed Steel Wire Armoured and Served 

(Cable) 

PVC Polyvinylchloride 

RSS Rolled Steel Section 

SAA Standards Association of Australia 

SCA Switchgear and Controlgear Assembly 

SPO Special Purpose Outlet 

TPI Thermoplastic Insulated (Cable) 

TPS Thermoplastic Insulated and Sheathed (Cable) 

TWL Top Water Level 

TFL Top Flood Level 

UPVC Unplasticised Polyvinylchloride 

XLPE Cross Linked Polyethylene 

Page 4 MEW E101

PART 1 - INSTALLATION 

101 SETTING OUT OF RUNS 

Apply the following minimum requirements when setting out the work: 

Part 1 -Installation 

(a) Fix cables and conduits parallel to building members, walls, doors, etc. and run on 

the square wherever possible. In slabs, conduits may be run diagonally. 

(b) Unless otherwise indicated, cable from below any circuit supplying floor mounted 

equipment. Conduits shall not be surface mounted on floors. They shall instead be 

sunk or concealed under floor boards or in concrete floor slabs. 

(c) Run in separate conduits circuits originating at different switchboards. 

(d) Locate cables and conduits run in roof spaces below the roof heat insulation and 

sarking and run above the insulation, or if insulation is not installed, derate the 

cables in accordance with AS 3008.1 for an assumed ambient temperature of 

55 o C. 

(e) Protect surface or recessed wiring in TPS cables to switches, outlets and similar 

terminations by conduit drops sized to accept the TPS cables and originating at an 

accessible point in the roof space. 

(f) Arrange all cables and conduits to run parallel to floors and building members. 

(g) Install TPS cabling so that it may be fully replaced. Where TPS cabling passes 

through an inaccessible space it shall be capable of being drawn through the 

space such that rewiring can be readily performed. 

Note: This may require the installation of conduit through the space. 

(h) Install site reticulation cables in underground conduits unless stated otherwise. 

Direct buried cables are not permitted. Lay underground pipes straight with 

minimum deviation from the horizontal and vertical planes but graded for drainage. 

TPI cables are not permitted underground. 

(i) No conduits allowed in the floor slab of boiler rooms. 

102 PENETRATIONS 

102.1 Generally 

Use mortar of a 3 : 1 sand cement mix with surfaces "Bondcreted" prior to applying the 

mortar for repairs to all penetrations and repairs. 

No penetrations through damp courses are permitted. 

102.2 Penetrations Through Waterproof Membranes 

Pipes which enter a building at ground level shall run under the waterproof membrane 

and vertically penetrate the membrane and the concrete slab at the appropriate position. 

Where pipes pass through roofs, proprietary sealing shall be provided between the pipes 

and the waterproof membrane. 

102.3 Penetrations Through External or Existing Structures 

Where pipes pass through external walls, existing ground floor slabs or existing ground 

floor beams, a penetration 10 greater than the pipe diameter shall be provided. The 

penetration space around the pipe shall be made waterproof by using a proprietary 

sealing method. 

MEW E101 Page 5

Part 1 - Installation 

102.4 Unenclosed Cables Passing Through Slabs 

Unenclosed cables in slabs are not permitted. 

103 AERIAL RETICULATION (POWER) 

103.1 Attachment to Poles 

Attach aerial conductors to poles by: 

(a) Pin insulators mounted on a horizontal crossarm provided that the conductors do 

not change direction by more than 10 degrees, or 

(b) Shackle insulators secured by hooks on poles and bolts on crossarms at tee-offs, 

terminations, and other locations. These shackle insulators shall be fixed with 

galvanised nuts and bolts. 

(c) Where aerial bundled conductors are used, terminate in accordance with AS 3766. 

Conductors shall be fastened to pin insulators with tie-wire of 2.5mm² stranded black 

insulated building wire or a suitable proprietary fixing method. 

103.2 Attachment to Buildings 

103.3 Poles 

103.3.1 Generally 

Attach aerial conductors to buildings with shackle insulators and the shackle support shall 

be bolted to masonry or a structural member. Pass the conductor through or around the 

insulator and then around itself. Alternatively, a proprietary fixing method may be used. 

Conductors shall enter the building via a conduit sloping upwards into the building at a 

minimum angle of 45 degrees to the horizontal for weatherproofing. 

Where upstands are required, they shall be of a proprietary manufacture acceptable to 

the Supply Authority for service attachments. 

Unless otherwise indicated, poles shall be hardwood. 

Provide where required by the Supply Authority, a weatherproof box and/or service fuses. 

Protect cables and conduits running down the exterior of a pole to a height of 2000 above 

ground by a galvanised water pipe for conduits under ∅40 or a 3.2mm thick hot dipped 

galvanised channel fixed to the pole for all other conduit sizes. Extend the protection 150 

below the surface. 

Bury, unless otherwise indicated, poles to a minimum depth of 1600. 

Baulk and stay to prevent leaning or bending where poles will be subject to bending 

stresses, e.g. where the aerial cables change direction or terminate. 

103.3.2 Hardwood Poles 

103.3.3 Crossarms 

Provide only dressed, natural round poles with all sapwood removed treated against 

fungus and termites as described in the Wiring Rules to 600 above ground level. 

An alternative fungus treatment may be used only with the approval of the Supply 

Authority and the Superintendent. This alternative treatment requires that the soil around 

and beneath the pole be treated with creosote during the ramming and setting process. 

The pole shall be liberally coated with creosote from the base to 600 above ground level. 

Fit all poles with a galvanised steel domed cap extending 25 down the sides and fastened 

at the side with galvanised steel nails. 

Page 6 MEW E101

Supply crossarms 75 x 75 x 1500 (minimum) finished size hardwood. 


Notch all hardwood poles to accept the crossarms, and securely bolted to the pole using 

M20 galvanised bolts, nuts and washers. 

Brace each crossarm with two braces each 5 x 40 x 690 galvanised steel fixed at 45 

degrees to the pole below the crossarm with an M12 x 75 galvanised coach screw in the 

pole and with M12 galvanised bolts, nuts and washers in the crossarms. 

103.3.4 Service Poles 

Generally service poles shall be hardwood complying with the above requirements; 

however, approved aluminium, steel or concrete poles will be accepted. 

Hot dipped galvanised steel poles after fabrication, cap to prevent moisture entry and set 

in concrete or fixed by means of a galvanised rag bolt assembly. 

Detail proposed poles other than hardwood in the submitted drawings and must have the 

prior written approval of the Supply Authority. 

Drawings must clearly indicate the installation method, particularly the running of cables 

in or on the pole. 

103.4 Aerial Cables 

For details of aerial cables, refer to Clause 106.8. 

104. UNDERGROUND RETICULATION 

104.1 Trenching, Backfilling and Reinstatement 


104.1.2 Inspection 

The work associated with trenching includes clearing, grubbing, excavation, filling and 

consolidation of the trench and all necessary pumping, drainage, shoring and bracing. 

Excavate all trenching included in the works to an even surface free from sharp 

projections. 

Where crossing or running parallel to other services, underground cabling shall be 

spaced as approved. Comply with the requirements of the telecommunication authority, 

gas, water and sewerage authorities. 

Refer to Clause 109 for telecommunication authority requirements. 

Cut existing concrete or bitumen surfaces to be disturbed in a straight line with a masonry 

saw to 75 minimum depth before excavation is commenced. 

Where solid rock is encountered, cables may be chased into rock if approved. 

Enclose direct buried cables that pass under buildings in heavy duty non-metallic 

conduits of adequate size complying the AS 2053. Seal all pipes from pits to items of 

equipment in the pit using expanding foam. 

Minimum conduit depth 600mm to top of conduit. 

Leave all cable trenches ready for inspection at the following stages: 

(i) after laying conduit, but before any backfilling or laying marker tape, and 

(ii) after laying marker tape. 

The entire underground reticulation system shall be inspected prior to cable installation. 

At this time the drainage system will be checked using water inserted at various points 

and the system must drain free of water within two (2) hours. 

MEW E101 Page 7


Notify the Superintendent of required inspections two (2) working days prior to the 

inspection. 

104.1.3 Backfilling and Reinstatement 

Bed PVC conduits on 50 minimum of clean sand and cover by a further 50 of clean sand 

before backfilling the trench. 

After laying the conduits in unpaved areas, backfill the trench and consolidate to about 10 

above the natural ground level. Remove all excess spoil from the site. 

Existing grassed areas shall be backfilled and turf re-laid on prepared bed or otherwise 

re-grassed to 10 above natural ground level. 

In existing concrete or brick paved areas, backfill the trench with clean sand to the 

underside of the reinstated pavement and consolidated by watering and mechanical 

compaction. Reinstate surfaces to the original level. For concrete surfaces use 

approved reinforced steel, keyed to the existing to prevent the reinstalled concrete from 

subsiding and cracking. 

In existing bitumen paved areas, camber the reinstated surfaces so that the edges are 

flush and the centre is 10 above the existing pavement. The top 150 (minimum) 

immediately below the bitumen, shall consist of finely crushed gravel mechanically 

compacted into the trench. Prime the existing bitumen edges of the trench shall be prime 

coated with bitumen prior to laying 75 minimum of hot "pre-mix" bitumen to the finished 

cambered surface. If it can be shown that hot pre-mix is not available, cold pre-mix will 

be accepted. 

104.2 Underground Cable Protection 

To preclude damage, cables installed in pipes shall be drawn using rollers, drumjacks 

and a cable stocking of the correct size. 

A 150 wide orange marker tape bearing the words "WARNING - ELECTRIC CABLE 

BURIED BELOW" or similar and manufactured in accordance with AS 1648, Part 1, shall 

be laid in the trench 150 below ground level for the entire length of all underground cable 

and conduit runs. 

Marker tape is also to be provided over conduits and pipes installed underground for 

future use. 

104.3 Underground Cable Draw-In Pits 

Provide draw-in pits for underground cables as indicated. Where the size of the pit is 

indicated, the dimensions refer to inside dimensions. The pits walls and bottoms to be 

minimum 100 reinforced concrete. The concrete shall contain an approved additive to 

prevent ingress of water. 

Alternatively proprietary type glass reinforced moulded cement pits or "Polycrete" with 

minimum 10 thick walls and bottom may be used and installed in accordance with the 

manufacturer's instructions on a minimum 100 thick gravel aggregate bed which shall 

extend under the entire pit bottom. Encase the pit in a 100 thick reinforced concrete 

surround with the top neatly finished. 

Drain all pits. The minimum drainage requirement is a 300 x 100 deep rubble drain 

graded away from the pit for a distance of 2000. 

Pits greater than 400 wide shall be fitted with covers and frames of cast iron or aluminium 

and concrete. The covers shall maintain a stabilising fit with the frame by a taper contact 

on the sides. All vertical mating surfaces to be fitted to a maximum clearance of 0.25 

mm. 

Covers and frames shall be suitable for the particular loading conditions. Ensure, unless 

shown otherwise, the loadings are low speed, heavy vehicle loads. The maximum mass 

of any individual section of the cover shall not exceed 40 kg. 

Fit pits 400 wide and less with proprietary concrete covers. 

Page 8 MEW E101


Install all pits with the top of the cover 25 above the surrounding finished level and grade 

the surface for 500 around the pit. 

Provide one set of lifting handles for the covers and store on site as directed. 

Where the size of the pit is not indicated, minimum dimensions are 600 x 600 x 900 

deep. 

The word "ELECTRIC" in 25 high letters shall be moulded into the lids of all such pits 

which contain electric power cables. 

Pits used for the purpose of the telecommunications authority’s telephone services shall 

bear the marking “Telecommunication” as required by the ACMA standard. 

Also see Clause 108.9 for draw-in box details. 

105 MARKING PLATES FOR UNDERGROUND RETICULATION 


Install marking plates on all underground cable or conduit runs. Manufacture plates from 

minimum 1mm thick brass or other approved material 75 x 75 and fix with approved 

waterproof adhesive and four brass or stainless steel screws to suit the material of the 

marking plates. Use stainless steel plates and screws at sewage treatment works and 

sewage pumping stations. 

Do not install marking plates on cable pit lids but may be installed on the concrete lip of a 

cable pit. 

Engrave marking with minimum 4 mm high lettering. 

Install marking plates flush with the finished ground level. Recess or bevel marking 

plates in paved areas. 

Prepare accurate record scale drawings of proposed marker locations and underground 

reticulation prior to backfilling and will be retained by the Superintendent until markers are 

installed. 

105.2 Indication of Cable Entry to Buildings 

Where underground cables enter a building fix a marking plate to the wall at a height of 

300. Engrave the plate with an arrow pointing downwards and the words "ELECTRIC 

CABLE". 

In addition, fix a marking plate to concrete paving or the top face of a concrete block 

approximately 150 x 150 x 300 deep located immediately above the cable and as close 

as practical to the building. Engrave the plate with an arrow, pointing in the direction in 

which the cable is laid, and the words "ELECTRIC CABLE". The distance to the next 

marker, in metres is required. 

105.3 Indication of Directional Changes 

Where an underground cable changes direction, fix two marking plates or alternatively a 

plate with two arrows to a concrete block approximately 200 x 200 x 300 deep located 

immediately above the cable. Engrave each plate with an arrow pointing in the direction in 

which the cable is laid and the words "ELECTRIC CABLE". Neatly stamp the distance to 

the next marker, in metres, into the face of the plate. 

MEW E101 Page 9


105.4 Indication of Cables Under Roads and Paths 

Where a cable passes under a road or path, place a marking plate at each side of the 

road or path. Engrave the marking plate as detailed in Clause 105.3 and fixed to a 

concrete block approximately 150 x 150 x 300 deep. 

Alternatively, marking plates may be fixed to the kerb of a kerbed road. 

105.5 Indication of Terminated Conduits 

Where conduits are terminated underground and beyond the perimeter of a building or 

paved area, fix a marking plate to a concrete block approximately 150 x 150 x 300 deep 

located above the termination point. Engrave the plate with the words "ELECTRIC 

CONDUIT TERMINATED UNDER". 

106 CABLES AND WIRING 


Supply cables, terminations, fittings and accessories suitable for the voltage, current, 

frequency, temperature and environmental duty. 

Terminate copper conductors either into tunnel type connectors or by suitably sized lugs 

sweated or crimped in an approved manner. 

Ross Courtney (solderless) terminations may be used on conductors up to 4mm 2. 

No joints in cables can be made between equipment terminal connections unless 

required by AS 3000. 

Stranded conductors are required above 1mm². 

Cable colours and codes are as follows: 

red, white, blue - active conductors in multi-phase mains and circuits. 

red - active conductors in single phase mains and circuits. 

black - neutral conductor. 

white (numbered cores) - control circuit cabling outside of switchboards. 

green-yellow - earth wires. 

Refer to Clause 205.2 for Cable Identification. 

Carry insulation resistance testing out with a minimum 1000 V DC testing instrument. 

Make final connections to equipment generally using flexible conduit, seal the flexible 

conduit at each end using expanding foam or a cable gland. 

All cables to be PVC insulated PVC sheathed circular unless otherwise specified. 

106.2 Consumer's Mains and Metering 

Run the consumer's mains underground from the Point of Attachment as sheathed 

copper cable in conduit for its entire length to the main switchboard (in the case of current 

transformer metering) or the Supply Authority metering panel (in the case of Direct 

Metering). 

The minimum size of consumers mains is 16mm², however the following requirements 

apply:- 

(a) Current carrying capacity to suit the maximum demand and any stated future 

extensions with an excess current carrying capacity of 30% minimum. 

(b) Be sized so the voltage drop is less than 1.5% at plant future maximum demand at 

(a) above. 

(c) Be either single core PVC/PVC cables or four core PVC/PVC cable XLPE 

insulation may be used. 

Page 10 MEW E101

(d) Comply with the requirements of the Supply Authority. 


Where direct metering is employed the cable between the meter panel and the Main 

Switchboard shall be the same size as the consumers mains and the voltage drop above 

shall include the voltage drop in this cable. Where required by the Supply Authority the 

cable shall be protected by a circuit breaker of the same type and frame size as the Main 

Switchboard Main Switch. 

Install a metering enclosure generally on an exterior wall of the building so that it is 

accessible without entering the building. The panel shall generally be reused. Surface 

mounting on existing buildings is acceptable. The metering enclosure and panel shall be 

Energy Authority approved and suitable for the installation of the metering equipment 

required by the Supply Authority. 

All metering equipment shall be supplied and installed under this Contract including:- 

(a) Plug-in meter bases (if required) 

(b) Service fuses 

(c) Current transformer metering equipment 

(d) All necessary wiring 

(e) Active link (if required) 

(f) Neutral link 

(g) Earth link 

(h) Other equipment required by Supply Authority. 

Paint meter boxes using acrylic gloss in a colour to match the surrounding building. 

106.3 Final Sub-Circuit Wiring 


The minimum size conductors shall be as follows: 

Power Circuits 2.5mm², copper conductors 

Lighting Circuits 1.5mm², copper conductors 

Clock Circuits 1.5mm², copper conductors 

Control Circuits 1.5mm², copper conductors 

Ceiling Fan Circuits 1.5mm², copper conductors 

Final sub-circuit wires shall generally be terminated in tunnel type connectors. Where 

stud or pillar connections are made, stranded conductors shall be prevented from 

spreading; twisting multi-stranded conductors is not considered adequate. 

Connection of single strand conductors to tunnel terminals on moulded case circuit 

breakers shall be made by doubling the conductor back in "open loop" form. 

Wiring shall be carried out using the "draw-in, loop-in" system for both TP1 and TPS 

cables. No intermediate connections to be made except for TPS cables where looping 

terminals may be used at switches, light fittings etc. 

Final connections to equipment having parts of the surface at a temperature greater than 

the temperature rating of the circuit cable shall be made with cable having insulation at 

least rated to 200 degrees Celsius maximum operating temperature. 

Supply all motors with a local rotary isolator connected in the control circuit adjacent to 

the motor. Make final connections to all equipment using flexible conduit. 

106.4 Instrumentation Cables 

Instrumentation cables shall be cables that: 

MEW E101 Page 11


i. Carry ELV analogue signals e.g. 4-20 mA dc. 

ii. Connect to instruments for the purpose of signalling or monitoring. 

iii. Connect to the inputs of PLC's or alarm annunciators. 

Cables shall be min. 0.5mm² PVC insulated aluminium polyester screened PVC 

sheathed. 

A separate 2 core cable shall be supplied for each analogue signal (equal to Dekron 

IEB183 type). 

Digital signals may use a multi, twisted pair overall screened PVC cable. Each digital 

signal shall have its own pair as, common returns are not permitted. Cable shall be 

equal to Dekron IEC183 type. 

The screen of each cable shall be earthed at the switchboard only. 

106.5 Insulated Non-Armoured Cables in Enclosures (TPI) 

Cables shall be 0.6/1 kV grade with minimum V75 or XLPE insulation. 

106.6 Underground Grade Insulated and Sheathed Non-Armoured Cables (TPS) 

Cables shall be 0.6/1 kV grade with minimum V75 or XLPE insulation. 

The cables shall have the manufacturer's name and reference and the word 

"UNDERGROUND" clearly indented in the sheathing. 

106.7 Armoured and Sheathed Cables (Other than Paper Insulated) 

Cables shall be 0.6/1 kV grade with minimum V75 or XLPE insulation and shall have 

armouring of galvanised steel wire (double or single), steel tapes, or aluminium strip/wire. 

Tape armouring shall not be used to support the cables during installation. 

Armouring shall be cleaned, clamped and connected to earth at the origin of the cable. It 

shall not be used as an earth conductor. 

106.8 Aerial Cables 

Cables shall comply with AS 1746 "Hard-Drawn Copper conductors for Overhead Power 

Transmission Purposes" or AS 3607 "Bare Overhead Aluminium Conductors Steel 

Reinforced", or AS 1531 "Aluminium Conductors for Overhead Power Transmission 

Purposes". 

Aerial cables attached to buildings shall be insulated. Connections between aluminium 

able and copper aerial cable shall be made with a bail clamp having aluminium and 

tinned copper connectors. 

Where aluminium cables are terminated to copper cables the aluminium cable shall be 

physically above the copper cable. 

106.9 Special Purpose 

106.9.1 Essential Service Cables 

Unless other indicated, cables supplying power to designated "Essential Services" shall 

consist of MIMS copper conductor copper sheath cables. 

Where run horizontally, the cable shall be as high as possible, separately fixed directly to 

the building structure (eg underside of slab). Where run vertically, the cables shall be 

mechanically protected. Where a number of services cross or follow a similar route the 

"Essential Services" cable shall be located at the highest point and closest to the 

structural support. 

Metal cable fixings shall be used; the use of nylon or plastic material is prohibited. 

106.9.2 Telephone Cables 

Page 12 MEW E101


Cables used for communication purposes (Telephone, Intercom etc) shall be multi-pair 

telephone cables of nominal conductor diameter 0.5mm minimum to ACMA Specification. 

Cables installed within buildings shall be PVC insulated and sheathed. Cables installed 

external to a building shall be Polythene insulated and sheathed. 

All work associated with telephone line connections shall comply with the following: 

106.9.3 Fire Alarm Cables 

• Australian Regulatory Arrangement Handbook HB 243-2007 (Communication 

Cabling Manual Module 1) 

• Communication Cabling Handbook HB29-2007 (Communication Cabling Module 

2) 

• Requirements for Customer Cabling Products (AS/ ACIF S008-2006) 

• Installation Requirements for Customer Cabling (AS/ACIF S009-2006) 

Cables used for the connection of thermal, smoke and manual fire detectors, or other 

associated equipment within the building shall be TPI or TPS minimum 1.5mm 2 stranded 

copper cable. TPS cable shall have red coloured sheathing. 

106.9.4 Security Cables 

Cables used for window and door seals, and associated equipment shall be minimum 

0.5mm ² stranded copper TPI cable, figure 8 configuration. 

Cables for space detectors (ultrasonic, infra-red, microwave, etc) shall be minimum 

0.5mm ² stranded copper TPI, shielded twisted pairs or as per the manufacturer's 

installation requirements. 

106.10 Control Cabling 

(a) General 

The insulation of each cores shall indelibly be numbered consecutively (e.g. one 1) for 

each core. 

(b) 240 Volt a.c. Control Cabling 

Control cables shall be PVC insulated PVC Sheathed cables with copper conductor 

minimum 1.5mm². 

(c) ELV Control Cabling for Connection to Digital I/O 

ELV control cables external to the switchboard connecting to digital I/O shall be V- 

90HTPVC insulated with overall screen and drain wire of minimum size 0.5 mm². 

(d) ELV Control Cabling for Connection to Analogue I/O 

ELV control cables external to the switchboard connecting to analogue I/O shall be 

overall screened, PVC sheathed twisted pair cabling with a minimum conductor size of 

1.5 mm². 

107 EARTHING 


The earthing system shall comply with the Statutory and/or Supply Authority 

requirements. 

Generally earthwires shall be enclosed in conduits with submains and subcircuits. 

A separate MEN system for each building shall be used except where an earthing 

conductor is indicated to be run with the submain to that building. 

MEW E101 Page 13


Metallic pipes used for other services, such as gas, water, sprinkler systems, etc., shall 

be considered as unavoidably in contact with metallic enclosures of electrical equipment 

and shall be effectively bonded to the earthing system. 

107.2 Earthing Conductors for Underground Cables 

Earthing conductors other than the copper sheathing of MIMS cables shall be copper 

stranded conductors sized as per AS 3000, protected by a green-yellow insulation and 

installed as follows: 

(a) Separate earthing conductors for TPI conductors in conduit. 

(c) Separate earthing conductors attached to the cable at 1000 intervals. 

(c) Earthing conductors laid up with the cable. 

107.3 Earth Electrodes 

Earth electrodes shall consist of copper, stainless steel or copper sheathed rods not less 

than 16 diameter driven to a depth of not less than 2400 to reach the permanent moisture 

level. Unless disallowed by the Supply Authority, the indicated footing in each building 

shall be used as an electrode in addition to the above. The earthing conductor shall be 

connected to the reinforcing steel of the indicated footing and the driven electrode. Each 

electrode shall generally be installed in an earthing pit similar to "Polycrete" PEP 22. 

Each pit shall have a reinforced concrete surround minimum 250 wide and 200 deep 

complete with cable markers. 

108 CONDUITS, FITTINGS AND JOINTS 


Conduits and fittings shall comply with either AS 2052 "Metallic conduits and fittings" or 

AS 2053 "Non Metallic conduits and fittings". Conduits smaller than 20 dia. shall not be 

used except for fire alarm systems where 16 dia. will be accepted. 

Conduits shall be in long lengths, straight, smooth and free from rags, burrs and sharp 

edges. Off cuts shall not be used to fabricate long lengths of conduit. Conduits shall be 

set wherever possible to minimise the number of joints. 

Bends shall be of large radius and shall be formed with approved formers. Correctly 

sized springs shall be used to form bends in UPVC conduits. Conduits manipulated or 

bent must maintain true effective diameter and shape at all parts of the bend. Conduit 

sets distorted or showing evidence of kinks, wrinkles, flats or having been heated will not 

be accepted. Wherever possible, UPVC Conduits bends should be preformed by the 

manufacturer. 

Conduits shall be colour coded in accordance with Clause 602 of MEW E101. 

Saddles supporting conduits shall be effectively secured to the surface on which they run. 

Saddles shall be a proprietary brand installed as supplied. 

Conduit systems, including conduits and pipes used to convey cables into buildings, shall 

be sealed to prevent water entry. 

The number of cables including earth wires that may be enclosed in any one conduit or 

pipe shall not exceed that recommended as a guide in AS 3000. 

All conduits exposed to weather shall be painted with a light coloured paint designed for 

the purpose. 

108.2 Heavy Duty UPVC Conduits to AS 2053 (HD-UPVC) 

This conduit shall be coloured "light orange" except for conduits enclosing 

telecommunication authority cables which shall be "white", and may be used 

underground, above ground is permitted only as specified. All fittings shall be of the 

same material as the conduit and all joints shall be made with an approved adhesive 

Page 14 MEW E101


cement of contrasting colour. These conduits are not generally permitted above ground 

except to sizes above ∅63 when the conduit must be painted with a light coloured acrylic 

gloss paint designed for the purpose. 

108.3 Steel Conduits 

All steel conduits shall be heavy protected (hot dipped galvanised), with screw joints and 

screwed terminations, to AS 2052. End joints and terminations shall be made by 

screwing the conduit into the fitting with circular galvanised plated lock nuts screwed onto 

the conduit. 

Steel conduits shall have screwed ends and screwed joints, all threads being painted with 

aluminium paint. Steel conduits shall be electrically and mechanically continuous. 

Electrical continuity tests shall be carried out prior to the installation of draw cords. 

108.4 Light Duty UPVC Conduits to AS 2053 (LD-UPVC) 

This conduit may only be used above ground in positions not exposed to mechanical 

damage. 

All associated plastic fittings shall be of the same material as for the conduits. 

All conduits, plastic fittings and adhesive cement shall be procured from the same 

manufacturer, and the manufacturer's recommended procedures shall be adopted for the 

making of joints. All joints and conduit entries shall be made with an approved adhesive 

cement of a contrasting colour. 

All wall and junction boxes shall be of the same material as the conduits. Where special 

size boxes are indicated but are not obtainable in PVC, pre-fabricated metal boxes shall 

be used where approved. UPVC conduits shall be fixed to such metal boxes with 

screwed PVC adaptors and lock nuts. metal boxes shall be earthed. 

UPVC conduit shall be fixed to a PVC wall box with a screwed PVC adaptor and circular 

lock nuts, unless the conduit enters the wall box via a moulded conduit entry. 

108.5 Flexible Conduits 

Flexible conduits shall be of the plastic sheath, smooth, PVC spiral reinforced type and 

shall be oil resistant, UV resistant and impact resistant. 

Flexible conduits shall be equivalent to: 

i. FLEXICON LPC 

108.6 Installation 


ii. RHINOFLEX by ADAPTAFLEX 

Where the connection is the final connection to an electrical item, the conduit length shall 

be sufficient to allow decoupling and moving aside of the equipment without 

disconnection of the cables or conduit. The degree of protection of fittings associated with 

the conduit shall be IP67. All fittings shall be nickel plated brass except where otherwise 

indicated. Notwithstanding the previous sentence, the fittings shall be compatible with 

chemicals in the area of installation. 

Corrugated flexible conduits are not permitted. 

Carry out all final connections to equipment using flexible conduit. 

Fix flexible conduits to a surface with saddles or stainless steel bands. Do not use PVC 

cable ties for the fixing of flexible conduits. 

Generally, UPVC conduit shall not be installed on exterior surfaces. However, sunlight 

resistant UPVC conduit and fittings complying with AS 2053 and marked with the letter 

"T" may be run in locations exposed to direct sunlight. In sewage treatment works all 

external conduits below 40mm shall be "Clipsal HFT". Also, short runs of HD-UPVC 

MEW E101 Page 15


pipes from underground submains may be surface run where they enter a building if it is 

not practicable to conceal them, provided that they are suitably protected from 

mechanical damage and sunlight. 

All UPVC conduits shall be terminated into metal boxes and enclosures (draw-in-boxes, 

joint boxes, switchboards, ducting etc.) via a screwed PVC adaptor with lock nut. 

Conduits shall be so installed that wiring is carried out using the "draw-in, loop-in" system. 

The conduit run shall be completely installed before wiring is drawn in. 

The wiring shall be drawn in only at outlets and switchboards and, if approved, at draw-in 

boxes. Inspection fittings are allowed only if approved. 

Conduits shall be run directly from the entry point to the termination point with the 

minimum number of sets (the number of sets shall not be greater than the equivalent of 3 

x 90 degree bends). The installation of elbows, tees, etc., is prohibited on conduits 

installed in inaccessible locations. 

All conduits shall be effectively capped during construction. 

Conduits shall be securely fixed to building members and shall be adequately supported 

during all stages of building construction. (Particular care shall be taken to support PVC 

conduit upstands). Generally all conduits shall be concealed and only exposed to view 

when approved. 

Surface conduits shall be made to harmonise as far as practicable with the architectural 

features of the building. Surface conduits shall be run in vertical and horizontal directions 

except where it is desirable to follow the line of a building, where the approval of the 

Superintendent shall be obtained. 

Conduits shall terminate in luminaires, equipment, accessories or in wall boxes and 

junction boxes of a type compatible with the installation. 

Do not exceed the following space factors:- 

1 cable in the conduit - 50% of the area 

2 cables in the conduit - 30% of the area 

3 or more cables in conduit - 40% of the area 

108.6.2 Conduit Saddles 

Conduit saddles shall be either PVC or stainless steel. PVC saddles may be used 

indoors and in wet wells or areas not exposed to sunlight. All other situations shall be 

stainless steel saddles. 

108.6.3 Expansion Joints 

Expansion fittings shall be installed on all straight runs of UPVC plastic conduit, except 

those embedded in concrete or wall chases. The spacing of expansion fittings shall not 

be greater than 8000. A sample of the type of expansion fitting to be used shall be 

submitted prior to installation. Conduit clips shall be installed close to expansion fittings; 

all clips shall be installed to allow the conduit to move freely while expanding or 

contracting. 

Expansion couplings shall be installed wherever expansion or contraction joints occur in a 

building slab. Note: "Bellows" type expansion couplings shall not be used in floor slabs or 

similar installations. 

Each expansion coupling in a building slab shall consist of a short length of flexible 

conduit, to join the two UPVC conduits across the expansion joint, covered by a larger 

UPVC conduit. The larger conduit shall extend 150 from the flexible conduit in both 

directions and shall be secured fixed to prevent movement and sealed to prevent 

concrete entry whilst the slab is poured. 

For multi-pipe expansion boxes refer to contract drawings for details. 

108.7 Conduits in Roof Spaces 

Page 16 MEW E101


Where conduits are run in roof spaces, they shall be installed below the heat insulation 

and sarking but above any insulation on the ceiling. 

Where PVC conduits are installed in roof spaces and are likely to be walked on, they 

shall be adequately protected. 

MEW E101 Page 17


108.8 Conduits in Concrete 


Unless otherwise indicated, conduits shall not be run in the concrete topping. Conduits 

run in the fill under floor slabs shall be HD-UPVC. 

Corrugated conduits are not permitted. 

Conduits shall be securely fixed to the reinforcing rods, passing above a single layer of 

rods or between a double layer of rods, generally mid-way in the thickness of the slab. 

Attention shall be paid to routes of conduits in slabs to avoid cross-over and to keep the 

number of conduits in any one location to a minimum. Conduits in slabs shall be spaced 

not less than 75 apart. 

Conduits may cross providing they intersect at angles greater than 30 degrees and are 

tied together. The minimum cover over conduits shall not be less than the conduit 

diameter or 20. 

Conduits shall not be installed in a slab through the areas around a column to one quarter 

the distance from the column to the next column, supporting beam or wall, except to 

outlets in the area. 

Attendance during the concrete pouring to ensure that conduits are not displaced, broken 

or damaged is mandatory. 

Two working days notice shall be given to the Superintendent's Representative to inspect 

all conduits prior to pouring concrete. Sufficient time for alterations or modifications 

found necessary during inspection by the Superintendent's Representative shall be 

allowed. 

108.8.2 Conduits in Suspended Slabs 

Unless otherwise indicated, the maximum diameter of conduits in suspended slabs shall 

be 25, spaced not less than 75 apart. 

108.8.3 Conduits in General Columns 

Unless otherwise indicated, a maximum of four 20 dia. conduits are permitted in each 

column. No more than two conduits shall cross any one face of the column and all 

conduits shall be placed centrally. 

Bends in conduits entering the columns shall have a minimum radius of 300. Structural 

columns shall not be chased for conduit installation. 

108.9 Draw-In Points 

For surface run conduit systems, draw-in points shall be provided at suitable intervals not 

exceeding 30 metres for straight runs and at intervals not exceeding 25 metres for runs 

including directional changes. Draw-in points shall be agreed with the Superintendent 

prior to installation. Where used, draw-in boxes shall be of adequate size to prevent 

undue deformation of the cables. 

For underground conduit systems, draw-in boxes are not permitted. Provide pit at 

maximum 50 metre intervals. 

Materials used to lubricate cables whilst drawing-in to conduits shall be non-conductive, 

non-abrasive and non-hygroscopic. 

108.10 Conduits and Pipes for Future Use 

All conduits and pipes for future use shall be provided with polypropylene draw cords. A 

length of cord 2000 long shall be left securely fixed at the ends of each run. Conduits 

and pipes shall be labelled in accordance with Clause 603. 

Conduits and pipes terminated outside a building shall be taken beyond the line of 

paving, the draw cord shall be secured and the conduit or pipe capped, waterproofed and 

the location marked in accordance with Clause 105.5. 

Page 18 MEW E101

108.11 Wall Boxes 


Wall boxes installed in face brickwork shall be located so that the centre line of the box 

coincides with the horizontal centre line of the row of bricks nearest to the specified 

height for the box. In hazardous areas or areas defined as hazardous, the box shall be 

located at a height not less than the minimum height stipulated in the Wiring Rules. 

Wall boxes shall be securely fixed. The front edge shall be no more than 10 behind wall 

finish. Wall boxes installed in face brickwork having raked joints, or in shiplap timber 

work, shall be set with the face of the box flush with the surface of the work. 

Deep pattern wall boxes shall be used where conduits are run within brickwork, e.g. when 

bricks are "biscuited". 

Wall boxes must not be installed across the junction between different wall finishes. 

Metal wall boxes must be earthed. 

Wall boxes having sliding type lugs for attaching flush plates will not be accepted. 

Plastic wall boxes shall have threaded brass inserts for securing flush plates. 

109 CONDUIT SYSTEMS FOR COMMUNICATION SERVICES 

Conduit systems shall be mechanically continuous. 

Conduits shall be of the same type used in the rest of the installation and shall comply 

with the relevant clauses of this specification. Systems shall comply with the relevant 

conduit requirements of Clause 108 and the following requirements as applicable. 

109.1 Conduits for Telecommunication Facility Cabling 

Conduits shall be 20 dia. Where run parallel to conduits capable of enclosing power 

cables, a minimum spacing of 150 shall be observed. 

Conduits in any one installation shall originate at an approved box or cupboard, sized and 

located as indicated for use as a distribution frame. 

Each conduit shall terminate at a floor-mounted box or a flush wall box with coverplate as 

indicated. 

Not more than three outlets shall be served by one 20 dia. conduit, looping from outlet to 

outlet without the use of tees or elbows. Draw boxes within a building shall be installed 

so that cables do not need to be pulled in for a distance exceeding 12 metres. 

Draw cords shall be installed in each conduit in accordance with Clause 108.10. 

Before installation, approval shall be obtained from the local Telecommunication Authority 

Office. 

109.2 Conduits for Telecommunication Lead-In and Block Cabling 

Lead-in conduits shall originate and terminate at locations as indicated. 

Block cabling conduits shall originate and terminate at cupboards or approved wall boxes, 

sized and located as indicated for use as distribution frames. Underground conduits shall 

be heavy duty UPVC type, coloured white, and shall be spaced from other services to the 

approval of Telecom. For details on separation from, and crossing of power cables see 

relevant ACMA Specification. 

Conduits shall be sized as indicated. 

Draw cords shall be installed in each conduit in accordance with Clause 108.10. 

Before installation, approval shall be obtained from the local Telecommunication Authority 

Office. 

MEW E101 Page 19


110 CABLE TRAY, LADDER AND TROUGHING 


110.2 Cable Tray 

Cable tray, cable ladder and all accessories shall be proprietary items from a single 

manufacturer whose range includes splice connections, expansion splices, covers, risers, 

crossovers, reducers, bends and all other accessories used. Supply covers 

manufactured from the same material as the tray or ladder up to 2000 above finished 

floor level. 

Cable tray shall be manufactured from steel, hot dip galvanised after fabrication or from 

aluminium or stainless steel. 

Minimum thickness for cable tray shall be: 

1mm up to 150 wide 1.6 for aluminium 

1.2 mm from 150 up to 300 wide 2 for aluminium 

1.6 mm above 300 wide 2.6 for aluminium 

All cable trays shall be slotted similar to "Admiralty" pattern and shall have folded or rolled 

edges. The "standard" tray shall be formed with the perforations punched from outside 

the folded edge to avoid any sharp edges or burrs existing on the outside face. The 

"reverse" tray shall be perforated from the inside and shall be used in positions where 

cables are laid horizontally in the tray or alternatively, trays shall have the metal 

reinforced by folding to provide equivalent stiffness. 

Cable trays installed externally must be aluminium or stainless steel. 

110.3 Cable Ladder 

110.4 Installation 

Cable ladder shall consist of two folded steel or extruded structural grade aluminium side 

rails with cable support rungs between the two rails. The rungs shall be either welded or 

fitted to the side rails. 

Unless otherwise indicated rung spacing shall not exceed 300. Cables smaller than 13 

OD installed on cable ladder shall be run on perforated tray or ducts installed on the 

ladder. This requirement does not apply where the rungs of the ladder form a continuous 

base. 

Cable tray and ladder shall be installed by either: 

(a) surface fixing to ceilings or walls; or 

(b) suspending by hangers from ceilings, or by angle brackets out from walls. 

Fixings, hangers and angle brackets are to be spaced at a maximum distance of 1000. 

Joints shall be adequately supported. 

Where possible, cable tray and ladder shall not be mounted less than 2300 above floor 

level. Adequate access shall be provided to cable tray and ladder. Where supported by 

hangers or angle brackets, a minimum distance of 150 shall be allowed above and 600 

on one side of the tray or ladder. 

Alternative systems and supports with greater spacing may be accepted if they give equal 

rigidity and strength. 

Where cable tray or ladder span open areas they shall be capable of supporting an 

additional load of 70kg at mid span without permanent deformation. 

Cables or groups of cables shall be securely strapped to the tray or ladder using 

proprietary nylon cable ties or straps: for vertical runs at 1000 maximum; for horizontal 

runs at 2000 maximum. 

Cables shall leave the cable tray or ladder in such a manner that no cable shall be in 

contact with the side rails. In general, cable shall leave the tray or ladder in conduit, 

Page 20 MEW E101


which shall be securely anchored to the tray or ladder and with the conduit end fitted with 

a screwed cable gland to suit the cable. 

110.5 Cable Troughing 


Cable troughing, covers and fittings shall be of proprietary manufacture. Troughing shall 

have screw fixed covers, unless installed in a location not readily accessible, where clipon 

lids may be used. All fixing methods shall provide a smooth internal surface for the 

cables, for example, domed headed gutter bolts for joining sections, with the smooth 

head surface on the inside and nuts on the outside. Self tapping screws are prohibited. 

Troughing shall be installed with the cover fixing screws accessible and the covers shall 

be easily removable. The troughing shall be adequately supported in accordance with 

the Wiring Rules and, where they span open areas, they shall be capable of supporting 

an additional load of 70 kg at mid span without permanently deforming. 

Retaining clips shall be installed to retain the wiring at intervals not exceeding 1000 in all 

locations except where cable troughing is run horizontally with covers uppermost. 

Where troughing is connected to weatherproof or hoseproof (i.e. IP43 through to IP56) 

enclosures, the entry shall be made in such a manner as to prevent moisture entering the 

enclosure. 

Only PVC/PVC cables are permitted in troughing. 

110.5.2 Metal Cable Troughing 

Metal troughing shall be of an approved design and construction with removable covers 

fixed by suitably plated bolts and captive nuts. The troughing and covers shall be of 

galvanised sheet steel or aluminium of minimum 0.8 thickness and shall be free from 

rags, burrs and sharp edges. 

110.5.3 Plastic Cable Troughing 

Plastic troughing shall be of UPVC. The troughing and covers shall be robustly 

constructed from heavy gauge material to avoid sagging between supports and to avoid 

warping. All associated fittings shall be of similar material to the troughings. 

110.5.4 Skirting Troughing 

111 FIXINGS 


Skirting troughing shall be of proprietary manufacture and shall have three channels. 

Where used to extend an existing installation, the skirting troughings shall match that 

installation. Skirting troughing used for Telecommunication Authority telephone cables 

shall comply with the relevant ACMA Specifications. 

The following minimum requirements shall be observed. 

Fixings shall be secure and adequately sized to suit the weight, size, shape and location 

of the equipment being fixed. 

Fixings used in external or damp locations, or sewage treatment plants and pumping 

stations including exterior luminaires, shall be 316 grade stainless steel. All other fixings 

shall be hot dipped galvanised. 

Fixings shall be made to adequate firm supports and not to asbestos cement or 

hardboard sheeting, etc. 

Holes for screws shall have the correct clearances. 

MEW E101 Page 21


111.2 Conduits 

Holes drilled for masonry anchors shall be 6 mm deeper than the plug or anchor and 

correctly sized to the manufacturer's recommendations. Pilot holes for timber fixing shall 

not be larger than the screw root diameter. 

Plastic or fibre plugs shall not be used. 

Conduits 20, 25 and 32 dia. shall be fixed as follows: 

(a) To masonry, concrete, cement rendered walls: Ø 6 expanding sleeve masonry 

anchor to accommodate an M4.5 thread. However for 20 and 25 conduits indoors 

nylon anchors with mushroom stainless steel expansion nail may be used. 

(b) To timber: where directed fixed, wood screw No. 8 x 20, round head. Where fixed 

through fibrous cement, plaster, plaster board, etc., the screws shall be of 

sufficient length to allow for the additional thickness. 

(c) To sheet metal: No. 8 x 13 long, galvanised binding head, self tapping screws. 

(d) To steel: M5 round head screws of appropriate length tapped or bolted. 

Conduits 40, 50, 63, 65, 80 and 100 dia. shall be fixed as follows: 

(a) To masonry, concrete, cement rendered walls: Ø8 expanding sleeve masonry 

anchor to accommodate an M8 thread. 

(b) To timber: where directly fixed, steel wood screw No. 12 x 35, round head. Where 

fixed through asbestos cement, plaster board, etc, the screws shall be of sufficient 

length to allow for the additional thickness. 

(c) To sheet metal: No. 12 x 13 long, galvanised binding head, self tapping screws. 

(d) To steel: M6 round head screws of appropriate length tapped or bolted. 

111.3 Mounting Blocks 

Mounting blocks shall be fixed with four screws as specified for conduits 20, 25 and 32 

mm diameter. 

111.4 Switchboards 

The fixing of switchboards shall be as described in Clause 112.2. 

111.5 Switch Panels, Boxes 

Switch panels and boxes shall be fixed with four screws in accordance with 112.2. 

Fixings shall be one of the following, to suit the surface: 

(a) Steel wood screw, No. 8, round head, or 

(b) No. 8 electro-galvanised, binding head, self tapping, or 

(c) M5, round head. 

(d) M8 masonry anchor. 

111.6 Surface Mounted Switches 

Fixings shall be as indicated in Clause 112.5. 

Single gang switches shall be fixed with two screws and double gang and larger with four 

screws. 

111.7 Cable Troughing, Cable Tray, Skirting Troughing 

Cable troughings, trays and skirting troughing wider than 100 shall be fixed at intervals of 

not more than 1000 with two screws per fixing. Screws shall be steel wood screws, No. 

12, round head, cadmium plated or cadmium plated M6 round head screws or No. 12 

electro-galvanised, binding head, self tapping screws. 

Page 22 MEW E101

111.8 Metal Channel 


Metal channels shall be suspended using galvanised suspension rods with proprietary 

fittings. 

Where secured directly to timber, metal channels shall be fixed with M10 x 50, 

hexagonal head, coach screws. 

111.9 Hollow Block Locations 

Fixing to hollow sections shall be avoided. Where approved, it shall be by means of M5 

electro-galvanised, round head screws and spring loaded butterfly toggles. This fixing 

does not apply to ceiling fans. 

111.10 Fixing of Luminaires 

The fixing of luminaires shall be as indicated in Clause 403. 

111.11 Fixing of Ceiling Fans 

The fixing of ceiling fans shall be 2 off M6. 

112 INSTALLATION OF SWITCHBOARDS 


112.2 Fixings 

Where a switchboard has been split for installation, it shall be reassembled on site by the 

switchboard manufacturer. Particular attention shall be given to busbar joints which shall 

be torque tightened to the manufacturer's recommended torque and shall be insulated or 

coated in accordance with Clause 204.6 

If a switchboard is stored or installed in any area where building work is incomplete, it 

shall be adequately protected against moisture, corrosion, dust, paint, and mechanical 

damage. 

Floor mounted switchboards shall be fixed to the floor or other structure with M12 hot 

dipped galvanised bolts through the mounting holes provided in the base. Alternatively, a 

minimum of four hot dipped galvanised clamps may be used, each secured with an M12 

hot dipped galvanised bolt. 

Wall mounted switchboards shall be installed using an adequate number of fixings. 

However, not less than four fixings per switchboard shall be used. Fixings shall be: 

(a) To timber: 

(i) Proprietary Assemblies - hot dipped galvanised steel No. 12 wood screws of 

suitable length 

(ii) Custom-built Assemblies - 10 diameter coach screws of suitable length with 

a full washer under the head. 

(b) To masonry and concrete: 

(i) Proprietary Assemblies - stainless steel 6 diameter expanding sleeve 

masonry anchors of the projecting stud type each fitted with a full washer 

and nut. 

(ii) Custom-built Assemblies - stainless steel 10 diameter expanding sleeve 

masonry anchors of the projecting stud type each fitted with a full washer 

and nut. 

112.3 Cables, Cable Enclosure and Busway Entry and Termination 

MEW E101 Page 23


Where switchboards are fitted with cable-entry plates, one or more plates shall be neatly 

adapted to accept the incoming cable(s). Only the minimum number of plates shall be 

used thereby leaving spare cable entry plates for future cable entries. 

Cables entering a switchboard or control panel shall be glanded using non-ferrous 

metallic or plastic glands with neoprene compression seals conduit with suitable adaptor 

and locknut may be used where circuit is enclosed in conduit for its entire length. Cable 

entry shall only be through the detachable gland plate supplied with the switchboard. 

Where the sheath of a multicore cable enters either a switchboard or an electrical 

equipment enclosure, the sheath shall be: 

(i) Continued unstripped up to within less than 350 of either its lug terminations if a 

power cable or its connecting terminal block if a control cable. 

(ii) Continued unstripped after either the related conduit entry or the related cable 

gland by at least 100 to allow for cable identification marking. 

(iii) Identification marked as indicated within 100 of the end of the sheath. 

Where multicore cables with numbered cores are installed, the same numbers shall be 

continued from the switchboard to the final connections. This may require stripping of the 

outer sheath and continuation of the cores. This may also require the use of extra earth 

cables where more than one final connection is made. 

The unused cores of a multicore cable shall be terminated in the terminals provided in a 

switchboard and in an insulated screwed connector in the field. The length of the unused 

cores shall be at least as long as the longest used cores. The unused cores shall be 

looped and tied so as to be easily accessible. 

Terminations of multicore cables shall be such as to minimise the length of the 

unsheathed cores, but sufficient core length in the form of a neat loop shall be left to 

ensure that no termination is under tension and to allow for connectors to be relocated. 

Cores with the same insulation colours or numbers shall not be run together. 

There shall be no more than one conductor per terminal and all field cables shall enter 

switchboards via terminals (except instrument cables where indicated). 

Cables enclosures shall continue to the switchboard, but each cable shall be separately 

glanded at the gland plate. 

Cable and cable cores shall be identified in accordance with Clause 205 of this 

document. 

Where more than five separate surface run cables or cable enclosures are to enter a 

switchboard through the top or bottom, enclose all this wiring within U-shaped metal 

covers or ducts run from ceiling or floor to within 150 of the switchboard. Gland all cables 

when they enter the switchboard. Covers shall be earthed to switchboard cubicle, fixed to 

walls generally in accordance with Clause 112, painted to match switchboard and shall 

maintain the switchboard IP rating. The metal cover or duct shall have minimum 50% 

spare capacity for future wiring. 

Cables shall not enter through the top of externally mounted switchboards. 

To minimise eddy current effects, where single core cables rated over 300 A pass 

separately through a steel cable entry plate, the entry holes shall be joined with slots and 

the slots brazed or epoxy filled. In addition, metal cable saddles shall not be fitted over 

these cables. 

All mains and submains shall be supported or tied within 200 of the terminations. This 

support or tie shall be substantial due to the stresses under short circuit conditions. 

Where a busway is brought into a switchboard, the insulated cable entry plate shall have 

a close tolerance cut-out to fit the busbars. The busway enclosure shall be flanged at the 

switchboard and shall be bolted and sealed to the switchboard enclosure. The busway 

enclosure shall be earthed to the switchboard cubicle. Busbar clearances entering the 

switchboard shall comply with Clause 204.8. 

Page 24 MEW E101


Terminations of mains and submains shall be fully insulated or coated in accordance with 

Clause 204.6. 

112.4 Schedules and Drawings 

Neat and legible schedules and drawings as described below shall be installed in insectproof 

mounting frames having clear plastic covers and located on or adjacent to the 

relevant switchboard but away from direct sunlight. 

Schedules and drawings required are: 

(a) For each distribution board a type-written circuit schedule. 

(b) For each switchboard a copy of the relevant "as installed" lighting and power layout 

floor plans. 

(c) For each site a copy of the "as installed" drawing showing all main site reticulation 

including details and accurate positions of all spare conduits. 

(d) Drawings shall be minimum A3 size photocopies. 

113 WORK AS EXECUTED DRAWINGS 

Progressively produce Work As Executed Drawings and secure accuracy of detail for all 

work covered by this contact. 

Number Work As Executed Drawings with the suffix “X”. Provide a dated notation on 

Work As Executed Drawings indicating all changes that were made as modifications to 

exhibited drawings. 

All abbreviations shall be in accordance with AS 1000. 

Drawings shall conform to AS 1100 Drawing Practice, SAA HB7-1993-1989 Engineering 

Drawing Handbook, AS 1102 Graphical Symbols for Electrotechnology and AS 1103 

Diagrams, Charts and Tables for Electro-technology and AS3702-1989. Printing shall be 

minimum 2.5 high. 

113.1 Drawings Produced by Modification of Exhibited Drawings 

(Exhibited drawings are defined to be drawings which are part of the original 

documentation.) 

Drawings which are produced by modification of exhibited drawings shall be based on a 

clean print of the exhibited drawing which shall contain modifications and additions neatly 

marked up in red pen. At the completion of the commissioning, these marked up 

drawings shall be signed by the contractor. Five copies of these drawings shall be 

supplied. 

113.2 New Drawings Submitted by the Contractor 

Where new drawings are required to be produced as part of this contract to supplement 

the modified exhibited drawings, produce the drawings using the latest versions of 

Computer Aided Drafting software and print the drawings using a laser quality printer of 

minimum resolution 1200 x 1200 dots per inch. Use minimum 80 grams per square 

metre paper. Five prints of these drawings shall be supplied. 

114 ACCREDITATION FOR ‘CONTESTABLE WORKS” 

Where the NSW Office of Fair Trading of the NSW Department of Commerce requires 

the accreditation of Service Providers for such works as are deemed “contestable”, such 

accreditation shall be required to carry out the works as follows: 

114.1 Level 1 Accreditation 

Work on the electricity distributor’s distribution system (ie construction work relating to 

distribution network assets). 

MEW E101 Page 25



Work associated with service lines between the distribution system and the point of 

supply to the premises, energising and metering services. (i.e. construction and/or 

installation of the service line interface between the distribution system and consumer 

terminals, including metering services). 


Design work associated with Levels 1 and 2 above. (i.e. design of transmission and 

distribution works for categories overhead and underground). 

Page 26 MEW E101

PART 2 - SWITCHBOARDS AND ASSOCIATED EQUIPMENT 

201 SCOPE 

Part 2 - Switchboards and Associated Equipment 

The section covers the design, manufacture and testing of extra low voltage and low 

voltage switchboards and associated equipment. 

202 GENERALLY 

All Custom-built Assemblies for one contract shall be manufactured by the one 

manufacturer with all equipment sourced from the same suppliers for all switchboards. 

All equipment shall be positioned so as to provide safe and easy access for operation 

and maintenance. All switchboards shall be totally enclosed and shall comply with the 

requirements of AS 1939 with a minimum degree of protection as indicated in the 

relevant section herein or as indicated in the Specification. 

Switchboards shall be designed and manufactured such that they may be readily moved 

to, and installed at the indicated locations. 

If a switchboard is split for installation, all materials necessary for reassembly shall be 

provided. 

In addition to complying with the Specification, all switchboards shall comply with the 

special requirements of the relevant Supply Authority. 

202.1 Classification of Switchboards 

Switchboards are classified as Custom-built Assembly Type “CT”, Custom-built 

Assembly Type “CU”, Custom-built Assembly Type “DT”, Custom-built Assembly Type 

“DU”, Custom-built Assembly Type “DUPLUS”, Custom-built Assembly Type “DTPLUS” 

or Proprietary Assembly. 

A Proprietary Assemblies is defined as a low or extra low voltage switchgear and 

controlgear assembly available as a catalogue item, which consist of the manufacturer’s 

standard layouts and equipment. 

A Custom-built Assemblies is defined as a low or extra low voltage switchgear and 

controlgear assembly manufactured to order. 

202.1.1 Proprietary Assemblies 

The following details shall apply to Proprietary Assemblies: 

(a) They shall be front connected, surface mounted with minimum protection IP 30. 

(b) Enclosures shall be metallic. 

(c) Circuit Breakers or switches mounted in enclosures shall have the circuit 

breaker/switch toggle protruding through a metallic escutcheon. 

(d) Space shall be provided within a proprietary assembly containing circuit 

breakers/switches for a minimum of 20% spare poles or 4 spare poles, whichever 

is the greater. 

(e) Lifting handles or substantial knobs shall be provided for front covers and 

escutcheons. 

(f) All edges of all covers shall rest on the cubicle body or on a mullion. Interlocked 

covers are not acceptable. 

MEW E101 Page 27


202.1.2 Custom-built Assembly Type “CT” 

The following details shall apply to Custom-built Assemblies Type “CT”: 

(a) A Type “CT” assembly shall be a stationary “cubicle-type assembly” as defined in 

AS/NZS 3439.1:2002. 

(b) A Type “CT” assembly shall comply with AS/NZS 3439.1:2002 as defined by the 

following requirements: 

(i) Form of separation shall be Form 1. 

(ii) The degree of protection after installation in accordance with the 

manufacturer’s instructions shall be IP51 for indoor installation and IP56 for 

outdoor installation. 

(iii) Assemblies shall be front access with top and/or bottom cable entry. 

(iv) Assemblies shall be floor mounted or wall mounted. Wall mounting is 

acceptable only if the frontal area of the assembly has an area less than 2 

square metres. 

(v) For outdoor switchboards containing busbars, pollution degree 3 shall apply 

at locations further than 1km in a direct line from the coast or at altitudes 

below 1000 metres. Otherwise, pollution degree 4 shall apply. 

For indoor switchboards, pollution degree 3 shall apply. 

(vi) The following safety measures against direct contact shall apply: 

• Requirement of a key or tool to gain entry into the switchboard. (Meet 

clause 7.4.2.2.3 a) of AS/NZS 3439.1:2002.) 

• Shielding all live parts in such a manner that they cannot be 

unintentionally touched when the door is opened or the cover is removed. 

(Meet clause 7.4.2.2.3 c) of AS/NZS 3439.1:2002.) 

(vii) Assemblies shall be Partially Type Tested Assemblies or Type Tested 

Assemblies with type test certificates or satisfactory test reports for the type 

tests listed in clause 8 of AS/NZS 3439.1:2002. Documentation shall be 

available to demonstrate that the results of type tests were satisfactory. The 

testing facility shall be accredited by NATA or registered with the Association 

of Short-Circuit Testing Authorities. 

(viii) The standard Internal Arcing-Fault Test specified in Annex ZD of AS/NZS 

3439.1:2002 (limited arc, initiated on the load side of a protective device 

within the functional unit being tested) shall be met and a test certificate 

demonstrating that the results of the type tests were satisfactory shall be 

available. The testing facility shall be accredited by NATA or registered with 

the Association of Short-Circuit Testing Authorities. 

202.1.3 Custom-built Assembly Type “CU” 

The following details shall apply to Custom-built Assemblies Type “CU”: 

Note that type test certificates or satisfactory test reports for the type tests listed in 

clause 8 of AS/NZS 3439.1:2002 are not required. 

(a) A Type “CU” assembly shall be a stationary “cubicle-type assembly” as defined in 

AS/NZS 3439.1:2002. 

(b) A Type “CU” assembly shall comply with AS/NZS 3439.1:2002 as defined by the 


(i) Form of separation shall be Form 1. 




Page 28 MEW E101



(iv) Assemblies shall be floor mounted or wall mounted. Wall mounting is 

acceptable only if the frontal area of the assembly has an area less than 2 

square metres 






202.1.4 Custom-built Assembly Type “DT” 






The following details shall apply to Custom-built Assemblies Type “DT”: 

(a) A Type “DT” assembly shall be a stationary “cubicle-type assembly” or ‘multicubicle-type 

assembly” as defined in AS/NZS 3439.1:2002. 

(b) A Type “DT” assembly shall comply with AS/NZS 3439.1:2002 as defined by the 


(i) Form of separation shall be Form 3b or 4a. 





(iv) Assemblies shall be floor mounted. 






For Main Incoming Supply Compartments, Motor Starter Compartments and 

Distribution Feeder Compartments with one feeder in the Distribution Feeder 

Compartment: 



• Disconnection of all live parts that can be unintentionally touched after 

the door has been opened. (Meet clause 7.4.2.2.3 b) of AS/NZS 

3439.1:2002.) 




MEW E101 Page 29


For Common Control Compartments: 






For Distribution Compartments with one main protective device plus a 

number of subcircuit protective devices: 


clause 7.4.2.2.3 a) of AS/NZS 3439.1:2002.) for the compartment door 

and for the escutcheon. 







(viii) The special Internal Arcing-Fault Test (unlimited arc, initiated on the line 

side of the protective device within the functional unit being tested) required 

by Appendix ZD.6 of AS/NZS 3439.1:2002 shall be met and a test certificate 


available. The duration of the test shall be chosen by the manufacturer 

according to the time response of the electrical protection devices. If details 

of these devices are not known, a power supply duration of at least 100 

milliseconds shall apply. The testing facility shall be accredited by NATA or 

registered with the Association of Short-Circuit Testing Authorities. 

202.1.5 Custom-built Assembly Type “DU” 

The following details shall apply to Custom-built Assemblies Type “DU”: 


clause 8 of AS/NZS 3439.1:2002 are not required. 

(a) A Type “DU” assembly shall be a stationary “cubicle-type assembly” or ‘multicubicle-type 


(b) A Type “DU” assembly shall comply with AS/NZS 3439.1:2002 as defined by the 


(i) Form of separation shall be Form 3b or 3bi, 3bh, 3bih, 4a, 4b, 4ah, 4ai, 4aih, 

4bh, 4bi, 4bih. 













Compartment: 

Page 30 MEW E101






3439.1:2002.) 










For Distribution Compartments with one main protective device 

plus a number of subcircuit protective devices: 




202.1.6 Custom-built Assembly Type “DUPLUS” 

The following details shall apply to Custom-built Assemblies Type “DUPLUS”: 


clause 8 of AS/NZS 3439.1:2002 are not required except for the “Verification of 

short-circuit withstand test”, Clause 8.2.3 of AS/NZS 3439.1:2002, for the busbar 

system. 

(a) A Type “DUPLUS” assembly shall be a stationary “cubicle-type assembly” or ‘multicubicle-type 


(b) A Type “DUPLUS” assembly shall comply with AS/NZS 3439.1:2002 as defined by 

the following requirements: 

(i) Form of separation shall be Form 3b or 3bi, 3bh, 3bih, 4a, 4b, 4ah, 4ai, 4aih, 

4bh, 4bi, 4bih. 













Compartment: 



MEW E101 Page 31




3439.1:2002.) 















202.1.7 Custom-built Assembly Type “DTPLUS” 

The following details shall apply to Custom-built Assemblies Type “DTPLUS”: 

(a) A Type “DTPLUS” assembly shall be a stationary “cubicle-type assembly” or ‘multicubicle-type 


(b) A Type “DTPLUS” assembly shall comply with AS/NZS 3439.1:2002 as defined by 

the following requirements: 

(i) Form of separation shall be Form 4b. 













Compartment: 





3439.1:2002.) 




Page 32 MEW E101



















(viii) The special Internal Arcing-Fault Test (unlimited arc, initiated on the line 

side of the protective device within the functional unit being tested) required 

by Appendix ZD.6 of AS/NZS 3439.1:2002 shall be met and a test certificate 


available. Further to Clause ZD.2 (Relevance of Tests) of AS/NZS 

3439.1:2002, the special internal arcing-fault test shall be applicable to all 

compartments. The duration of the test shall be chosen by the manufacturer 

according to the time response of the electrical protection devices. If details 

of these devices are not known, a power supply duration of at least 100 

milliseconds shall apply. The testing facility shall be accredited by NATA or 

registered with the Association of Short-Circuit Testing Authorities. 

202.1.8 Manufacturer of the Switchboard. 

(a) Custom-built Assemblies Type “DTPLUS” 

The firm in whose name the test certificates have been issued shall completely 

manufacture the switchboard at its workshop. 

(b) Other Custom-built Assemblies 

For Custom-built Assemblies, other than Type “DTPLUS”, where a proprietary 

modular switchboard system is offered, the switchboard builder shall have been 

appropriately trained and have the appropriate level of accreditation to build the 

switchboard from the manufacturer of the modular switchboard system. 

203 FAULT LEVELS AND LIMITATION 

203.1 Fault Levels and Time of Duration 

The indicated fault level shall apply. The fault level being the prospective symmetrical 

r.m.s. value at the switchboard input terminals. Conductors and equipment shall be 

suitable for a time not less than that determined in the following manner: 

(a) On any conductor or equipment:- 

one (1) second. 

(b) On any conductor or equipment protected by a consumer's line side fuse or fast 

acting circuit breaker: the actual cut-off time or trip out time at the indicated fault 

level where it is not less than 10 milliseconds. 

Where the actual cut-off time or trip out time of the consumer's line side fuse or 

fast acting circuit breaker is less than 10 milliseconds, then the conductors and 

MEW E101 Page 33


equipment shall be suitable for the actual fault let through energy and peak cut-off 

current of the protective device corresponding to the indicated fault level. 

Equipment shall not be used at a higher fault level than that for which it has been tested, 

irrespective of fault duration. 

203.2 Fault Current Limiting 

Fault current limiting, either by fuses or suitable circuit breaker combinations shall only be 

used where indicated and shall be of the form indicated. 

Selection of fault current limiting equipment shall be in accordance with a selection table 

accepted by the relevant Supply Authority. 

203.3 Short Circuit Co-ordination 

Type 2 short circuit co-ordination in accordance with AS 60947.4.1 is required for the 

short circuit protective device, the motor contactor and the overload device if either of the 

following conditions apply: 

(a) Main busbar fault level of 31.5kA or greater at 415Volts has been specified. 

(b) Starter size is greater than 37kW when direct on line started. 

(c) Starter size is greater than 45kW when reduced voltage started. 

Type 1 short circuit co-ordination in accordance with AS 60947.4.1 is required for the 

short circuit protective device, the motor contactor and the overload device in all cases 

other than (a), (b), and (c) above, except for the following condition: 

Where ventilation fans are installed to provide a safe environment for personnel, Total 

Co-ordination for the short circuit protective device, the motor contactor and the overload 

in accordance with AS 60947.6.2 is required. 

204 BUSBARS 


204.2 Material 

204.3 Sizes 

Busbars for Proprietary Assemblies may be of the manufacturer's standard. 

Multi-pole proprietary busbar assemblies for circuit breakers shall be of an accepted type. 

When busbar systems have been verified by type testing, such arrangements are 

acceptable in lieu of the methods specified below. 

Busbars shall be arranged to ensure that the phase sequence at all switchboard 

equipment terminals is red, white and blue from left to right and from top to bottom, when 

viewed from the front of the switchboard. 

Busbars shall be hard-drawn high-conductivity copper. Square-edged busbars shall not 

be used. 

Busbar sizes in relation to current ratings shall be to AS 3000, assuming the 

switchboards are of magnetic materials, located indoors in a well ventilated room and the 

appropriate enclosure rating shall apply. However, smaller busbars may be used in 

accordance with an approved Testing Authority Temperature Rise Test Certificate for a 

switchboard with a similar internal physical configuration. 

For purposes of withstanding thermal stresses due to fault currents, active busbars shall 

be sized in accordance with AS 3439.1, unless smaller busbars can be substantiated with 

Page 34 MEW E101


an approved Testing Authority Type Test Report. (Busbars coated with copolymer 

membrane shall be regarded as insulated). 

Unless otherwise indicated, incoming busbar current rating to the first tee-off shall not be 

less than the maximum possible current rating of the frame size of the busbar protection 

device. However, for main switchboards with no main protection device, the incoming 

busbar current rating shall not be less than the current rating of the consumers mains. 

Tee-off busbars to other controlling devices shall have a current rating equal to the 

maximum frame size rating of that controlling device. 

In determining other than incoming and tee-off busbar sizes (eg vertical droppers etc), 

the actual frame size rating of the controlling devices and spare spaces shall be used and 

the load diversity reduction factors given in AS 3439.1 shall be applied. Busbars so sized 

need not exceed the size of that section's incoming busbars. Accepted proprietary 

busbar assemblies shall not be used at higher than the assigned ratings. 

Busbars connected to fault current limiters shall be rated to 100% of indicated current 

limiter rating. 

MEW E101 Page 35


204.4 Jointing 

204.5 Supports 

Busbar jointing shall maximise the copper-to-copper contact area under the "shadow 

area" of the bolt head and nut. 

Bolt holes shall be round, square edged with a maximum bolt clearance of 1. Deburring 

shall be the minimum necessary to remove any projections. 

Joint surfaces shall be flat and shall be deliberately roughened by sanding or draw filing 

immediately prior to making the joint. Tinned or electroplated joints are an acceptable 

alternative. 

Where the fault rating of any busbar section of a switchboard does not exceed 14kA, and 

for all proprietary multi-pole busbar assemblies, the minimum requirements shall be 

plated steel commercial bolts to AS 1111, with minimum strength grade of 4.6. 

Where the fault rating of any busbar section of a switchboard exceeds 14 kA, the 

minimum requirements for all size busbars throughout that section shall be M10, plated 

steel precision bolts to AS 1110 with minimum strength grade of 8.8, which shall be 

confirmed by the marks "M" and "8.8" appearing on the bolt head. This applies to busbar 

joints and where busbars are bolted to insulators and support. 

For the purposes of joint inspections, a joint as nominated by the Superintendent shall be 

stripped of its finish coating dismantled, reassembled and re-finished during the factory 

inspection. 

Where busbars are bolted to proprietary equipment, the proprietary bolts and terminating 

methods supplied by the manufacturer are acceptable. 

The number of bolts used per joint shall be consistent with first grade jointing practice. A 

minimum of two bolts per joint is preferred. 

Busbar jointing bolts shall not be used to support the busbar. 

For both commercial and precision bolts, use one plated steel full flat washer on each 

side of the joint, and one plated steel full nut (no spring or serrated washer, or locknut). 

The full nuts shall be torque-tightened to the bolt manufacturer's recommended levels. 

For both commercial and precision bolts, use one plated steel full flat washer on each 

side of the joint, and one plated steel full nut (no spring or serrated washer, or locknut). 

The full nuts shall be torque-tightened to the bolt manufacturer's recommended levels. 

Written agreement shall be obtained to alternative jointing methods, before commencing 

manufacture. 

Busbar support spacings shall be determined by reference to "Copper for Busbars" 

issued by the Copper Development Association and to other appropriate engineering 

principles and data. Spacings greater than those indicated by these references shall be 

substantiated by an approved Testing Authority Type Test Report. 

Busbar supports shall be made of non-hydroscopic insulating material and shall be 

capable of holding busbars at a temperature of 105ºC. Supports shall be capable of 

withstanding thermal and magnetic stresses associated with relevant fault levels and 

times of duration. 

Supports shall be of adequate size and shall rigidly hold all busbars by being rigidly fixed 

to the cubicle where possible. Floating supports shall be kept to a minimum. 

Clamp type supports shall suit the busbar cross-sectional shape so as to minimise 

distortion and migration of busbar insulation or coating during normal service. 

Page 36 MEW E101

204.6 Prevention of Arcing Faults 

204.6.1 Rigid Insulation 


Where hook-stick links, open blade type fuse links or the like are installed within a 

switchboard, suitable rigid, fixed insulating barriers shall be provided to prevent 

inadvertent electrical contact between phases by a foreign straight metallic object. 

Barriers shall be provided on both sides of each link or fuse link (eg four barriers for a 

three phase set). 

204.6.2 Coating of Busbars and Terminations 

Active busbars shall be coated with polyethylene. All joints and jointing bolts not so 

coated shall be either taped, insulated with air drying plastic coating or have a water 

based copolymer membrane coating applied. 

As an alternative, all active busbars including joints and jointing bolts may be coated with 

a water based copolymer membrane coating. 

Those parts of busbars which are fully encapsulated need not be coated. One system 

deemed to be equivalent to encapsulation is proprietary close fitting busbar insulation 

mouldings not less than 1.0 thick. 

In the case of equipment providing integral shrouding between the main active terminals, 

the coating shall not extend into the shrouded area. 

Mating surfaces of the main plugs or connections of demountable or withdrawable 

functional units shall not be coated. 

Busbar flags for the connection of future equipment shall not be coated, but shall be 

covered with readily removable insulating material of minimum thickness 0.4. 

204.6.3 Application of Busbar Coatings 

(a) Polyethylene 

Polyethylene shall be applied by a fluidised bed process in which the material is 

directly cured onto the bars. 

Preparation of the busbars and method of application shall be strictly in 

accordance with the supplier's recommendations. 

The thickness of the coating shall be not less than 0.4 and the minimum dielectric 

strength of the coating shall be 2 kV rms for one minute. 

The colours shall be either the correct phase colours or all white with phase colour 

bands. 

(b) Acrylic Copolymer Membrane Coating 

Before coating, all surfaces shall be cleaned down, treated with an etch cleaner 

and then completely dried. One substantial coat approximately 0.15 to 0.2 thick 

shall then be applied. 

The material used shall have a minimum titanium dioxide content of 10%. 

Coating colour shall be cream with phase colour bands. 

Care shall be taken to prevent the coating being applied over any insulation 

between phases or phase to earth at busbar barriers and supports or on any 

switchboard equipment. 

(c) Taping at Joints 

Taping shall be with non-adhesive stop-off half lapped to achieve a thickness not 

less than 0.4 and the ends shall be tied off. The colour shall match the adjoining 

busbar coating. 

(d) Air Drying Plastic Coating at Joints 

MEW E101 Page 37


204.7 Phase Identification 

Plastic coating material shall achieve a tensile strength of greater than 17 MPa and 

have a minimum ultimate elongation of 300%. 

Application of air drying plastic coating shall be in accordance with the 

manufacturer's recommendations to achieve a thickness of not less than 0.4. 

Coating colour shall match the adjoining busbar coating. 

Busbars shall be identified by minimum 25 wide colour bands neatly and permanently 

applied and located at not more than 500 intervals along the active, neutral and earth 

busbars with a minimum of one colour band for each busbar piece. Adhesive type 

material is not acceptable. 

MEN links shall have green-yellow and black bands. 

Colours shall be red, white and blue respectively for the phases A, B, and C, black for 

neutral and green-yellow for earth. 

204.8 Busbar Clearances 

Clearance between phases and phase to earth shall be not less than that required by AS 

3000. All busbars shall be treated as being bare. 

Where busbars are connected to proprietary equipment, clearances less than that 

required by AS 3000 are acceptable provided the busbars are insulated. 

204.9 Cable Connection Flags 

All equipment, having main terminals inadequate for the cable size, shall be fitted with 

busbar flags. The size of the flags shall be appropriate for the cable lugs to be 

terminated and shall have a current rating of not less than the maximum frame size of the 

equipment. Busbar flags shall be suitably supported. 

204.10 Neutral and Earth Busbars 

The ratio of neutral to active busbars size shall be equal to that of the incoming cable 

cores. 

Earth busbar cross sectional areas shall be in accordance with AS 3000. 

The minimum cross sectional area of the neutral and earth busbars throughout the 

switchboard shall be sized in accordance with Appendix C of AS 136 to suit 50% of the 

indicated fault level for 100% of the time of duration (eg a fault level of 43 kA for one 

second requires a minimum uninsulated busbar of 124mm 2 cross-sectional area). 

The metal frames of switchboard cubicles and equipment (eg air break circuit breaker, 

FCU's etc) shall be effectively bonded to the earth busbar. To achieve a good metal-tometal 

contact, painted surfaces shall be stripped and given a corrosion resistant coating 

just prior to bolting to the earth busbar. 

204.11 Flexible Busbars Take Offs 

Notwithstanding other requirements of this document, the conductors between the rigid 

busbars and the supply side of a single functional unit may consist of flexible, insulated 

copper woven busbars which are forged to a solid unit at both ends. In any case, comply 

with Clause 7.5.5.1.2 of AS/NZS 3439.1:2002. 

205 CABLING 


Interconnecting cables may be used instead of busbars for all ratings and shall comply 

with the requirements of this clause. 

Page 38 MEW E101


Cables are not to be used to link adjacent circuit breakers where multi-pole busbar 

assembly can be used for this purpose. 

Except for I/O cabling, internal cabling shall be at least V75 insulated with stranded 

copper conductors of a size not less than that determined from AS 3008.1 for enclosed in 

free air conditions but shall not be less than 1.5mm 2 . Cable sizes determined shall 

include the principles explained in Clause 204.3 and 204.10. 

Digital PLC I/O wiring shall be carried out in minimum 0.5mm 2 PVC flexible cable. 

The current rating of cables between fault current limiting fuses and a fixed setting circuit 

breaker used to limit the maximum demand, need not exceed the current rating of that 

circuit breaker. 

Cables shall be adequately supported and run clear or busbars and metal edges. 

Adhesive supports are not permitted. 

Phase, neutral and earth cables shall be capable of withstanding the maximum thermal 

and magnetic stresses associated with the relevant fault level and time of duration. 

Thermal performance shall be based on AS 3008.1. 

All cables shall be neatly run and shall be supported and tied at maximum 150 intervals 

unless enclosed in a duct. 

Ducts shall be of a slotted type adequately sized for present and all anticipated future 

cables. 

Switchboard design shall allow wiring to be run to future equipment without removal of 

existing equipment. 

All cables shall have suitable palm type crimp lugs fitted. Crimp lugs shall be fitted with 

the correct tooling. Flexible cables to be terminated in tunnel terminals shall be fitted with 

insulated sleeved ferrules. For all sewage treatment works and sewage pumping stations, 

immerse the exposed conductor at the end of the flexible cables in petroleum jelly prior to 

termination. 

Looping of earth cables is not permitted, and all earth cables shall terminate at an earth 

link or at a minimum M6 earthing stud adjacent to the equipment. 

Cables shall be arranged to ensure that the phase sequence at all switchboard 

equipment terminals is red, white and blue from left to right and from top to bottom, when 

viewed from the front of the switchboard. 

Control wiring shall originate from white phase throughout an installation. 

205.2 Cable Identification 

Colours 

Cable insulation shall be coloured in accordance with the following table: 

Phase wiring (A, B & C) - red, white and blue 

Voltmeter and current transformer connections - red, white, blue and black 

240 V control active (controlled by isolator on the board) - grey 

240 V control active (not controlled by isolator on the board) - orange 

240 V neutral - black 

ELV AC active - brown-red 

ELV AC common - brown-white 

ELV devices eg thermistor - brown 

ELV DC positive - blue-red 

ELV DC negative - blue-white 

Telemetry - violet 

MEW E101 Page 39


Earth - green-yellow 

Cables listed in two colours (eg brown-red) shall consist of a base colour (ie brown) and a 

spiral trace colour (ie red). Cable trace colours shall cover between 20% and 40% of the 

cable surface and extend the full length of the cable. 

As an alternative for cables above 50mm 2 , all double insulated cables, phase 

identification may be 25 wide heat shrink bands of the colours tabulated above applied at 

each end and at not more than 500 intervals along the entire run. 

Identification 

(a) Control Wires 

All control wires shall be individually identified at each end. All control cables shall 

have the same identifying number over its entire length even when it passes in and 

out of a terminal block. 

(b) Multicore Control Cables 

Each cable core shall be individually identified with a number in numerals and spelt 

out in letters. Such identification shall be in black on to the cable cores during 

manufacture. Cable cores shall be consecutively numbered. 

(c) Plastic Cable Ferrules 

Cable cores which do not have integral number identification shall be identified 

using proprietary cable ferrules. Cable ferrules shall be flexible plastic sleeve type 

Z type with indelible alphanumerics. The cable ferrules shall be designed for the 

cable core diameter. The use of Critchley Multi-Mark and Grafoplas identification 

systems is acceptable. 

(d) Cable Sheaths Identification 

All cable sheaths shall be identified at both ends. Identification shall include cable 

number prefixed by J for instrumentation, C for control and P for power, circuit 

name (e.g. Pump 1) and type and size of cable (e.g. 3C + E 2.5 mm²). 

Identification shall be neat, permanent and legible and the following will be 

acceptable: 

- Stamped aluminium tags 

- Proprietary write-on tags 

(e) Visibility 

Cable and core identification shall be fully legible and visible from the front of the 

switchboard, control panel, equipment etc. ferrules, embossed alphanumerics, 

tags, etc., shall be arranged such that all letters and numerals are in line and can 

be readily read from the front without manipulation. Alphanumerics shall be 

vertically upright on horizontal cables and cores, and shall be read from the right 

hand side on vertical cables and cores. 

205.3 Large Cables (Cables above 6mm²) 

Not more than one cable shall terminate in a tunnel terminal, and not more than two 

cables shall terminate at any other connection point or terminal. 

Active links shall comply with paragraphs (a) to (d) of Clause 206.2. 

Large cables shall not be run to hinged panels or doors. 

In addition to the cable supports described in Clause 205.1, rigid non-metallic fixings to 

the switchboard cubicle shall be provided within 200 of all terminations and at not more 

than 400 intervals along the entire run. 

If the cables are in a duct, the intermediate fixings shall be within the duct. 

To minimise eddy current effects metal cable saddles shall not be fitted over single core 

cables rated over 300A. 

Page 40 MEW E101


For arcing fault prevention, large cable terminations shall be treated in accordance with 

Clause 204.6 

205.4 Small Cables (Cables up to and including 6mm ²) 

Each cable core shall be marked at both ends with neat fitting ring type identification 

ferrules and the markings shall agree with the endorsed circuit diagram. Markings shall 

comply with AS 1103. 

Marked cables to connect with external controls shall terminate in correspondingly 

marked terminals located within the switchboard, adjacent to the external cable route. 

Cables to items of equipment mounted on hinged panels or doors shall run at the hinge 

side in such a manner as to not impede opening of the panel or door. Spiral type 

sheathing shall be applied to the cables between the fixing at the switchboard cubicle and 

the fixing on the panel or door. 

206 ACTIVE, EARTH AND NEUTRAL LINKS 

206.1 For Proprietary Assemblies 

Links for Proprietary Assemblies may be the manufacturer's standard. 

206.2 For Custom-built Assemblies 

For small cables (up to and including 6mm 2 ), two screw tunnel terminals with minimum 

M4 brass or plated steel screws shall be provided. Screw diameter shall be not less than 

70% of tunnel diameter. 

For large cables (above 6mm 2 ), one of the following is acceptable: 

(a) Minimum M8 brass screws, tapped and sweated into a minimum 6 thick brass or 

copper bar. A full nut and flat washer shall be provided for each stud. 

(b) Minimum M8 hexagon head plated steel or brass set screws with flat washer, 

tapped into a brass bar. The length of engaged thread shall be not less than the 

diameter of the screw. 

(c) Minimum M8 plated steel screws through clearance holes not more than 1.0 larger 

than the screw diameter, in a minimum 6 thick busbar. A plated full nut and two 

plated flat washers, one under the head and one under the nut, shall be provided. 

This method shall only be used where there is adequate spanner access to both 

the screw head and the nut. 

(d) Tunnel terminals with one Allen head grub screw per terminal of diameter not less 

than 90% of the tunnel diameter. 

(e) Approved nut tightened line-tap type clamp which securely clamps the conductors 

and prevents the cable strands from spreading. 

For aluminium cables, only methods (a), (b) and (c) are acceptable. 

Spring washers shall not be used at links. 

Each incoming and outgoing switchboard control shall be numbered with consecutive 

numbers starting at 1 and no number shall be repeated on the same switchboard. The 

same number shall appear at the corresponding neutral and earth terminals. 

Switchboards with 36 poles or less and where single pole circuit breakers can be fitted 

shall have one neutral and one earth terminal for each pole. Switchboards with more 

than 36 poles shall have one neutral and one earth terminal for every indicate circuit with 

a minimum of 36 neutral and 36 earth terminals. 

Where spare spaces are indicated, one neutral and one earth terminal shall be provided 

for each pole space or indicated future control. In determining the type of spare 

terminals, the ratio of small cable to large cable terminals for the indicated circuits shall 

MEW E101 Page 41


be maintained, except that no less than two spare neutral and two spare earth large cable 

terminals shall be provided. Spare large cable terminals are not to be identified with a 

circuit number. 

Where the number of interchangeable circuit breaker poles in a switchboard exceeds 36, 

at least one neutral link and one earth link shall be provided at the top and at the bottom 

of the circuit breaker section. Generally, it is preferred that the links be of equal size 

although consideration must be given to circuit grouping and the links allocated 

accordingly. For example a 60 pole switchboard could have terminals 1 to 24 at the top 

and 25 to 60 at the bottom. The conductor linking the top and bottom neutral links shall 

have a current rating of not less than the active conductors on the load side of the 

controlling device. 

Neutral links shall be mounted on an insulated base. 

All earth links shall be bonded to the main earthing conductor with a conductor suitable 

for 100% of the indicated fault level for 100% of the time of duration. Bonding by means 

of cubicle contact is not acceptable. 

Control circuit neutrals and earths shall not occupy terminals designated for outgoing 

cables. 

207 EQUIPMENT 

207.1 Compliance with Australian Standards 

Proof of compliance with the relevant Australian Standard shall be provided if requested 

by the superintendent. Such proof shall comprise a complete Test Certificate from an 

accepted independent Testing Authority or a Certificate of Suitability issued by an 

Australian Electricity Authority. 

207.2 Ambient Temperature 

All outdoor SCA's equipment shall be rated for min 60°C. All equipment for indoor SCA's 

shall be rated at min 50°C. 

207.3 Miniature Overcurrent and Moulded Case Circuit Breakers 

Circuit breakers with current ratings of up to and including 100 A, and interrupting 

capacities up to but not including 10 KA, and/or a projected panel mounting area not 

exceeding 4000 sq. mm per pole, shall comply with AS 3111. 

This shall include Miniature Overcurrent Circuit Breakers fitted with or incorporating a 

current operated core balance core leakage relay or auxiliary contacts. 

Circuit breakers with an interrupting capacity of 10 kA and above shall comply with AS 

2184. 

The trip current rating shall be clearly visible with the switchboard covers in place. 

Separate labels on the switchboard cover for this purpose are not acceptable. 

Identification of the contact positions shall be clearly marked on the circuit breaker in a 

contrasting colour. 

Horizontally mounted circuit breakers shall be capable of successful operation under full 

load and short-circuit conditions in the horizontal position. 

Where switchboards are supplied as a group of one or more switchboards from the one 

manufacturer, then within that group all circuit breakers of each frame size shall be of the 

same manufacture. However, the selection of all circuit breakers for any project shall 

ensure full overload and short circuit compatibility with each other and with all existing 

circuit breakers. This latter requirement is particularly important where, for fault current 

limiting, the use of series circuit breaker combinations is indicated. 

Page 42 MEW E101


To limit the possibility of low level short circuit arcing faults, all adjustable short circuit trip 

settings are to be set to the "low" position. 

To assist in phase balancing, circuit breakers for two phase circuits shall be either three 

pole circuit breakers or two pole circuit breakers that occupy two pole spaces. 

Where locking is indicated, circuit breakers shall be provided with the facility for locking in 

the "open" position. 

207.4 Drawout Circuit Breakers and Tripping Battery 

207.4.1 Drawout Circuit Breaker 

207.5 Fuses 

Drawout circuit breakers shall comply with AS 1930 and shall incorporate the following 

features: 

(a) Rated duty shall be "uninterrupted type" for a non-ventilated enclosure. 

(b) "Rated short circuit breaking capacity" shall be not less than the switchboard fault 

level 

(c) Closing shall be either: 

(i) "Independent manual closing", or 

(ii) "Stored energy closing" with a separate release button. 

(d) Drawout construction 

(e) Auxiliary contacts shall be rated to AC-11 requirements with a minimum rated 

operational current of 6 A, 240 V. A minimum of one spare normally open contact 

and one spare normally closed contact shall be provided. 

(f) Ability to be padlocked in the "open" position. 

(g) Automatic main contact shutters. 

(h) A door interlock to prevent the compartment door being open while the circuit 

breaker is in the "closed" position, except where the door serves merely as a cover 

to the circuit breaker and its operating mechanism. 

(i) Racking gear shall prevent the withdrawal or engagement of the circuit 

breaker when its contacts are closed and shall have the following positions: 

(i) Connected 

(ii) Test/Isolate 

(iii) Disconnected. 

(j) All stored energy devices shall be automatically discharged before any racking 

operation. 

(k) Separate racking handles and all special installation, operation and servicing tools 

shall be supplied. 

(l) The protection system shall be either: 

(i) An integral part of the circuit breaker, either solid state protection relay type 

or adjustable magnetic instantaneous relay type, or 

(ii) externally mounted relays operating a d.c. trip coil, either adjustable 

induction disc type, or solid state protection relay type. 

(m) An earthing connection shall be provided to earth the movable carriage and 

mounting frame. This connection shall "make" no later than and "break" no earlier 

than any other connection. It shall be suitable for busbar termination. 

Fuses shall comply with AS 2005 (All Parts). 

MEW E101 Page 43


Fuses shall be suitable for the fault level of the installation and shall discriminate properly 

with other protective equipment. Let-through energy and peak current cut-off shall suit 

the protected equipment. 

Fault current limiter fuse links shall be held in proprietary holders, and shall be mounted 

for withdrawal directly towards the operator. Holders for open blade type fuses shall have 

barriers complying with Clause 204.6.1. 

Where fuse extraction handles are required, they shall be clipped inside the switchboard 

cubicle adjacent to the fuses. Where the fuses are located behind more than one cover, 

one handle shall be provided behind each cover. 

Fuse links shall clearly state the name of the Australian manufacturer or distributor. 

A minimum of three spare fuse links shall be provided for every fuse size included in the 

switchboard, with the exception of fuses installed solely for fault current limiting. The 

spare fuse links shall be mounted in clips in the spare parts cabinet or space described in 

Clause 214, and where more than one size is provided, rating labels shall be fitted. 

207.6 Fuse Combination Units 

Fuse combination units shall comply with AS 1775 and shall incorporate the following 

features: 

(a) Be either of the totally enclosed type or constructed such that the fixed live parts of 

the switches and fuses are fully and directly shrouded to prevent faults developing 

between phases by introduction of a foreign straight metallic object. The shrouding 

shall be fully effective throughout the entire movement of the air break switch. 

(b) Switching shall be "independent manual operation". 

(c) Rating duty shall be "uninterrupted type". 

(d) Derating shall be applied, if appropriate, for units mounted in a compact formation 

(eg stacked formation). 

(e) Utilisation category shall be in general AC-21 minimum, with AC-23 for motor 

loads. 

(f) Ability to be padlocked in the open position, if indicated. 

(g) Contact position shall be clearly shown both with the cover in place and with the 

cover removed. A secondary indication independent of the handle position shall 

additionally be provided. Where the fuses are mounted in a withdrawable carriage 

which ensures isolation from the supply before access to the fuses is possible, 

then the secondary indication may be omitted. 

(h) Identification of the contact position shall be clearly marked on the F.C.U. in a 


207.7 Main Switches 

This clause shall apply to main switches on main switchboards and local main switches 

on distribution boards. 

Main switches shall comply with AS 1775 and shall be suitable for fault-making/loadbreaking 

duties. Suitable switches are automatic circuit breakers, fused F.C.U.'s and 

fault-making/load-breaking switches. 

Non-automatic breakers, F.C.U.'s with solid links, or load-making/load-breaking style 

switches are not acceptable unless they have been tested for fault-making/load-breaking 

duties to AS 1775. 

The following features shall be incorporated: 

(a) Type of switching shall be "independent manual operation". 

(b) Rated duty shall be "uninterrupted type" for a non-ventilated enclosure. 

Page 44 MEW E101

207.8 Contactors 


(c) "Rated short time withstand current" shall be not less than the switchboard fault 

level. 

(d) Utilisation category shall be in general AC-21 minimum, with AC-23 for motor 

loads. 

(e) Identification of contact position shall be clearly marked on the switch in a 


AC contactors shall comply with AS 1029. 

The following details and minimum features shall apply: 

(a) Block style electromagnetic, air break type generally from the one manufacturer. 

(b) Quiet in operation. 

(c) Rated duty "intermittent class .03". 

(d) Utilisation category "AC-3" or "DC-3" as applicable. 

(e) Mechanical endurance "class 10". 

(f) Contact life 1 million operations at AC-3 or DC-3 as applicable. 

(g) Three phase contactors shall have minimum rating of 16 A, 415 V at category 

AC-3. For motor below 0.5 kW 8A is allowed.. 

(h) Be designed to allow for fitting of auxiliary contacts with rating (I e ) of 4 A at 240 V 

a.c. 

(i) Series or parallel contacts shall not be used to achieve the required ratings. 

207.9 Control Switching Devices 

Control switching devices eg instantaneous relays, time delay relays, control switches 

and push button switches, shall comply with AS 1431. Contact arrangements and 

numbering to EN50011 is required. 

207.9.1 Instantaneous Relays 

Instantaneous relays shall be of the type and contact arrangement as indicated but, if not 

indicated, shall be Type 3 as described below. Where practical, relays shall be selected 

from the one manufacturer's range and must be common in regard to contact switching in 

any one voltage range. 

Where relays are used as on interposing relay between a PLC and other equipment, the 

relays may be Type 2. 

Type 2 relays shall be 11 pin round plug-in with Push to test feature. Where specified as 

a DC relay, they shall be complete with suppression diode and an indicator to show 

energisation bases shall have screw connections with scissor action contacts. 

Relay coils shall be capable of operating under the required duty in the surrounding 

ambient conditions with a supply voltage variation of ± 1-%. 

Where indicated a minimum of 1 N/O and 1 N/C spare contacts shall be provided within 

each relay. 

Relays shall have visual indication of contact operation. Type 3 relays shall be of the 4/8 

pole style and shall be of identical width in both configurations. 

The following details and minimum features shall apply: 

MEW E101 Page 45


Relay 

Type 

Mech. Life 

x 10 6 

Operations 

Base Contact Rating Min. No. 

of Contact 

Elements 

Plug-In 

Unit 

Retention 

Clips 

1 5 Plug-in 1.25I L 2 Yes 

2 10 Plug-In 7A @ 240V @ COS Ø= 0.4 2 Yes 

3 10 Fixed Mounting 5A @ 240V 4 - 

207.9.2 Time Delay Relays 

Time delay relays shall be adjustable over the entire range, as indicated, and the timing 

range shall not exceed 400% of the indicated setting. 

Time delay relays shall be capable of operating under the required duty in the 

surrounding ambient conditions with a supply voltage variation of ± 10% and a timing 

repeat accuracy of ± 2.5%. The details and minimum features indicated in the table in 

Clause 207.9.1 excluding minimum number of contact elements, also shall apply to time 

delay relays. 

Unless otherwise indicated, time delay relays shall be electronic operation. 

Electronic relays shall incorporate a LED which shall indicate energisation of the output 

relay. 

207.9.3 Control Switches 

Control switches shall be of the rotary switch type with cam operation and switch 

positions arranged with a displacement of 60º and, if an "OFF" position is required, it shall 

be located at the "12 o'clock" position. 

Contacts shall have minimum rated operational current (I e ) of 6 A at 240 V a.c. to 

utilisation category AC-15 or AC-23. 

Escutcheon plates shall be rectangular and shall allow function and switch position 

labelling to be included on the plate. Escutcheon plates shall be silver with black 

lettering. Where control switches are input to a PLC the contacts shall be low resistance 

wiping type. 

207.9.4 Push Button Switches 

Push Button switches shall be of the oil-tight type with minimum rated operational current 

(I e ) of 4 A at 240 V a.c. to utilisanaln category AC-15. Buttons shall be not less than 22 

diameter and shall all be selected from the same size range. Each switch shall be 

provided with a legend plate indicating its functions. In the case of latched "STOP" or 

"EMERGENCY STOP" push buttons instructions for releasing the latch shall be included 

either on the legend plate or on the face of the button. 

Buttons shall be colour coded to AS 1431 Part 2, Table 5.4.1 or the Drawings. 

In addition, illuminated push button switches shall comply with requirements of Clause 

207.20. 

Page 46 MEW E101

207.10 Phase Failure Relays 


Phase failure relays shall be of the electronic type and shall detect under voltage (80% of 

nominal voltage), voltage or phase angle imbalance and reverse phase sequence. The 

sensing circuit shall reject signals of other frequencies, i.e. ripple control and spurious 

voltage spikes; either in the supply or induced by the protect loads. 

The relay shall be suitable for protecting motor loads under starting and running 

conditions. A LED shall indicate when the power supply is normal. 

Contacts shall have minimum rated operational current (I e ) of 5 A at 240 V a.c. to 

utilisation category AC-15. 

Each relay shall be individually protected by external protective devices of maximum 10 A 

rating. 

207.11 Residual Current Devices (RCD) 

RCD's shall be current-operated (core balance) type to AS 3190. Rated trip current shall 

be 30 mA unless otherwise indicated. 

All equipment associated with an individual earth leakage circuit section shall be grouped 

together in a regular and logical manner. 

207.12 A. C. Motor Starters 

207.12.1 General 

Unless otherwise indicated and except where limitations on starting current preclude their 

use, motor starters shall be of the D.O.L. type. Each starter shall be complete with 

overload protection incorporating at least one of the classes of motor protection 

described in Clause 207.12. 

Where indicated, further protective devices, as described by the classes of motor 

protection in Clause 207.12, shall be incorporated. 

Motor starters shall have the following minimum ratings: 

Rated duty : intermittent duty 0.1 

Utilisation category : AC3 

Mechanical endurance : Class 10 

One million on-load operating cycles 

Minimum 16 A current rating 

The voltage rating of the coil shall be such as to be compatible with other components in 

the control circuit and the operating voltage applicable. 

Contactors used in motor starters shall be designed to allow the fitting of auxiliary 

contacts with minimum rating (I e ) of 4 A at 240 V a.c. AC 15 

Motor starters shall be rated for motor full load currents and shall be suitable for 

operation in the enclosures used. 

Supply each motor starter with control field isolation terminals to disconnect power to the 

contactors. 

207.12.2 Direct-On-Line Starters 

These shall incorporate a direct switching electromagnetic contactor together with 

overload protection relay, offering overload protection in each phase of the supply, 

suitable for starting motors "direct-on-line" in accordance with AS 1202 Part 1. 

MEW E101 Page 47


207.12.3 Reduced Voltage Starters 

Reduced voltage starters shall be of the electromagnetically operated type complying with 

AS 1202 Parts 2 and 3, offering overload protection in each phase of the supply or motor 

circuit and incorporating the following features. 

(a) Star Delta Starter 

Star-delta starters shall include: 

(i) One (1) main line contactor or equivalent. 

(ii) Star and Delta contactors mechanically and electrically interlocked to 

prevent simultaneous operation. 

(iii) One (1) triple pole overload relay, fitted to the line contactor. Where the 

star-delta starter configuration is such that the overload is connected into the 

motor phase winding circuit, a nameplate shall be fixed to the starter stating 

the full load current of the motor phase wind, i.e. 58% of the full load line 

current of the motor. 

(iv) One (1) time delay relay with nominal 0-30 second adjustable time delay 

period to control the star to delta switching contactors. 

(v) Where closed transition type starters are indicated, suitably rated stainless 

steel resistor banks, transition contactor and time delay relay shall be 

provided. 

(b) Auto-Transformer Starters 

207.12.4 Reversing Starters 

Auto-transformer starters shall be parallel, closed transition (Korndorfer 

connections) type in accordance with Diagram B1, Appendix G of AS 1202, Part 3, 

utilising three poles of the star contactor ("K1"), Mechanical and electrical 

interlocking shall be employed between the star contactor ("K1") and the run 

contactor ("K3") to prevent simultaneous closing. 

Each auto-transformer starter shall include: 

(i) One (1) three core auto-transformer tapped at 50%, 65% and 80% and rated 

for enclosed operation. Provide Auto-transformers with insulation class 155 

to AS 2768. Provide Auto-transformers suitable for a minimum of 12 starts 

per hour. House each auto-transformer in its own segregated compartment. 

(ii) One (1) triple pole thermal overload relay. 

(iii) Star, auto-transformer and run contactors (K1, K2 and K3). 

(iv) One (1) set of three embedded thermistors, complete with manual reset, 

operating relays and indicators, to protect the auto-transformer. 

(v) One (1) time delay relay with nominal 0 to 30 second adjustable time delay 

period to control the start and run contactors. 

Reversing starters shall generally comply with Clause 207.12.1 and shall include: 

(i) Two (2) main line contactors, mechanically and electrically interlocked to prevent 

simultaneous closure. 

(ii) One (1) triple pole overload relay. 

(iii) One (1) time delay relay with nominal 0 to 30 second adjustable time delay period, 

to prevent plugging of the motor. 

Page 48 MEW E101

207.12.5 Electronic Soft Starter 


Electronic soft starters shall comply with AS 1202 Part 5 and be selected from a 

manufacture with a range from 10A to 500A using a three wire rating. 

The starter shall incorporate the following features:- 

(i) Automatic restart in the event of failure. 

(ii) Breakaway torque adjustment. 

(iii) Motor starting current limit adjustment. 

(iv) Adjustable acceleration time. 

(v) adjustable deceleration time. 

The starter shall incorporate: 

(i) Phase loss trip. 

(ii) Shorted SCR trip 

(iii) Open circuit output trip. 

(iv) Motor stalled trip. 

The starter shall incorporate a RL snubber network for dV 

suppression and be capable 

dt 

of withstanding (min) 1400 VDC PIV: Temperature rating shall be 0-60°C minimum. 

207.13 Motor Protection Devices 

207.13.1 Three Phase Motor Protection 

Three phase motors required by AS 3000 to have overload protection shall be protected, 

as indicated, by one or more of the means listed in Clause 207.13.2 and shall in all cases 

include thermal overload protection connected on the load side of appropriate contactor. 

The protection equipment shall operate in the event of: 

(a) Overloading in continuous or intermittent service. 

(b) Extended acceleration times. 

(c) Failure of one phase resulting in single phasing. 

(d) Mechanical seizure of the rotor. 

207.13.2 Motor Protection 

Thermal Overloads 

Thermal overload relays shall comply with AS 1023, Part 2 and shall incorporate the 

following features: 

(a) An overload sensing element in each phase. 

(b) Ambient temperature compensation shall be such that the temperature of the air 

surrounding the overload relay within the starter enclosure can vary over the range 

from 5ºC to 50ºC without effectively altering the tripping time of the relay. 

(c) Single phasing detection by differential trip bar mechanism which shall operate at 

60% of motor full load rating under single phasing conditions. 

(d) An integral manual reset button. 

(e) One N/O and one N/C auxiliary contact with minimum operational current (I e ) of 4 

A at 240 V a.c. 

(f) Except where operated separately by C.T.'s, T.O.L.'s shall be directly connected to 

contactor by "proprietary" links. 

(g) C.T.'s used to operate T.O.L.'s shall be protection type, saturating at 10 to 15 times 

MEW E101 Page 49


full load current, and shall comply with AS 1675, Class 10P. also refer to Clause 207.17. 

Note: Where used on fire-pump motors T.O.L.'s shall be used to indicate motor overload 

only. 

Thermistors 

Thermistors shall be installed in the motor winding as detailed in Clause 505. 

The thermistor protection relay shall be compatible with the thermistors installed in the 

motor and shall comply with AS 1023 Part 1. 

The relay shall have at least one (1) normally open and one (1) normally closed set of 

contacts rated at the starter control circuit voltage and minimum 4 A 240V ac AC 15. The 

contacts shall be connected to open the starter at the setting temperature. The control 

unit shall be of a type that does not reset following a power failure. 

The circuit shall be arranged so that failure of any thermistor by going very low resistance 

or open circuit or other component in the control system, or excessive winding 

temperature, results in the motor circuit being opened. In addition, on open, a circuit shall 

also trip. A manual reset device shall be provided to restore the motor circuit when 

tripped due to excessive winding temperature. 

A LED shall be installed on the thermistor control unit to indicate that the circuit is in 

normal operating mode. 

Electronic Motor Protection Relays 

Electronic motor protection relays shall incorporate the following features: 

(a) Single phasing protection and phase sequence protection. 

(b) Thermal overload protection. 

(c) Loss of load protection. 

(d) Excessive motor run-up and stall protection. 

(e) Earth fault protection. 

(f) LED indication of fault conditions. 

(g) Manual reset facilities. 

(h) Adjustable settings of protection parameters (items (b) to (e)). 

(i) One (1) normally open and one (1) normally closed set of auxiliary contacts with 

minimum current rating (I e ) of 4 A at 240 V a.c. AC 15. 

(j) C.T.'s used to operate these relays shall be protection type, saturating at 10 to 15 

times full load current complying with AS 1675 class 10P. The relay shall 

incorporate adjustment facilities to allow matching of C.T. characteristics. Also 

refer to Clause 207.17. 

(k) Test facilities shall be incorporated to allow testing of the relay. 

207.13.3 Single Phase Motor Protection 

Single phase motors required by AS 3000 to have overload protection shall be equipped 

with one of the following forms of overload protective devices: 

(a) Proprietary type integral overload units within the motor, sensing either motor 

winding temperature or motor current. Preference shall be given to overload units 

having manual reset facilities. 

Where motors incorporating integral overload units are installed in inaccessible 

positions, the overload devices shall be disconnected and, in lieu, one of the types 

referred to in (b) below shall be used. 

(b) Overload units generally meeting the requirements of Clause 207.13.1 with the 

three individual phase overload elements wired in series.. 

Page 50 MEW E101

207.14 Time Switches 

Time switches shall incorporate the following features: 

(a) Electronic with quartz crystal control. 


(b) Reserve power supply to operate time switch during mains supply failure shall have 

minimum capacity of 24 hours and battery reserves shall have minimum initial 

capacity of 100 hours and 10 year battery field life. 

(c) Displays shall be digital with liquid crystal. 

(d) Minimum 16 A AC-15, 140 V contacts. 

207.15 Hour Run Meters 

Hour run meters shall incorporate the following features: 

(a) Minimum six digits, indicating up to 99999.9 hours. 

(b) Digits shall be at least 3.5 high. 

(c) A running indicator. 

(d) Non reset type 

207.16 Indicating Counters 

Indicating counters, eg number of starts counters, shall incorporate the following features: 

(a) Minimum 6 digits. 

(b) Digits shall be at least 3.5 high. 

(c) Continuous duty 

(d) Non reset type. 

(e) Surge diverters shall be fitted. Diverters shall be varistors min 4500A 100 joule 

275 Volt. 

207.17 Extra-Low Voltage Transformers 

Transformers shall comply with AS 3126. 

The following features shall be incorporated: 

(a) The primary and secondary windings shall be brought out at opposite sides of the 

transformer case. 

(b) The primary and secondary windings shall be separated by means of an earthed 

screen: this screen shall be brought out to an insulated terminal where the 

transformer is installed in a double insulated situation. 

(c) The output loading shall not exceed 80% of the transformer continuous rating. 

Note that such rating shall take account of the degree of ventilation and ambient 

temperature of the transformer and supplied load. 

207.18 Current Transformers (CTS) 

(Not Applicable to Supply Authority Equipment or Protection CTS) 

Current transformers shall be resin encapsulated window type and shall comply with AS 

1675. 

The following details shall apply: 

(a) Rated primary current shall have a current rating equal to the maximum current 

rating of the frame size of the controlling device. 

(b) Secondary windings of measurement current transformers shall be rated at 5 A. 

The burden shall be 0.4 ohms (10 VA) minimum and the accuracy shall be class 2 

minimum. 

MEW E101 Page 51


(c) Secondary windings of protection current transformers shall be rated 5 A and shall 

be suitable for burden. 

Current transformers shall be capable of withstanding the indicated switchboard fault 

level for the appropriate time of duration and shall be suitable for operation in an ambient 

temperature of 30ºC with a temperature rise of 75ºC. 

Where fitted on busbar systems each C.T. shall be fitted on removable links to allow easy 

removal from the switchboard. 

Where fitted on cables C.T.'s shall be installed to allow easy removal from the 

switchboard. 

Where C.T.'s are associated with ammeters M.D.I.'s or energy meters, each C.T. shall be 

provided with test link terminals. 

207.19 Meters and Associated Controls (Not applicable to Supply Authority Equipment) 

207.19.1 Voltmeters, Ammeters, Maximum Demand Indicators and Associated Controls 

Meters shall comply with AS 1042 and the following details shall apply: 

(a) Flush mounting. 

(b) Accuracy class 1.5 (minimum). 

(c) Meter movements shall be jewel and pivot or taut band type, with oil damping. 

(d) Impact resisting anti-glare face. 

(e) Voltmeter transfer switches shall be seven position type with positions designated 

R-W/W-B/B-R/OFF/R-N/W-N/B-N and shall be mounted under or adjacent to the 

relevant voltmeter. Also refer to Clause 207.9.3. 

(f) Ammeter transfer switches shall be four position type with positions designated 

R/W/B/OFF and shall be mounted under or adjacent to the relevant ammeter. Also 

refer to Clause 207.9.3 

(g) Meters shall be minimum 72 square bezel with 90 degree quadrant scale. 

(h) Meter scales shall be direct reading. 

(i) Meters shall be mounted on hinged panels and wired with maximum 6mm 2 cable. 

Where associated exclusively with one phase, meters shall be labelled "RED", 

"WHITE" or "BLUE" as applicable. 

(j) Potential protection devices for meters shall be grouped together behind a cover or 

hinged door, preferably adjacent to the current transformer test links. 

(k) Ammeters subject to motor starting currents shall be overscaled a minimum of five 

times. 

(l) Meter scales shall be as indicated. Ammeter scales shall be selected such that 

running current is at 45° approx. 

(m) Maximum demand indicating meters shall have a 15 minute response time and 

provision for sealing of the reset mechanism. Where M.D.I. metering is indicated, 

a meter in each phase shall be provided. An accuracy of Class 3 is acceptable. 

207.19.2 Energy Meters 

These requirements shall apply to rotating element induction type meters designed to 

register kWh. Meters shall be general purpose type complying the AS 1284 Part 1. 

Where metering is on three phases a polyphase meter shall be used. For two or one 

phase metering single phase meters shall be used. 

Meters shall be selected to suit load and probable overload conditions. Whole current 

meters shall be 15 to 100 A current rating and meters supplied with current transformers 

shall be suitable for 5 A secondary. 

Page 52 MEW E101


Registers shall be large figure cyclometer type and shall be direct reading. 

Meters shall be supplied with calibration error figures and shall have the main cover 

sealed. Calibration error figures shall be supplied to the Superintendent together with 

relevant technical data and wiring diagrams. 

207.20 Indicating Lights 

Indicating lights shall be of the oil-tight type with heat resistant plastic or glass lens. Size 

classification shall be uniformly D30 or D22. 

Lamps shall be maximum 28 V incandescent type supplied from integral or separate 

transformer and shall be suitable for the indicating light used with maximum rating of 1.2 

W. Higher voltage globes shall be used where available e.g. 28 V globes for 24V. 

Lamps shall be changed from front of switchboard and lampholders shall remain rigidly 

fixed in panel during lamp changing. 

Lamps shall not become disconnected under conditions of vibration. 

Three (3) spare lamps per 10 indicating lights or part thereof and tools for removal of 

lamps (if applicable) shall be provided. 

Indicating light colours shall comply with AS 1431 Part 2, Table 5.3.1 (A) "Colours of 

indicating lights and their meanings" or as per the drawings. 

207.21 Variable Speed Drives 

The following clause applies to VSDs controlling 415V, 3 phase, squirrel cage induction 

motors: 

The adjustable speed electrical power drive system (PDS) shall comply with AS61800.3 

and shall comply with intended use sub clause 3.2.2 (second environment) and sub 

clause 3.2.5 (PSS of Category C3). Compliance with Australian EMC Framework C Tick 

is also required. 

The VSD shall be suitable to drive its associated motor throughout its entire speed range 

under all conditions of operation to achieve: 

• Continuous and smooth operation through all speeds 

• Torque speed curves which rise continuously with increasing speed with variable 

torque which increases with increasing speed and flat torque speed curves for 

constant torque loads 

• Correct operating and commutation characteristics 

• Minimum ripple current, motor heating and noise generation 

• Correct running and starting sequences 

• Ability to operate on a 3 phase input voltage of 415 V a.c. with prolonged periods 

of 440 V a.c. 

• Suitable for 3 phase, 415 V a.c. motors of the ratings specified in the contract 

documentation 

• Minimum a.c. network harmonic distortion within the limits required by the 

Electricity Supply Authority or as specified in AS 61000, whichever is the more 

onerous. As well, the maximum level of total harmonic current distortion shall be 

no greater than 5%. 

. 

One VSD unit shall be dedicated to each variable speed driven motor. 

Cabling for VSDs 

Control cables shall be shielded/armoured with the shield connected by means of a cable 

clamp at both ends to the metal enclosure. 

MEW E101 Page 53


Control cables and the filtered line cable shall be installed separately to the motor cables 

at a distance of separation as large as possible and in accordance with the 

manufacturer’s recommendations. 

Motor cabling specifically designed to suit the requirements of the variable speed drive 

shall be used. Such cables shall have features which reduce the transmission of 

electromagnetic interference. 

Air Conditioning 

Where installed outdoors, switchboards containing VSDs shall have one suitable air 

conditioning unit per VSD. 

Where installed indoors, the room containing the VSD(s) shall be suitably air conditioned. 

The level of air conditioning shall be such that the temperature at the VSD does not 

exceed the maximum allowable operating temperature of the VSD minus 5 degrees 

Celsius. 

Starting Limitations 

Each speed controller shall be capable of starting its motor from rest for all speed 

settings without exceeding a supply current of twice full load current of the motor and 

shall be able to achieve this starting current without falsely tripping or operating any 

protective device or overheating the motor. 

Motor Insulation Considerations 

When selecting the VSD, protection against damage to the motor windings and bearings 

shall be provided to meet the recommendations of IEC 60034:17 for limiting the 

maximum peak voltage and the rise time at the motor for up to 150 metres of screened 

cable. The use of soft switching of the insulated gate bipolar transistor or provision of 

output filters to limit the peak voltages is acceptable. 

Additional Filters 

Where indicated in the documentation, make provision for advanced harmonic filters and 

wave filters to ensure. Filtering equipment shall meet the manufacturer’s 

recommendations for the application. 

Single Phase Fault Response 

The VSD shall be capable of “Autoderating” when losing a single mains phase and 

recover upon the restoration from the single phase fault. Hence, the VSD shall neither trip 

nor require to restart upon a temporary single phase fault. 

Power Supply 

Each speed controller shall be suitable for operation from a 415V, 3 phase, 4 wire, 50 Hz 

supply having a prospective fault level of at least 50kA as far as thermal and magnetic 

overcurrent effects are concerned and a voltage tolerance of plus or minus 10% and 

rating to suit the motor and drive selected. 

Efficiency 

The speed controller will be required to control the speed of the unit within close tolerance 

of speed setting with maximum efficiency. The V/F output curve of the VSD shall match 

the V/F profile that the load curve of the driven mechanical item requires. This is, the load 

curve of the driven item shall be matched by an adjustable V/F output curve of the VSD, 

in order to save energy that would be wasted if the V/F ratio of the voltage output of the 

VSD and the V/F profile that the load curve of the driven mechanical item requires are 

different. 

Accuracies 

The speed controllers shall be designed such that the drive speed is independent of load 

conditions, motor iron losses and fluctuations in supply voltages and frequency in order to 

give good speed stability and accurate speed control with motor current limited to a safe 

Page 54 MEW E101


level for all speeds. The speed shall be controlled to within plus or minus 2.5% of input 

speed for a range of 10% to 100% speed. 

Harmonics 

Generated harmonics shall be limited to one third of the limits set down in AS 61000 and 

as required by the Supply Authority through appropriate design of equipment and any 

devices necessary to achieve this, such as capacitors and/or inductors. For the purpose 

of the design of the harmonic filter components, use the current actual fault level of the 

installation. For the purpose of thermal and magnetic ratings against fault overcurrents, 

assume a fault level rating of 50kA unless otherwise specified in the documentation. 

Care shall be taken in the harmonic filter design to ensure that there is no interference 

which may cause malfunction with other electronic equipment in the switchboard. 

The maximum total harmonic current distortion shall be 5% or less. Filters shall not cause 

power system resonance nor attract harmonics from other non linear loads. Filters shall 

meet the requirements of IEEE-519. 

As an alternative to providing dedicated harmonic filters for all drives, filtering can be 

provided such that the whole of the installation meets the requirements of the Supply 

Authority, AS61000 and the limitation of total harmonic current distortion of less than 5%. 

Status and Faults 

Provide the following fault indication with reset provisions for each fault: 

• Earth fault in motor 

• Input undervoltage fault 

• Input overvoltage fault 

• Over temperature fault 

• Output overcurrent 

• Regeneration overcurrent 

Provide the following status: 

• Remote Trip 

• Power on 

• Unit enabled 

• Acceleration limit operating 

• Deceleration limit operating 

• Unit at zero speed 

VSDs shall be able to drive a 0-5/10 Vdc meter with a voltage signal which shall be 

linearly proportional to load motor frequency. 

Programming Aspects 

It shall be possible to upload/download to copy the set up program from one VSD to 

another. Provide an operating keypad on each VSD which is detachable so as to provide 

upload/download functionality which allows the copying of one set up program from one 

VSD to another. 

Electromagnetic Interference 

Electromagnetic interference emitted by the equipment shall be within the limits stipulated 

by AS 61800.3. Provide RFI filters for each of the motor drives. 

Converter Stage 

The converter stage shall include a full wave bridge rectifier and any required line side 

short circuit protection. The converter stage shall also include all supply line voltage surge 

MEW E101 Page 55


filtering, RFI filtering and line side harmonic filtering. For converter stages which comprise 

controlled rectifier bridges include all required auxiliary control equipment and firmware. 

DC Link Stage 

The DC link stage shall comprise all control and monitoring devices required to establish 

DC voltage and current conditions applicable to the type of inverter used. 

Inverter Stage 

The inverter stage shall provide dc to ac inversion at the voltage and frequency 

appropriate to the speed setting. All control and monitoring including capacitors, inductors 

and components required by the methods of modulation and commutation shall be 

included. The inverter stage shall include the motor protection and monitoring devices 

including thermal overload and thermistor relays. 

The converter, link and inverter stages shall incorporate protection devices and circuitry 

to ensure maximum reliability under all operating conditions. 

Degree of Protection 

For stand alone enclosures, the degree of protection shall be IP51. 

Single Phase VSDs 

Single phase VSDs providing a three phase output are permitted up to a maximum size 

motor of 0.37kW. 

207.22 Audible Alarm Devices 

207.23 Terminals 

207.24 Locking 

Audible devices such as buzzers, small bells or electronic alarms shall be suitable for the 

application. Where several different alarms are included in one location and where 

distinction between alarms is required immediately, different tones or devices shall be 

used. 

Terminals shall be screw tightened, clip-on, 32 DIN rail mounted, flexible, non-flammable 

and, as a minimum, suitable for the insertion of blade of a screwdriver width 3mm. The 

cable shall be secured by a moving plate actuated by the screw. Direct contact of the 

screw to the wire is not permitted. 

For up to cable size 70mm ² , terminals shall be from the same manufacturer and shall be 

capable of accepting the indicated cable size plus a minimum of 10%. 

Above 70mm ² cable size, terminals shall be of the stud type fixed to the switchboard (not 

rail mounted). 

Terminals shall be located such as to provide easy access to outgoing terminations, with 

cable holes clearly visible. 

Mounting rails shall be riveted or screwed to the switchboard at not more than 500 

centres and shall be of sufficient length to accept a further 20% terminals or 3 terminals, 

whichever is the greater. For each type of control terminal, install on the mounting rail 

10% spare terminals or 3 terminals, whichever is the greater. 

Terminal rails may be used as earthing conductors only if they are aluminium and earthed 

separately to the main earth. Maximum rating of rail shall be 80A. 

Where lockable doors are indicated, locks shall be "keyalike" "E" type DPWS, or 

approved alternative. 

Two keys shall be provided for each switchboard. 

Lock handles and surrounds shall be nickel or chromium plated. 

207.25 Ambient Temperature 

Page 56 MEW E101


All outdoor SCA equipment shall be rated for an external air temperature of 45°C. All 

indoor SCA equipment shall be rated for an external air temperature of 40°C. 

Relative humidity shall be 0-90% non-condensing. 

MEW E101 Page 57


208 SWITCHBOARD CONSTRUCTION 


For Proprietary Assemblies, manufacturer's standard construction may be accepted. 

Cubicles shall be sized to suite the location and purpose and shall be fitted with 

removable access covers. 

The arrangement of equipment within each section shall be such as to allow easy access, 

maintenance and, where applicable, adjustment. All terminations shall be visible from the 

front, or the rear of the cubicle for rear access switchboards. 

Internal equipment shall be mounted on equipment mounting panels. 

Suitable supports (e.g. cable trays or adequate support straps) shall be provided within 

switchboards for all external cabling. As far as practicable such supports shall be located 

along the entire cable route length. 

Adequate space shall be provided within each switchboard to accommodate all cables 

and cable terminations. 

Cables gland plates shall be fitted from within the cubicle with adequate room for access 

to the plates. Plate shall be 5mm thick aluminium. 

Switchboards mounted externally shall not be provided with top cable entries. 

To prevent the ingress of dust, ventilation louvres shall not be provided unless required to 

cool heat developing equipment such as ballasts and transformers. If ventilation louvres 

are fitted they shall be metal screened to minimise vermin entry and maintain the IP 

rating. 

Wall mounted switchboards shall be provided with an adequate number of M10 clearance 

fixing holes. However, not less than four fixings per switchboard shall be provided. The 

holes shall be clear of all switchboard equipment, readily visible and accessible from the 

front with the switchboard covers removed. All wall mounting switchboards shall contain 

additional internal reinforcing to prevent distortion of the cubicle after mounting and 

through which the fixing bolts shall pass. 

Floor mounted switchboards shall be mounted on a full perimeter minimum 75 high x 40 

wide x 6 thick mild steel channel base. The base shall be drilled with at least four M12 

clearance holes per channel base section to allow fixing of the switchboard to the floor. 

Fixing holes shall be positioned to allow easy access to all floor mounting bolts. 

Additionally, the base shall be hot dipped galvanised to AS 1650 to a minimum thickness 

of 85 micrometres and shall not be painted. As an alternative to using fixing holes and 

bolts floor mounted switchboards may be clamped in position using suitable galvanised 

clamps internal to the switchboard. 

Mechanical equipment containing fluids or steam such as pressure gauges, pressure 

switches, etc., shall not be installed in these switchboards. In the case of pneumatic 

controls they shall be located generally in a separate panel except when of a minor 

nature. 

208.2 Externally Mounted Switchboards 

Externally mounted switchboards shall have a minimum degree or protection IP 56. 

If the externally mounted switchboard contains a variable speed drive unit, air 

conditioning of the outdoor switchboard shall be provided. 

Switchboards, with an overall volume 1m³ shall be fitted with ventilation louvres located at 

the top and bottom of the vertical surfaces and which maintain the IP ratings. 

Openings in the enclosure shall be flanged to prevent the entry of water running down the 

vertical surfaces when any cover or door is open. Drain holes shall be provided in the 

bottom of the enclosure and shall be metal screened to minimise vermin entry and to 

maintain the IP rating. 

Page 58 MEW E101


Where an outer roof is indicated, it shall be spaced from the top of the enclosure by a 

ventilated air space. The outer roof shall overhang the enclosure by 50 on all sides, shall 

have a minimum pitch of 5° away from all openings a nd shall be provided with a gutter at 

all openings. 

The top of the enclosure, or the outer roof where fitted, shall be free of openings, bolts, 

rivets or other penetrations and shall have sufficient strength to support a person without 

distortion. 

Thermostatically controlled anti-condensation heaters shall be fitted to weatherproof 

switchboards with an external surface area in access of 4m², and shall be on the basis of 

10 watts/m² of exposed surface area. 

Anti-condensation heaters shall be of the black heat type, shall be able to be touched 

without harm and shall be mechanically protected. 

208.3 General Cubicle Construction 

Cubicles, covers and doors shall be manufactured from zinc coated sheet steel not less 

than 1.5 thick except for exterior surfaces of weatherproof switchboards where marine 

grade sheet aluminium not less than 2.0 thick shall be used. Marine grade sheet 

aluminium shall be grade "5251 H34" with finish "MILL". 

Panels forming the body of the cubicle shall be straight and of sufficient rigidity to prevent 

warping and excessive flexing with or without covers and doors fitted. 

Cubicles shall be all-welded construction, with sheets bent to minimise the number of 

welded joints. Consideration will be given to non-welded forms of construction but written 

acceptance shall be obtained from the Superintendent before manufacture. 

Edges shall be rounded to remove sharp or irregular projections, etc. 

Internal equipment panel supports shall be heavy metal angles or plates bolted or welded 

to the cubicle sides. 

For earth continuity, serrated washers shall be placed under bolt heads and nuts of all 

painted, structural metal-to-metal contact points. 

Equipment mounting panels shall be minimum 2.6 thick and equipment shall be mounted 

by studs brazed to the panel or be set screws into proprietary threaded inserts. 

Alternatively, small items (e.g. relays) may be set screw fixed into tapped holes in the 

panel. Mounting of equipment panels shall be by minimum M6 plated steel screws. 

All metal in contact shall be as close as possible on the electrochemical series to 

minimise corrosion due to dissimilar metals in contact. 

208.4 Construction of Covers and Doors 

Covers and doors shall be manufactured with right angle welded corners, shall be straight 

and of sufficient rigidity to prevent warping and flexing when fitted to, or removed from, 

cubicle. 

The construction of covers and doors shall allow easy removal and replacement. 

Covers shall fit neatly to expose only the toggles and escutcheons of flush mounted 

equipment, but shall allow interchangeability of 1, 2 and 3 pole circuit breakers. All 

covers and doors shall be fitted with neoprene seals around openings for breakers. 

The minimum requirement for doors and covers shall be a single right angle return on all 

four sides, with adhesive U-section sealing rubber or other accepted means to prevent 

paint damage. 

For Custom-built Assemblies the seal shall be a neoprene section. Foam rubber shall 

not be used. The surfaces involved in forming the seal shall be at least as wide as the 

sealing strip, a minimum of 12, and the seal shall be effectively retained in a U-channel 

section. 

MEW E101 Page 59


Each cover shall have a minimum of four fixings, each consisting of an M8 plated stud 

fixed to the cubicle and fitted with a serrated star washer and a nickel or chromium plated 

acorn nut. 

All edges of all covers shall rest on the cubicle body or on a mullion. Interlocked covers 

are not acceptable. 

All covers shall be fitted with chromium plated "D" type handles. 

Doors shall be fitted with chromium plated pintle hinges, and doors above 1m in height 

shall have three hinges. Doors which are removable shall have staggered pin lengths to 

achieve progressive engagement as the door is fitted. Non lift-off doors shall have the 

hinges opposed and shall be fitted with a restraining device to prevent damage to 

adjacent surfaces or equipment. 

The arrangement of door mounted equipment shall allow for ease or operation. All 

equipment and terminals on the inside of doors shall be shrouded or otherwise protected 

to prevent inadvertent contact with live terminals and/or wiring. An insulated panel 

covering the equipment is an acceptable method. 

Doors shall have a maximum width of 900, be hinged on a vertical side and be fitted with 

a stay to hold the door open at minimum angle of 120 o . 

208.5 Spacing and Mounting of Circuit Breakers 


Circuit breakers shall be mounted in a regular and logical manner with the toggles 

operating in either the vertical or the horizontal plane. When operating vertically the "on" 

position shall be uppermost. 

Circuit breakers with interchangeable trip units shall be connected so that the trip units 

are not "live" when the circuit breaker contacts are open. 

208.5.2 Circuit Breakers Not Larger than 160 Amps 

Adequate and unimpeded space for access to external cabling is required around multipole 

proprietary busbar assemblies in switchboards. Clearances shall be measured from 

the return edges or folds of the cubicle to the busbars or circuit breakers, whichever is the 

lesser. The following are minimum requirements. 

(a) On all sides of a busbar assembly a clearance of 100 shall be provided, except 

(b) where a switchboard compartment contains a total of more than 60 poles, a 

clearance of 150 on all sides of a busbar assembly shall be provided. 

208.5.3 Circuit Breakers Larger than 160 Amps 

Adequate uninterrupted internal air space shall be provided for the natural convection 

cooling of all circuit breakers. 

The volume of the total possible number of circuit breakers shall not exceed 25% of the 

volume of the compartment, unless verification in the form of an approved Testing 

Authority Test Report is available proving that circuit breakers can successfully operate at 

full load under more compact arrangements. 

208.5.4 Circuit Breakers of the Drawout Type 

Each circuit breaker shall be housed in an individual compartment in accordance with the 

manufacturer's recommendations. 

208.6 Spacing and Mounting of Fuse Combination Units 

FCU's shall be arranged in a regular and logical manner and connected such that the 

fuse links are isolated when the switch contacts are open. 

Page 60 MEW E101


The extended operating handle of an FCU shall, in any position, remain clear of all other 

equipment and be not less than 100 from the floor. 

208.7 Space for Future Circuit Breakers and Fuse Combination Units 

Where space is provided for future circuit breakers and FCU's the switchboard shall be 

fitted with the necessary holes, connection studs and busbar connections to allow 

installation and connection. 

Front covers shall have all necessary cut-outs for the future equipment and individual or 

proprietary blanking plates shall be fitted. Blanking plates shall be installed such that 

when removed and the equipment fitted, no unused holes are visible. Fixing of blanking 

plates by adhesive material is not acceptable. 

208.8 Mounting Heights 

(a) No equipment or cable termination, other than neutral and earth links, shall be 

mounted less than 200 from floor level. 

(b) Mounting heights above floor level of fuse links and toggles of circuit breakers and 

fuse combination units shall be between: 

(i) 300 and 2000 for Custom-built Assemblies Type “CT” and ”CU” 

(ii) 200 and 2000 for Custom-built Assemblies Type “DT”,“DU”,“DUPLUS”& 

“DTPLUS”. 

(c) Mounting heights above floor level for control switches, indicating lights, meters 

and other equipment requiring operator interface or viewing shall be between: 

208.9 Extra Low Voltage 

(i) 300 and 1700 for Custom-built Assemblies Type “CT” and “CU” 

(ii) 200 and 1800 for Custom-built Assemblies Type “DT”,“DU”,“DUPLUS”& 

“DTPLUS”. 

Extra-low voltage control circuits shall preferably be 24 volts a.c. or 24 volts d.c. 

208.10 Auto-transformer Compartment 

Each auto-transformer of an auto-transformer motor starter shall be located in a separate 

ventilated compartment segregated from the remainder of the switchboard cubicle by 

steel partitions. This separate compartment may have a minimum degree of protection 

IP 41. 

208.11 Arrangement of Equipment 

(a) Switch/control gear shall be mounted on horizontal combination rail and shall be 

set out in a logical manner in functional groups which shall be separated by cable 

ducts or an equivalent space. 

The following minimum requirements shall apply: 

180mm centre to centres spacing between rows of equipment. 

(b) All internal cabling shall be run in slotted ducts. 

(c) Readily accessible terminals grouped in conventional locations shall be provided 

for the connection of all external control cables and out-going power circuit cables. 

These terminals shall be labelled to correspond to the identification shown on 

switchboard workshop drawings. 

(d) Control switches, indicating lights, meters and other equipment requiring operator 

interface or viewing shall be set out in a logical manner in functional groups and 

shall be able to be accessible without the use of a key (to be able to be operated). 

MEW E101 Page 61


209 PAINTING OF SWITCHBOARDS 


Proprietary assemblies shall be painted in accordance with the manufacturer’s standard 

except that the external colour of the assembly shall be orange X15 and the internal 

colour and escutcheon colour shall be off white Y35. 

All metal surfaces of the switchboard cubicle and covers shall be painted. Stainless 

steel, electroplated, anodised or galvanised equipment mounting panels need not be 

painted. 

Insulating materials, and door and cover sealing strips shall not be painted. 

209.2 Paint Materials 

All paint and other preparations shall be of the best quality, non-poisonous, lead-free 

synthetic products, conforming to the relevant Australian Standards. Paint materials shall 

be used strictly in accordance with the manufacturer's recommendations. 

209.3 Surface Preparation 

Where the protective coating of any steel surface is removed through welding, grinding, 

etc., the standard of surface preparation shall be to AS 1627 with minimum power tool 

clean to grade "St 3", followed by the application of a cold galvanising compound. 

Surfaces shall be degreased using solvent or alkaline solutions. 

209.4 Painting and Finish 

One coat of etch primer having a suitable corrosion inhibiting compound shall be applied. 

If required, a putty sealer, rubbed back to cover major imperfections, and undercoats 

rubbed back to cover minor imperfections shall be applied. Undercoats shall be applied 

as a base for the final coats unless otherwise recommended by the paint manufacturer. 

The finish shall be full-gloss heat cured enamel or 2-pack polyurethane paint which shall 

be applied on internal and external surfaces in accordance with the manufacturer's 

recommendations to achieve a completely smooth finish with no noticeable 

imperfections. Minor paint surface ripple due to the use of galvanised sheet steel will be 

accepted. 

The minimum thickness of the finished paint coating shall be 60 micrometres for indoor 

switchboards and 90 micrometres for weatherproof switchboards. 

Minimum pencil lead hardness factor shall be "H" to AS 1580 (method 405.1). 

Switchboard colours shall comply with AS 2700 and shall be: 

(a) Indoor switchboards - X15 orange 

(b) Weatherproof switchboards - G52 eucalyptus 

(c) Removable equipment panels - Y35 off white 

210 LABELLING OF SWITCHBOARDS 


Every switchboard, switchboard control, contactor, time switch, relay, indicator lamp, 

meter, motor starter, link and any control or protection equipment within or on a 

switchboard shall be clearly and accurately labelled under the equipment. 

Labels shall be engraved laminated plastic and shall comply with the following 

requirements:- 

Except where otherwise required, labels shall not be on any item of equipment. 

Page 62 MEW E101


Exterior labels associated with door mounted components (eg. indicating lights) shall be 

mounted directly beneath that equipment. In addition, circuit reference labels shall be 

fixed on the inside of the door adjacent to the equipment. 

Engraved lettering shall be black on a white background, except that the label for a main 

switch shall have red lettering on a white background, and warning and caution labels 

shall have white lettering on a red background. 

The minimum height of lettering shall be 3 and of sufficient definition to allow easy 

reading. 

210.2 Fixing of Labels 

Labels shall be securely fixed by: 

(a) Screws and adhesive, or 

(b) Fixed in an extruded aluminium section which shall be countersunk screw fixed or 

countersunk riveted to the panel. 

(c) Plastic drive pin and adhesive. 

Screws shall be tightened with nuts or into tapped holes in the switchboard. Mechanically 

expanded plastic rivets of minimum 6 head diameter are acceptable instead of screws. 

Aluminium or monel rivets may be used to fix aluminium labels only. Self-tapping screws, 

thread-cutting screws or other fixing are not acceptable. 

210.3 Labels on Exterior of Switchboards and Schedules 

All switchboards shall be labelled with the manufacturer's name and the manufacturer’s 

type designation or identification number or other means of identification making it 

possible to obtain relevant information from the manufacturer. 

Custom-built Assemblies shall be provided with a name plate containing the following 

minimum data to AS/NZS 3439.1:2002: 

• The manufacturer’s name 

• The manufacturer’s type designation or identification number 

• Rated Operational Voltages 

• Rated Main Busbar Current 

• Rated short-time withstand current of the Main Busbars 

• Short-circuit withstand strength of the Assembly (see 7.5.2 of AS/NZS 

3439.1:2002) 

• Degree of Protection 

• Form of Separation 

• This document’s classification of the switchboard 

(eg. “NSW Dept of Commerce - MEW E101-Custom-built Type “DT” ” ) 

A switchboard designation label shall be provided (eg. “West Haven Sewage Pumping 

Station No. 3 - Main Switchboard”). For other than main switchboards, the designation 

label shall also state the source of electrical supply. Separate sections of enclosures 

shall be identified. The label for any section or enclosure containing Supply Authority 

equipment shall be to the satisfaction of the Superintendent and the Supply Authority. 

Every switchboard control shall be labelled and shall include:- 

(a) Circuit designation for all main switches, main controls and submain controls. 

(b) Details of consumers mains and all submains. 

(c) Incoming busbar or cable rating to the first tee-off. 

(d) Fuse link size fitted to each FCU. 

MEW E101 Page 63


For uniformity, the labels shall agree with the following examples and be of the minimum 

lettering height shown: 

ITEM ENGRAVING EXAMPLE MINIMUM HEIGHT 

Main Switchboard MAIN SWITCHBOARD 10 

Distribution Board DISTRIBUTION BOARD 3 

8 

(SUPPLIED FROM MSB) 

3 

Main Control on a Main 

Switchboard 

MAIN SWITCH 6 

Submain Control SUBMAIN CONTROL TO DB 3 3 

Main Control on a 

Distribution Board 

LOCAL MAIN SWITCH 6 

Control for Section of MAIN CONTROL 

6 

Switchboard 

SECTION NAME 

3 

ELCB Control for Section MAIN CONTROL 

6 

of Switchboard 

ELCB PROTECTED 

CIRCUITS 

3 

SECTION NAME 

3 

Copper Cu 3 

Aluminium 

Cable Designation 

Al 

8 x 1 CORE 150mm 

3 

² Cu 

PVC/PVC 

3 

Incoming Busbar (or INCOMING BUSBAR (or 

3 

Cable) Rating 

CABLE) TO FIRST TEE-OFF: 

800A 

Fault Current Limiters FAULT CURRENT LIMITERS 

3 

behind cover 

BEHIND 

F.C.U. Fuse Link Size 160A FUSES 3 

Spare Parts Section SPARE FUSES/PARTS 

BEHIND 

6 

Phases RED, WHITE & BLUE 3 

For identification of final subcircuits, a typed schedule, cross-referenced to the lighting 

and power layout plans, shall be provided. The schedule shall be protected by a plastic 

sheet and fixed in a suitable frame mounted on the inside of the relevant switchboard 

door of, if the switchboard has no door, on the wall immediately adjacent to the 

switchboard. Refer to Clauses 114.5 and 214. 

210.4 Labels on Interior of Switchboards 

Labels identifying equipment within a switchboard shall be located such that the item 

referred to is obvious and the lettering is not substantially obscured by the temporary or 

permanent position of any equipment or wiring. 

For plug-in equipment where items are physically but not functionally interchangeable, the 

label wording shall be expanded to clearly identify the removable section (e.g. to identify 

the contact configuration or timing range). Where this is not possible, a second 

identifying label shall be glue fixed to the removable section. 

The function and coding shown on the circuit diagram shall be used. 

The MEN link shall be labelled or stamped and infilled MEN LINK on the link. 

Labels for fault current limiters shall indicate the rating of the fuse links fitted, for 

example: 

FAULT CURRENT LIMITERS 160A. 

210.5 Warning Labels 

Where copolymer membrane coating is used anywhere on live conductors without further 

insulation, a warning label shall be provided on the front cover near the main switch or 

Page 64 MEW E101


local main switch and in a prominent position within each section of the switchboard. The 

label shall have the following wording in 6 high lettering: 

WARNING 

PAINTED COATING ON BUSBARS OR 

TERMINATIONS IS NOT INSULATION 

In each section of a switchboard containing fault current limiters, a warning label as 

follows shall be fixed adjacent to the fault current limiters: 

WARNING 

DO NOT REPLACE FAULT CURRENT LIMITERS UNTIL 

SOURCE OF FAULT HAS BEEN CLEARED, REPLACE ONLY 

WITH IDENTICALLY RATED FUSE CARTRIDGES 

Should any item of equipment on a switchboard not be isolated by the main switch or 

local main switch (eg a relay fed from another switchboard) a warning label shall be 

provided adjacent to the equipment. An example of a suitable label is: 

WARNING 

ORANGE WIRING IS NOT CONTROLLED BY THE 

MAIN SWITCH ON THIS SWITCHBOARD 

If a stand-by power supply is installed, an appropriate warning label shall be fixed at the 

main switch or local main switch. An example of a typical label is: 

WARNING 

IN THE EVENT OF LOSS OF NORMAL SUPPLY 

A.C. GENERATOR SET WILL AUTOMATICALLY START 

AND BE CONNECTED TO THIS SWITCHBOARD 

When anti-condensation heaters are fitted, a label shall be provided at each heater 

reading: 

WARNING 

THERMOSTATICALLY CONTROLLED ANTI-CONDENSATION 

HEATER - DO NOT SWITCH OFF 

210.6 Special Label on Custom-built Assemblies 

Where the removal and non-replacement of any insulation or shrouding during normal 

switchboard maintenance could lead to the possibility of arcing faults, a label with 

appropriate wording shall be provided for each function unit. An example of a suitable 

label is: 

WARNING 

REPLACE LINE SIDE SHROUDS AND INSULATING 

MATERIAL BEFORE REACTIVATING 

These labels shall be positioned to be readily seen, adjacent to, or in impracticable, on 

the busbar chamber covers of functional units, and also behind the front cover of 

functional units. 

A circuit identification label shall be provided in the cabling chamber of each functional 

unit. This label shall be positioned adjacent to the external terminations. 

MEW E101 Page 65


211 INSPECTION AND TESTING 


211.2 Inspection 

The following clauses refer to inspection and testing which shall be performed in the 

factory or on site, as indicated. Final inspection and testing will be carried out on site. 

The provision of all required testing apparatus shall be the responsibility of the 

Contractor. 

Witnessing of any or all tests will require ten working day minimum notice of all tests. 

Normally Serial "A" and "B" switchboards will be inspected on site. If indicated, a factory 

inspection of fully assembled switchboards will be carried out at the place of manufacture. 

Inspection of fully assembled Custom-built Assemblies will be carried out at the place of 

manufacture. 

Ten working days minimum notice shall be given for a factory inspection. 

211.3 Residual Current Equipment Testing 

A functional check of residual current equipment on completed switchboards shall be 

performed before delivery to site. Suitable testing apparatus shall be used which, as a 

minimum, shall consist of an adjustable resistance and a.c. millimetre to produce an out 

of balance current adjustable between 5 mA and 40 mA through the toroid. 

211.4 Dielectric Tests 

The dielectric tests described in AS/NZS 3439.1:2002 shall be performed at the factory 

or, if indicated, on site, except that the duration of the application of the test voltage shall 

be 60 seconds. A verification of insulation resistance test in accordance with clause 8.3.4 

of AS 3439.1:2002 shall be carried out before and after the dielectric test. The resistance 

shall be recorded. The tests shall be carried out between all live parts and the frame of 

the SCA and also between each pole and all other poles connected to the frame of the 

SCA. For the tests, either close all switching devices or apply the tests successively to all 

parts of the circuit. Any equipment which is not rated to withstand the tests shall be 

nominated by the tester and either disconnected or otherwise protected during testing. 

With Proprietary Assemblies a 1 kV d.c. test is required and for Custom-built Assemblies 

both 1 kV d.c. and 2 kV r.m.s. a.c. tests are required. 

Tests shall be conducted with all functional unit isolators switched "on". Special care 

must be taken to isolate equipment which could be damaged during the tests. 

211.5 Functional Testing 

Prior to delivery to a site a check of all switchboard equipment shall be performed. This 

check shall include the manual operation of all switches, circuit breakers, F.C.U.'s, 

contactors etc. 

Following the above check, functional testing shall be performed to ensure satisfactory 

operation of all interlocking, control protection and alarms. Where necessary, appropriate 

input and output devices shall be used to simulate external circuit conditions. 

211.6 Checking of Safety Measures and Electrical Continuity of Earthing Circuit 

Prior to delivery to site all safety measures against direct and indirect contact with live 

parts shall be checked and the earthing circuit shall be checked for compliance with 

requirements of AS/NZS 3439.1:2002. 

Page 66 MEW E101

212 DRAWINGS 



Each drawing shall have a discrete number. Resubmitted drawings shall be identified by 

a different suffix added to the drawing number for each re-submission, and a dated 

notation shall appear on the drawing indicating all changes which were made for each resubmission. 

All abbreviations shall be in accordance with AS 1000. 

Drawings shall conform to AS 1100 Drawing Practice, SAA HB7-1993-1989 Engineering 

Drawing Handbook, AS 1102 Graphical Symbols for Electrotechnology and AS 1103 

Diagrams, Charts and Tables for Electro-technology and AS3702-1989. Printing shall be 

minimum 2.5 high. Drawings shall be prepared on ISO standard drawing sheets size A1 

or A3. 

For Proprietary Assemblies, details may be submitted in the form of drawings, 

engineering schedules and/or correspondence each quoting numbers and issue 

identification of endorsed standard drawings. 

In the case of Custom-built Assemblies, all information shall be on a drawing. Equipment 

schedules shall be in drawing form. 

Proprietary Assembly drawings shall be on sheets separate from Custom-built Assembly 

drawings. 

212.2 Switchboard Drawings and Equipment Schedules 

Drawings and equipment schedules shall be submitted containing the following 

information: 

(a) Manufacturer's name, address, postcode and telephone number with STD code. 

(b) Switchboard designation (e.g. Main Switchboard) and classification (e.g. Custombuilt 

Type “CU”). 

(c) Indicated input fault level. 

(d) Overall dimensions of the switchboard and any separate enclosures (e.g. cable 

termination enclosure). 

(e) If surface or flush mounted. 

(f) If a door is fitted, and if so the hinge side of the door. 

(g) Confirmation of external paint colour. 

(h) Quantities and full details of all equipment, i.e. brand names and full catalogue 

numbers of equipment associated with each individual circuit and drive. 

(i) Proprietary circuit breaker busbar manufacturer's name, number of poles and 

continuous current rating. 

(j) Nameplate data (as per 210.3) 

212.3 Additional Information on Custom-built Assembly Drawings 

The following shall be shown in addition to that required by Clause 212.2: 

(a) An overall line diagram and circuit diagrams of main, auxiliary circuits, starters and 

control showing wire numbers, terminals, terminal numbers and all equipment. 

(b) One complete general arrangement and wiring diagram for each different 

switchboard. Typical diagrams and cross-references are not acceptable unless 

switchboards are identical. 

(c) Full details and sizes of the consumers mains and submains, and termination 

routes of these within the switchboard by means of dashed line. 

MEW E101 Page 67


(d) Spacing between proprietary circuit breaker busbar assembles and spacing 

between these assemblies, the switchboard cubicle and other equipment, either to 

scale or by dimensioning. 

(e) Proposed numbering of all circuit breakers, F.C.U.'s and the associated neutral 

and earth links. 

(f) The trip or fuse rating of circuit breakers and F.C.U.'s, together with the actual 

frame ratings derated due to duty or physical arrangement (e.g. 100A fuse/130A 

frame). 

(g) Details of all busbar and internal interconnecting cable sizes, spacing and 

configuration. 

(h) Details of busbar supports including materials, sizes, spacing and fixing methods. 

(i) Details of all internal segregations. 

(j) Clearance dimensions between the switchboard surfaces and permanent 

obstructions including the walls, ceiling and floor. Doors and hinged covers shall 

be shown in the open position and withdrawable equipment shall be shown racked 

out. 

212.4 Drawings Produced by Modification of Exhibited Drawings 

(Exhibited drawings are defined to be drawings which are part of the original 

documentation.) 

Drawings which are produced by modification of exhibited drawings shall be based on a 

clean print of the exhibited drawing which shall contain modifications and additions neatly 

marked up in red pen. These marked up drawings shall be signed by the contractor. Five 

copies of these drawings shall be supplied. 

212.5 New Drawings Submitted by the Contractor 

Where new drawings are required to be produced as part of this contract to supplement 

the modified exhibited drawings, produce the drawings using the latest versions 

Computer Aided Drafting software and print the drawings using a laser quality printer of 

minimum resolution 1200 x 1200 dots per inch. Use minimum 80 grams per square metre 

paper. Five prints of these drawings shall be supplied. 

213 OPERATION AND MAINTENANCE INSTRUCTIONS MANUALS 

Where indicated, Operation and maintenance instructions manuals shall be supplied with 

the switchboard. 

Each copy shall be assembled in a suitably labelled orange A4 size ring type binder of 

adequate size and with durable plastic covered hard covers, containing the following: 

Where the number of drawings exceeds 30 the drawings shall be bound in a separate A3 

ring binder. Each drawing shall be separately bound and enclosed in a plastic sleeve. 

(a) One copy of all "work as executed" drawings, schedules and arrangements. 

(b) One copy of any drawing supplied by The Department of Public Works and 

Services not incorporated under item (a). 

(c) A list of the names, addresses and phone numbers of all equipment suppliers. 

(d) Descriptive brochures and manufacturer's maintenance instructions and 

recommendations for all switchboard components and equipment. 

(e) A software description of the PLC programme where provided as part of the 

contract. 

(f) A complete listing of any PLC programme provided as part of the Contract. 

(g) A copy of Australian Standard AS 2467. 

Page 68 MEW E101

(g) SCADA system software description and functional description. 


(h) A schedule of "Fault Cause Action" for all faults of the plant. The "Cause" shall 

detail all possible causes. The action shall detail actions by both operator and 

electrician. 

(i) Any other information or instructions necessary for operation and maintenance of 

the switchboard. 

All pages and drawings shall be properly reinforced where attached to the binder. 

See also Clause 215 

Supply five copies of Operation and Maintenance Instruction Manuals. 

214 SWITCHBOARD ACCESSORIES 

Whenever fuses, racking handles, other spare parts and maintenance instruction books 

are to be stored, a non-lockable, labelled spare parts cabinet shall be supplied for 

installation adjacent to the switchboard. If space permits, this cabinet may be part of the 

switchboard. 

If the schedule holder is not mounted on the switchboard, it shall be supplied loose for 

installation in the switchroom. Refer to Clause 114.5. 

The drawout circuit breaker tripping battery with cabinet and charger shall be supplied 

loose for installation in the switchroom. 

215 HEAVY EQUIPMENT HANDLING 

Design objects to be handled for routine or maintenance purposes to, as far as 

reasonably practical, eliminate risks arising from manual handling. 

In particular, design switchboards, variable speed drive enclosures and other enclosures 

such that manual handling of equipment for routine or maintenance purposes is limited to 

a weight of no more than 16kg per person handling the equipment. 

If an object weighing more than 16kg for each person who could simultaneously, in a 

balanced and comfortable posture, access the object for handling purposes is required to 

be moved, nominate the mechanical aid to facilitate the handling of such an object. 

Advise the correct use of such a mechanical weight handling aid. Incorporate this data 

into the Operation and Maintenance Instruction Manual. 

Refer also to the National Standard for Manual Handling (NOHSC:1001) and the 

Occupational Health and Safety Regulation 2001. 

MEW E101 Page 69

Part 3 - Accessories 

PART 3 - ACCESSORIES 

301 ACCESSORIES GENERALLY 

Flush mounted light switches, isolating switches, socket outlets and other outlets shall be 

mounted in wall boxes. 

Outlets shall not be installed across the junction of different wall finishes. 

Installation methods are shown below: 

Wall Construction Installation Requirements 

Rendered brick partition Flush wall box - conduit chased into wall. 

Face brick partition Architrave switch with conduit channels cut in architrave. 

Flush wall box-conduit concealed in cut bricks. 

Face brick external Flush wall box - conduit run in cavity and tied against inner 

brick surface. 

Stud partition Flush wall box - conduit run in cavity. 

302 LAMPS AND LAMPHOLDERS 

302.1 Lamps 

Unless otherwise indicated: 

Stud mounting bracket - conduit run in cavity within 25 of 

the bracket. 

(a) All incandescent lamps shall be 250 volt grade, general service internally etched 

type with normal bayonet caps (B22) up to and including 100 watts, and screw 

caps (E40) above 100 watts. 

(b) Fluorescent lamps shall be straight fluorescent tubes of standard lengths, with bipin 

connection, hot cathodes and a phosphor colour temperature in the range 4100 

to 4300 degrees Kelvin. 

All 26 mm diameter lamps shall be switch start type. 

(c) Mercury vapour lamps shall be class MBF/U colour corrected mercury fluorescent 

lamps or class MBTF/U where self ballasted lamps are indicated and shall have 

E27 or E40 screw caps. 

(d) Sodium discharge lamps shall be high pressure sodium lamps with tubular or 

elliptical, frosted or clear glass envelope and shall have E27 or E40 screw caps. 

All screw caps shall have nickel plated contacts and ceramic insulating material between 

screw and button contact areas. 

302.2 Lampholders 

Bayonet-type lampholders and batten-holders shall comply with AS 3117 and generally 

be ceramic type although moulded type with brass lined shell may be used with lamps 

rated up to and including 60 watts. 

All screw type lampholders shall be ceramic or moulded glass filled polyester, long skirt 

type complying with AS 3140 and having the following features: 

(a) spring loaded and nickel plated contacts, 

(b) isolated nickel plated fixed screw shell, 

(c) nickel plated tunnel type terminals. 

Page 70 MEW E101

303 WALL MOUNTED SWITCHES 



Switches shall be of approved manufacture, of minimum 10 A rating, complying with AS 

3133 and the following: 

(a) Switches shall be of the flush type, fixed in wall boxes to suit the installation located 

as indicated. 

(b) Switchplates for switches other than ironclad shall be impact resistant plastic 

mouldings, suitably reinforced, of selected colour and finish. 

(c) Ironclad switches shall have the toggle fully recessed, or protected by shrouds. 

(d) Switches exposed to the weather, installed in trenches, in basement areas or in 

locations subject to dampness or condensation shall be approved to AS 1939- 

degree of protection IP56, and shall have a rotary action positive contact switch. 

(e) Switch mechanisms, fitted to a flush plate, shall be secured to the plate with 

retaining screws, or constructed so that switch mechanisms cannot be displaced. 

(f) Isolating switches shall be selected to meet the requirements of the location and 

function. A sample of the isolating switch to be used shall be submitted for 

approval prior to installation. 

(g) Where indicated, a pilot indicator comprising a neon lamp and ruby lens shall be 

incorporated within the switch or enclosure. 

303.2 Installation of Switches 

Switches installed adjacent to door openings shall be installed on the lock side of the 

door. Flush mounted wall switches shall be located vertically with a maximum of four 

switches to a single gang plate. 

Adjacent switches connected to different phases shall be shrouded. 

Mounting heights for switches shall be approximately 1200 to the centre of plate unless 

otherwise indicated. 

304 240 VOLT COMBINATION SWITCH SOCKETS 


Fittings and accessories shall be of approved manufacture and rating and shall be 

selected to meet the requirements of the location and function. Socket outlets shall have 

the earth pin located at the 6 o'clock position. Unless otherwise indicated, outlets shall 

have a 10 A rating. Where indicated, a pilot indicator, comprising a neon lamp and ruby 

lens, shall be incorporated in the enclosure. 

Unless otherwise indicated, flush plates for outlets other than ironclad, shall be impact 

resistant plastic mouldings, suitably reinforced, of selected colour and finish. 

Generally, power outlets shall be located in the fifth brick course above floor level or at 

300 above bench top height or as indicated. For walls of different construction a similar 

mounting height shall be used. 

For school projects, safety shutters shall be incorporated in 240 volt outlets. 

MEW E101 Page 71


304.2 Socket Outlets - Plastic Type 

Socket outlets shall comprise a combination switch and three-pin (flat pin) socket 

assembly. Where approved, the assembly may be installed on an impact resistant plastic 

moulded mounting block. 

304.3 Special Purpose Outlets 

SPO's shall comprise a combination switch and socket assembly, shall comply with AS 

3000 and shall be polarised as for socket outlets. 

305 240 VOLT COMBINATION SWITCH AND PERMANENTLY 

CONNECTED CORD OUTLET 

This outlet shall comprise an approved, three-terminal flush type switch and flex-lock 

insert assembly with an impact resistant plastic moulded flush plate, set flush in a single 

gang wall box. 

The flex-lock entry shall match the size and type of connected flexible cord and shall 

provide a secure grip for the cord. 

Where indicated, a pilot indicator, comprising a neon lamp and ruby lens, shall be 

incorporated within the switch enclosure. 

306 415 VOLT POWER OUTLET 

This outlet shall comprise an approved, heavy duty, five pin (round pin), surface mounted 

switch socket assembly, ironclad or of impact resistant plastic, with flap lid and complete 

with five pin plug top and screw ring for holding plug top in position. 

Outlets shall have the earth pin located at the 6 o'clock position, neutral pin in centre 

position and phase conductors connected such that a positive phase sequence will be 

indicated by a phase rotation meter connected by red, white and blue leads in a clockwise 

direction. 

Plugs shall be connected in a similar manner. 

The capacity of each outlet shall be suitable for the indicated load. Outlets shall be 

installed with a neutral conductor in all cases. 

307 EXTRA LOW VOLTAGE POWER OUTLET 

This outlet shall comprise a 2 pin socket outlet with flat pins at 90 degrees for DC, and 

flat parallel pins for AC, flush mounted, with flushplate to Clause 304.1, or surface 

mounted with ironclad or impact resistant plastic enclosures. 

308 CLOCK OUTLET 

This outlet shall comprise an approved 4 pin (round pin) receptacle complete with a plug 

top. 

When installed, the entire plug top and outlet shall be flush with the surface of the wall. 

Unless otherwise indicated, the mounting height shall be 2400 above finished floor level. 

309 LABELLING 

For labelling of items covered by Clauses 302 to 308 inclusive refer to Clause 603. 

Page 72 MEW E101

PART 4 - LUMINAIRES - SUPPLY AND INSTALLATION 

401 GENERAL 

Part 4 - Luminaires - Supply and Installation 

Luminaires shall be complete with incandescent lamps, fluorescent tubes, discharge 

lamps, and accessories necessary for their proper functioning and shall be in accordance 

with the provisions indicated herein. 

All fluorescent luminaires shall have low loss lead/lag ballasts and be switch start 26mm 

tubes. 

All discharge luminaires shall be power factor corrected to minimum of 0.85 lagging. 

Other blocking inductors shall be incorporated where indicated and/or where required by 

the Supply Authority. 

402 SUPPLY OF LUMINAIRES 

402.1 Luminaires Other than "Contract" Type 

These luminaires shall be purchased from a reputable supplier, and shall be 

manufactured in accordance with SAA Approval and Test Specification AS 3100, 

AS 3300 and AS 3137. 

The catalogue numbers or trade designations for luminaires used in the schedule of 

equipment are intended to indicate the required quality, style and performance of the 

luminaires. Where an alternative luminaire is offered, all performance data shall be 

submitted for approval. If requested, a sample shall be submitted for approval. 

403 INSTALLATION OF LUMINAIRES 


All screws, battens, roses, noggings, trims, packing, etc., necessary for the proper fixing 

of luminaires shall be provided by the Contractor as part of the works. Packing pieces of 

approved material shall be fitted where required to level the luminaires and to prevent 

distortion. 

Noggings shall be of similar size to the timber joists, and of minimum size 75 x 50. 

Unless otherwise indicated, in rooms with only one luminaire, the luminaires shall be 

centrally placed for even illumination. 

Where painted surfaces are damaged, they shall be made good by painting in 

accordance with Clause 601 to the same standard as the original paintwork. 

Fittings are to be installed subject to the agreement of the Main Contractor and the 

approval of the Superintendent. 

All luminaires shall be effectively earthed. 

All fixings in outdoor locations shall be stainless steel. 

Where rod suspensions are indicated, standard rod suspension sets as supplied by the 

fluorescent luminaires supplier shall be used, or, alternatively, rods shall be steel water 

pipe with gimbal mounting from ceiling. Rod length shall be adjusted so that the 

luminaires hang true. 

Where chain suspensions are indicated, standard chain suspension sets as supplied by 

the fluorescent luminaires contract supplier shall be used or alternatively, electroplated 

welded steel link chains/minimum 3 diameter steel shall be used. Chains shall be hook 

mounted from ceiling and lengths adjusted so that the luminaires hang true. 

403.2 Fluorescent Luminaires 

MEW E101 Page 73


Luminaires shall be supported by two fixing at each end. One fixing at each end of a 

narrow fitting will be accepted where a 1.6 mm thick back plate reinforces each fixing 

screw. 

End to end luminaires shall be correctly aligned using packing strips where necessary. 

Luminaires shall not be erected on sprayed acoustic ceilings until at least one week after 

the spraying of the ceilings has been completed. 

Luminaires shall not be supported or suspended from plastic boxes or fittings. Plastic 

boxes attached to luminaires for cable protection shall not be used as part of the fixing 

method. 

Where a PVC conduit enters a luminaire, a screwed PVC adaptor with circular lock nuts 

shall be used to secure the conduit to the luminaire. Lock nuts are not required for 

luminaires with screwed conduit entries. 

403.3 Surface Mounted Luminaires 

Luminaires shall be securely fixed to structural members of the ceilings or walls, or fixed 

by hangers or brackets which are securely fixed to structural members. 

403.3.1 Fixings for Surface Mounted Luminaires 

The minimum size of fixing for luminaires, hangers, or brackets for various surfaces shall 

be as follows: 

(a) Fixing to timber: steel wood screw No. 10 x 25, round head, cadmium plated. 

(b) Fixing to concrete: approved screw expanding bolts M5 x 40. 

(c) Fixing to hollow blocks: M5 electro galvanised, round head screws with spring 

loaded butterfly toggles. Where a deep cast iron junction box is provided in the 

centre, M5 metal screws shall be used with approved expanding fixing at each end. 

(d) Fixing to suspended ceilings shall be as indicated. 

All fixings shall be fitted with large diameter (minimum 3 x screw dia.) cadmium plated 

washers under the heads of each screw. 

403.3.2 Recessed Luminaires 

Recessed luminaires shall be fitted with flexible cords and 3 pin plugs. The flexible cord 

shall be PVC insulated, 3 core with 0.75 mm 2 conductors, and shall comply with AS 

3191. It shall be of suitable length not greater than 1500. 

A plug socket shall be located within 500 from the edge of the access aperture to allow 

the luminaire to be plugged-in prior to fixing. 

Recessed luminaires installed in timber-framed ceilings shall be fixed to the ceiling 

members and noggings using the proprietary fixings supplied by the luminaires 

manufacturer, subject to the approval of the Superintendent. 

Recessed luminaires using incandescent or discharge lamps and installed in a confined 

space (e.g. covered way, counter canopy, integrated ceiling/roof) shall be wired to a 

nearby junction box using cable having insulation at least rated to 200ºC maximum 

operating temperature. 

Recessed luminaires for suspended or modular ceilings shall be attached to suspended 

ceilings with proprietary mounting brackets supplied by the luminaire manufacturer. 

Page 74 MEW E101

403.4 Post Top Luminaires 

Post-top luminaire shall be mounted on tapered steel lighting columns. 


Unless otherwise indicated, lighting columns shall consist of proprietary brand steel poles, 

hot dipped galvanised and suitable for base plate mounting on galvanised rag bolt 

assembly set in a concrete pad. The poles shall be adequately drained and shall be fitted 

with an approved weatherproof lockable enclosure to house the control gear and fuse(s), 

in the lower section of the pole, within 1000 of the ground. 

403.5 Emergency Luminaires 

Emergency luminaires shall be non-maintained mode. 10W halogen fittings with 

separate battery pack. They shall be flush mounting on the ceiling with a charged LED 

and a discharge push-button. Battery shall provide a minimum two hours full illumination. 

403.6 Bollard Luminaires 

Bollards shall be flange plate mounted on a 500 x 500 x 500 reinforced concrete block. 

The bollard shall have integral controlgear. Body of the bollard shall be manufactured 

from minimum 2mm aluminium 150 diameter. Bollards shall be epoxy painted eucalyptus 

green or similar. Unless specified otherwise, bollards shall have 18W fluorescent tubes. 

MEW E101 Page 75

Part 5 - Electrical Motors 

PART 5 - ELECTRICAL MOTORS 

501 GENERAL 

All electric motors except special purpose motors shall have dimensions and outputs to 

AS 1360. 

Motors shall be three phase. However, single phase motors will be acceptable for 

smaller motors (e.g. 0.37 kW and below), where three phase motors are not 

manufactured. 

Motor design, marking, rating, performance and testing shall be in accordance with the 

requirements of AS 1359. 

Motors shall be designed to have a winding temperature rise to Class B (Class 130) 

requirements and be provided with Class H (Class 180) insulation to AS 2768. 

The motor and drive unit torque/speed characteristics shall ensure smooth positive 

acceleration in conjunction with the specified starting method. 

Motor ratings shall be continuously rated at an ambient temperature of at least 40ºC. 

Where a motor is installed in a location at which an ambient temperature greater than 

40ºC is indicated or, where due to design, a motor is installed in an ambient temperature 

greater than 40ºC, the motor shall either be rated for continuous operation at or above the 

ambient temperature or be oversized to the extent that its continuous operating 

temperature in the installed ambient shall not exceed its rated operating temperature. 

A motor oversized as above shall be derated by fixing to the frame a suitable label which 

will indicate the derated full load and the correct setting of the motor protective devices. 

The derated full load and the current drawn by the motor at the derated full load shall be 

used wherever reference is made to full load or full load current respectively in later 

clauses. 

Motors shall satisfy the Electricity Supply Authority's requirements particularly in regard to 

interference to other consumers and frequency injection systems. 

Motors shall be capable of starting direct on line and of operation within the voltage range 

of 370 to 440 volts, where three phase and 216 to 264 volts where single phase. 

Motors shall have a synchronous speed not exceeding 1500 r/min, except where higher 

speeds are specified. 

Nameplates shall be stamped or embossed, corrosion resistant, permanently fixed to the 

motor in a location adjacent to the terminal box and shall not be painted. 

Motors having pressed metal end shields are not acceptable. 

502 MOTOR BEARINGS 

Motors shall be fitted with ball or roller bearings. Bearings shall be either or the sealed 

type or have provision for greasing. For motors having a frame size greater than 132, 

provision shall be made for regular greasing of the bearings during their in-service life. 

(Sealed bearings are not acceptable). 

Where bearings require greasing, the greasing system shall permit the addition of grease 

whilst the motor is running, without the risk of over lubrication or injury to personnel and 

shall include a pressure relief grease valve to expel excess grease external to the motor. 

It shall allow old grease to be purged from the bearing during the regreasing operation. A 

name plate shall be attached to motors fitted with regreasable bearings stating the type of 

bearing installed and the lubrication instructions. 

For variable speed driven motors, which are sized at 90kW, 4 pole or greater (or an 

equivalent frame size for other than 4 pole motors), protect the non drive end bearings 

from shaft voltages using ceramic insulation material or equivalent. 

Page 76 MEW E101


For variable speed driven motors, which are sized at 90kW, 4 pole or greater (or an 

equivalent frame size for other than 4 pole motors) and which are located in hazardous 

locations, do not provide earthing brushes designed to remove the effect of electrical 

discharge through the bearings but provide drive and non drive end insulated bearings, 

using ceramic insulation material or equivalent. 

503 POWER FACTOR 

Single speed motors, when operating at rated full load and rated speed, shall exhibit 

power factors equal to or greater than those indicated in the following table: 

kW Rating Range 

Less than 0.5 kW 

0.5 kW 

to less than 1.1 kW 

1.1 kW 

to less than 5. 5 kW 

5.5 kW 

to less than 30 kW 

2 Pole 4 Pole 6 Pole 8 Pole 

p.f. p.f. p.f. p.f. 

0.62 0.62 0.62 0.56 

0.83 0.74 0.71 0.64 

0.84 0.77 0.72 0.65 

0.87 0.83 0.77 0.74 

30 kW to 100 kW 0.87 0.87 0.81 0.75 

Greater than 100 kW 0.89 0.87 0.81 0.77 

In selecting motors to drive the specified plant, the motors selected shall be sized to allow 

operation at the highest efficiencies possible, allowing for standard motor sizes and 

starting conditions, and shall operate at load factors between 75% and 95% of the motor 

full load ratings. 

504 MEPS COMPLIANCY 

Three phase squirrel cage induction motors, other than submersible motors, hazardous 

area motors and motors that are integral with and not separable from a driven unit or 

motors meeting clause 1.2 (Exclusions) of AS/NZS 1359.5:2004, shall be compliant to 

the Minimum Energy Performance Standard (MEPS) requirements of AS/NZS 

1359.5:2004, for all motors with ratings from 0.73kW to 185kW. 

Such motors shall meet either Table A3 (Heff-A) Minimum High Efficiency – Test Method 

A or Table B3 (Heff-B) Minimum High Efficiency – Test Method B of AS/NZS 

1359.5:2004. 

Provide a stainless steel label on the motor identifying MEPS compliancy as follows: 

“MEPS COMPLIANT TO AS/NZS 1359.5.2004, Table A3” 

or 

“MEPS COMPLIANT TO AS/NZS 1359.5.2004, Table B3” 

as applicable. 

Use minimum size lettering of 2.5 high for the above label. 

MEW E101 Page 77


505 POWER FACTOR CORRECTION 

When power factor correction capacitors are permitted and required they shall be 

supplied in three phase delta-connected units, fitted with fuses and internal discharge 

devices. All capacitors shall be housed in the SCA. 

When audio-frequency rejection is specified, the capacitors shall be fitted with frequency 

rejection devices tuned to the specified frequency. 

Power factor correction equipment is to comply with the requirements of the Electricity 

Distributor. 

In addition to the requirements of AS 1013 Clause 6.1 the capacitor unit rating plate shall 

be labelled "CAPACITOR UNIT DETAILS". 

506 MOTOR ENCLOSURES 

Enclosures for motors shall comply with the minimum requirements of the following table: 

Motors operating in Enclosure 

Areas designated hazardous Flameproof as specified 

Areas subject to hosing and external area IP 56 

Other Areas IP 54 

Motor cooling requirements shall be to IC 0141. 

Page 78 MEW E101

507 EMBEDDED OVERLOAD PROTECTION 


Embedded overload protection shall comprise thermistors embedded in the winding of 

each phase and connected to fixed terminals in the motor terminal section. The 

thermistors shall comply with AS 1023 Part 1 and shall be Class 1. Details of the type 

installed shall be attached to the motor nameplate. The thermistors shall be suitable for 

windings having a temperature rise meeting Class B requirements. 

All motors rated 15 kW and higher, and all motors used on water supply or sewerage 

projects rated 5.5 kW and higher, shall be fitted with thermistors unless otherwise 

indicated. A thermistor control unit in accordance with Clause 207.12.2 shall only be 

provided when indicated. 

508 ANTI-CONDENSATION HEATERS 

When indicated, two 240 volt 50 Hz anti-condensation heaters, connected in parallel, 

shall be fitted in the motor and connected to terminals in a separate terminal box. A 

nameplate on the motor shall state: 

(1) Heater Details 

(2) Number of Heaters 

(3) Voltage (240 V 50 Hz) 

(4) Power Rating. 

Anti-condensation heater terminal boxes shall be fitted with a sign stating: 

509 MOTOR TERMINAL BOX 

"WARNING: 240 VOLT ANTI-CONDENSATION HEATER 

CIRCUIT LIVE WHEN THE MOTOR IS OFF". 

Motor terminal boxes shall be of metallic construction, and be of adequate dimensions 

suitable for the entry and termination of the appropriately sized cables. 

All terminals shall be identified and coded in accordance with the requirements of AS 

1359.3 and an earth terminal shall be provided within the terminal box. 

Where thermistors and/or anti-condensation heaters are provided, terminals shall be 

suitably segregated and identified and a separate terminal box shall be provided for the 

anti-condensation heaters terminals. 

Each end of the motor phase windings shall be terminated on separate terminals within 

the motor terminal box for all single speed motors 5.5 kW and larger. 

In addition to the requirements of AS 1023.1 Clause 1.5 the thermistor nameplate shall 

be labelled. 

"THERMISTOR DETAILS" 

When specified, two 240 volt 50 Hz anti-condensation heaters, connected to terminals in 

a separate terminal box. A nameplate on the motor shall state: 

(1) "Heater Details" 

(2) Number of Heaters 

(3) Voltage (240 V 50 Hz) 

(4) Power Ratings 

Anti-condensation heater terminal boxes shall be fitted with a sign stating: 

"WARNING: ANTI-CONDENSATION HEATER 

CIRCUIT LIVE WHEN THE MOTOR IS OFF". 

MEW E101 Page 79


Motor terminal boxes shall be metallic construction and shall be of adequate dimensions 

and suitable for the entry and crimp-lug termination of the specified cable. 

All terminals shall be identified and coded. 

An earth terminal shall be provided inside the motor terminal box. 

510 PART WINDING START MOTORS 

These motors shall have two separate windings arranged so that for starting only one 

winding is energised. When the motor is up to speed the second winding is connected in 

parallel. The time delay between energising the two windings shall be set to that 

specified by the motor manufacturer and sealed by the installer of the equipment. 

511 HERMETICALLY AND ACCESSIBLE SEALED MOTORS 

These shall comprise proprietary units constructed by the recognised manufacturers to 

comply with current industrial practice. 

The protection shall comprise a suitable temperature sensing method arranged to 

interrupt the electricity supply in the event of the winding temperature exceeding the limit 

of the insulation temperature rating from whatever cause. This protection shall be in 

addition to over current protection in the control circuit and, for air conditioning plants, 

preferably shall be manually reset. 

512 SUBMERSIBLE MOTOR REQUIREMENTS 

The motor and driven unit torque/speed characteristics shall ensure smooth positive 

acceleration in conjunction with the scheduled starting method under all specified 

conditions of operation. The final speed during the first step of starting shall exceed the 

speed of breakdown torque. 

All motors will be started by means of automatic starters designed to AS 1202. 

Motors shall satisfy the Electricity Supply Authority's requirements particularly in regard to 

interference to other consumers and frequency injection systems. 

Motors shall be rated for type S1 duty in air, i.e. maximum continuously rated (MCR) in air 

using a method of cooling consistent with continuous operation with a water level at the 

top of the volute. The motor power required over the entire operating range, i.e. between 

maximum total head pipeline characteristic and 10% in excess of flow rate at flood head 

pipeline characteristic shall be less than the motor rating. 

Within the operating range the current in each phase shall be less than the MCR current 

for a supply voltage within the specified range, and for a voltage variation between 

phases which is within the tolerance that the Electricity Supply Authority permits. 

Motor starting, or continuous operation at MCR shall not cause a temperature rise in 

excess of that specified, and shall not cause nuisance operation of any protective device. 

Starting characteristics shall be Design B to AS1359.41. 

Motor winding insulation shall be Class 155, but the design of the motor shall ensure that 

the temperature of the windings does not exceed the limits for Class 130 insulation. 

All terminals shall be identified and coded to drawing E94A. 

Phase time sequence of the electricity supply will be red/white/blue (clockwise rotation) 

and the motor shall be suitable for connection of the motor cables directly to this supply 

sequence. Any interchanging of phases to achieve correct shaft rotation shall be within 

the motor terminal box. 

An earth terminal shall be provided inside the motor terminal box. 

The motor finish shall be in accordance with that indicated for the pump. 

Page 80 MEW E101


Each motor shall be supplied with cables suitable for use in sewage. Conductors shall be 

flexible with high conductivity tinned copper wire, ethylene propylene rubber (or equal) 

insulated and chlorosulphinated and polyethylene (CSP) or polychloroprene (PCP) 

sheathed. 

Power cores shall be continuously coloured, continuously numbered or fitted with wire 

numbers using one of the identification systems shown on Drawing E94A. 

Each cable shall be terminated at the motor using a cable gland, in such a way that there 

will be no undue mechanical stress on either the conductors or the motor terminals to 

which the cable is connected. 

Further, the termination system shall be such that water cannot reach the motor windings 

from a cut cable under a pressure of fifteen (15) metres head of water. 

Cables shall include control cores for each specified and other installed protection 

devices. Two control cores per device shall be provided. 

Each motor shall have no more than three cables and the cables shall be tied together 

with black nylon cable ties at 300 mm centres. Control cores shall be in one cable or may 

be part of the power cables. 

When determining cable sizes, the three motor cores of motors for Direct-on-Line starting 

only shall be taken as each carrying a current equal to MCR current. 

The rating of the motor power cores and earth cores shall be suitable for the motor 

supplied taking into account all debating factors of AS 3008.1, as the cables are run in 

conduit to the switchboard with the cables for each pump in a single conduit, and with the 

conduits for different pumps spaced by not less than 100 mm or more. 

Cables shall also be sized to ensure that with the pump operating at MCR, the total 

voltage drop in the motor cores shall not exceed 2.5% of the supply voltage. For stardelta 

or auto transformer starting cables shall be sized to ensure reliable starting in star. 

All motors above 4.5kW shall have six (6) power conductors for star-delta starting. 

Suitable precautions shall be taken to ensure that signal noise of sufficient quantity to 

produce nuisance tripping is not induced in the thermistor, seal failure or any other control 

cores. 

Control cores shall be permanently and indelibly marked at the free end as S1 and S2 for 

seal failure cores, T1 and T2 for thermistor cores and TB1 and TB2 for thermostat cores. 

The free end of each motor cable shall be fitted with a heat shrink seal giving a degree of 

protection of IPX8 to AS 1939 at 15 m head of water during delivery and prior to 

installation. 

Each cable or cable group to each motor shall be provided with a means of support. This 

support shall be by means of a stainless steel cable support hook provided by the 

Contractor and suitably sized stainless steel or nylon support stockings similar to those 

manufactured by MACEY CABLE PTY. LTD. of Newcastle, N.S.W. 

MEW E101 Page 81

Part 6 - Painting, Colour Coding and Labelling 

PART 6 - PAINTING, COLOUR CODING AND LABELLING 

601 PAINTING 


This section shall apply to "on site" painting of equipment. Unless otherwise indicated all 

surfaces of conduits, fittings, accessories, equipment and supports installed as part of the 

works shall be painted. Sheet metal enclosures shall be painted internally and externally. 

All equipment delivered to site already painted shall be thoroughly cleaned down and 

damaged or unsatisfactory painting made good. For painting of switchboards refer to 

Clause 209. 

Surface preparation and painting shall take place in a tradesman-like manner and 

coatings shall be applied free from runs, pinholes, misses, patchiness, non-uniform 

appearance or any other surface defects and all work shall be to the complete 

satisfaction of the Superintendent. 

All painter's plant, tool, gear, steps, trestles, scaffolding, dust covers, masking, etc., shall 

be provided by the Contractor as necessary for the completion of the work and for the 

protection of finished work. 

Painting shall not be carried out under adverse weather conditions or when work is wet 

with fog, mist or dew or when the work would be subject to damage by such conditions. 

Dust sheets, drop sheets and masking shall be used whenever necessary to protect 

finished work and any other surfaces or equipment from dirt or paint spotting. Paint spots 

and splashes shall be removed immediately from adjacent surfaces and any surface so 

damaged shall be restored. 

Under no circumstances shall paint be sprayed to surfaces unless prior approval has 

been given by the Superintendent in writing. Approval will be granted only in exceptional 

conditions he applies. 

The following surfaces shall not be painted: 

(a) Concealed conduits. 

(b) Chrome plated, stainless steel or anodised surfaces. 

(c) Bearing surfaces, slides, adjusting screws and any surface that is required to be 

unpainted for the correct operation or adjustment of the equipment. 

(d) Internal surfaces of galvanised cable troughs. 

(e) Galvanised steel poles, unless otherwise indicated. 

(f) Galvanised cable tray and ladder, unless otherwise indicated. 

(g) Motor and equipment nameplates. 

(h) Plastic or fibreglass surfaces, other than conduits, ducts and associated fittings. 

601.2 Paint Materials 

All paint products and surface preparation material shall comply with S.A.A. standards. 

AS 2204 Zinc rich organic primer 

AS 2603 2 pack epoxy 

Inhibitive metal primer. 

GPC-P-12/1 Solvent borne paint for galvanised steel. 

AS 2673 Alkyd micaceous iron oxide 

AS 2602 Full gloss exterior polyurethane 

AS 4025.1 Full gloss oil and petrol resistant enamel. 

AS 3730 Vinyl gloss exterior paint. 

Page 82 MEW E101


All paint and other preparations shall be best quality, non-poisonous, lead-free, prepared 

synthetic products of approved brand. They shall be brought to site in their original 

unopened containers, bearing the manufacturer's label, batch number, instructions for 

application and date of expiry where applicable. 

All materials in any one complete coating system shall be manufactured by the same 

manufacturer and shall be compatible with each other. 

All paint shall be stored under conditions which will not lead to deterioration of the paint 

and no paint shall be used after expiration of its shelf life and, in the case of a multi-pack 

paint, after expiration of its pot life. 

Surfaces which shall operate at temperatures in excess of 100ºC shall be primed, 

undercoated and finish coated with approved heat-resisting materials suitable for the 

temperature to be encountered. 

601.3 Preparation of Surfaces 

All surfaces shall be thoroughly dry, cleaned down, free from weld spatter, burrs, dust, 

rust, cement and grease. Metal surfaces shall be thoroughly wire brushed to remove 

loose rust and scale. All sharp edges shall be rounded off to a radius of curvature of not 

less than 1. Butt welds shall be ground to a reasonably smooth surface free of sharp 

crests. Deposits of oil or grease shall be removed by solvent cleaning generally in 

accordance with AS 1627.1. 

Galvanised or zinc coated steel surfaces shall be cleaned by washing with potable water 

using nylon pads or brushes. After cleaning, the surface shall be thoroughly degreased 

by washing with mineral turpentine; alternatively a dispersion cleaner may be used if so 

recommended by the paint manufacturer. Soaps and detergents shall not be used for 

degreasing. The prime coat of the coating system shall be applied within 4 hours of 

completion of surface preparation. 

601.4 Application of Coating Materials 

601.4.1 General 

The paint manufacturer's printed recommendations shall be strictly observed, with 

particular reference to requirements for mixing, thinning, application techniques, drying 

time between coats and dry film thickness of each coat. 

No painting shall be carried out at ambient temperatures below 10ºC or above 30ºC or if 

the surface to be painted is less than 3ºC above the dew point or if the relative humidity is 

greater than 85%. 

Where two coats of otherwise identical paint are to be applied consecutively, each coat 

shall be of a different shade in the selected colour. The final coat shall be left smooth, 

even and free from visible brush marks and other defects. 

Painting of steel surfaces shall be to AS 2312 MP4-A. 

601.4.2 Prime Coating 

Steel surfaces shall be prime coated with a zinc rich organic primer. The prime coat shall 

be applied to a minimum dry film thickness of 70 micrometres. 

Galvanised or zinc coated steel surfaces shall be prime coated with a zinc dust 

pigmented drying oil primer for galvanised surfaces, followed by a micaceous iron oxide 

long oil alkyd or phenolic modified alkyd paint. Each prime coat shall be applied to a 

minimum dry film thickness of 40 micrometres. 

Non-ferrous metal surfaces shall be lightly abraded by light whip blasting or sanding then 

prime coated with a non-reactive two-pack epoxy primer to a dry film thickness of not less 

than 20 micrometres not more than 35 micrometres. 

Plastic surfaces shall be etch prime coated with an automotive lacquer thinner. 

MEW E101 Page 83


601.4.3 Finish Coating 

Steel surfaces shall be finish coated with two coats of a pigmented gloss alkyd enamel 

paint conforming to S.A.A. The total dry film thickness of the completed coating system 

shall be not less than 140 micrometres. 

Galvanised or zinc coated steel surfaces shall be finish coated with two coats of a 

pigmented gloss alkyd enamel paint. The total dry film thickness of the completed 

coating system shall be not less than 150 micrometres. 

Non-ferrous metal surfaces shall be finish-coated as for galvanised surfaces. 

Plastic surfaces shall be finish coated with two coats of a pigmented water borne gloss 

acrylic paint. The total dry film thickness of the completed coating system shall be not 

less than 70 micrometres. 

602 COLOUR CODING 

All exposed conduits, cable enclosures and cable troughing installed in switchrooms, 

boiler rooms, plant rooms, tank rooms, accessible trenches and masonry ducts shall be 

coloured light orange, colour X15 AS 2700. 

Elsewhere all such exposed material shall be coloured to match its surroundings, unless 

otherwise indicated. 

Cable enclosures, etc., within switchboard cupboards shall be considered concealed and 

need not be colour-coded or painted except that enclosures which form an extension of 

the switchboard shall be painted to match the switchboard. 

603 LABELLING 

Switches, socket outlets, SPO's, permanently connected outlets and power outlets, etc., 

shall be labelled in an approved manner to provide ready identification. 

Hand painted, embossed plastic or metal tapes and adhesive fixed labels are not 

acceptable. 

A stamped metal tag shall be securely tied to the termination of the consumer's mains 

cable, giving details of the size, number and material of the conductors. 

A similar metal tag shall be attached to each end of all spare pipes and conduits, stating 

purpose and point of termination. 

An approved traffolyte label with 10mm high black lettering reading: "WARNING - DO 

NOT USE THIS ROOM FOR STORAGE" shall be supplied for each switchroom and 

switchboard cupboard. The label shall be installed in a prominent location on the door or 

switchrooms/switchboard cupboards, as directed. 

For labelling of switchboards refer to Clause 210. 

For labelling of MEPS compliant motors, refer to Clause 504. 

Page 84 MEW E101

Index 

TABLE OF CONTENTS 

PAGE 

PART Ø - GENERAL 1 

0.1 SCOPE 1 

0.2 USER GUIDELINE FOR THE SELECTION OF SWITCHBOARD 

CLASSIFICATION 1 

0.3 STANDARDS 2 

0.4 ABBREVIATIONS 4 

PART 1 - INSTALLATION 5 

101 SETTING OUT OF RUNS 5 

102 PENETRATIONS 5 

102.1 Generally 5 

102.2 Penetrations Through Waterproof Membranes 5 

102.3 Penetrations Through External or Existing Structures 5 

102.4 Unenclosed Cables Passing Through Slabs 6 

103 AERIAL RETICULATION (POWER) 6 

103.1 Attachment to Poles 6 

103.2 Attachment to Buildings 6 

103.3 Poles 6 

103.3.1 Generally 6 

103.3.2 Hardwood Poles 6 

103.3.3 Crossarms 6 

103.3.4 Service Poles 7 

103.4 Aerial Cables 7 

104. UNDERGROUND RETICULATION 7 

104.1 Trenching, Backfilling and Reinstatement 7 

Page 85 MEW E101

MEW E101 Page 86 

INDEX 


104.1.2 Inspection 7 

104.1.3 Backfilling and Reinstatement 8 

104.2 Underground Cable Protection 8 

104.3 Underground Cable Draw-In Pits 8 

105 MARKING PLATES FOR UNDERGROUND RETICULATION 9 


105.2 Indication of Cable Entry to Buildings 9 

105.3 Indication of Directional Changes 9 

105.4 Indication of Cables Under Roads and Paths 10 

105.5 Indication of Terminated Conduits 10 

106 CABLES AND WIRING 10 


106.2 Consumer's Mains and Metering 10 

106.3 Final Sub-Circuit Wiring 11 


106.4 Instrumentation Cables 11 

106.5 Insulated Non-Armoured Cables in Enclosures (TPI) 12 

106.6 Underground Grade Insulated and Sheathed Non-Armoured Cables (TPS) 12 

106.7 Armoured and Sheathed Cables (Other than Paper Insulated) 12 

106.8 Aerial Cables 12 

106.9 Special Purpose 12 

106.9.1 Essential Service Cables 12 

106.9.2 Telephone Cables 12 

106.9.3 Fire Alarm Cables 13 

106.9.4 Security Cables 13 

106.10 Control Cabling 13 

107 EARTHING 13 

107.1 Generally 13

Index 

107.2 Earthing Conductors for Underground Cables 14 

107.3 Earth Electrodes 14 

108 CONDUITS, FITTINGS AND JOINTS 14 


108.2 Heavy Duty UPVC Conduits to AS 2053 (HD-UPVC) 14 

108.3 Steel Conduits 15 

108.4 Light Duty UPVC Conduits to AS 2053 (LD-UPVC) 15 

108.5 Flexible Conduits 15 

108.6 Installation 15 


108.6.2 Conduit Saddles 16 

108.6.3 Expansion Joints 16 

108.7 Conduits in Roof Spaces 16 

108.8 Conduits in Concrete 18 


108.8.2 Conduits in Suspended Slabs 18 

108.8.3 Conduits in General Columns 18 

108.9 Draw-In Points 18 

108.10 Conduits and Pipes for Future Use 18 

108.11 Wall Boxes 19 

109 CONDUIT SYSTEMS FOR COMMUNICATION SERVICES 19 

109.1 Conduits for Telecommunication Facility Cabling 19 

109.2 Conduits for Telecommunication Lead-In and Block Cabling 19 

110 CABLE TRAY, LADDER AND TROUGHING 20 


110.2 Cable Tray 20 

110.3 Cable Ladder 20 

110.4 Installation 20 

110.5 Cable Troughing 21 


Page 87 MEW E101


INDEX 

110.5.2 Metal Cable Troughing 21 

110.5.3 Plastic Cable Troughing 21 

110.5.4 Skirting Troughing 21 

111 FIXINGS 21 


111.2 Conduits 22 

111.3 Mounting Blocks 22 

111.4 Switchboards 22 

111.5 Switch Panels, Boxes 22 

111.6 Surface Mounted Switches 22 

111.7 Cable Troughing, Cable Tray, Skirting Troughing 22 

111.8 Metal Channel 23 

111.9 Hollow Block Locations 23 

111.10 Fixing of Luminaires 23 

111.11 Fixing of Ceiling Fans 23 

112 INSTALLATION OF SWITCHBOARDS 23 


112.2 Fixings 23 

112.3 Cables, Cable Enclosure and Busway Entry and Termination 23 

112.4 Schedules and Drawings 25 

113 WORK AS EXECUTED DRAWINGS 25 

113.1 Drawings Produced by Modification of Exhibited Drawings 25 

113.2 New Drawings Submitted by the Contractor 25 

114 ACCREDITATION FOR ‘CONTESTABLE WORKS” 25 

114.1 Level 1 Accreditation 25 



PART 2 - SWITCHBOARDS AND ASSOCIATED EQUIPMENT 27

Index 

201 SCOPE 27 

202 GENERALLY 27 

202.1 Classification of Switchboards 27 

202.1.1 Proprietary Assemblies 27 

202.1.2 Custom-built Assembly Type “CT” 28 

202.1.3 Custom-built Assembly Type “CU” 28 

202.1.4 Custom-built Assembly Type “DT” 29 

202.1.5 Custom-built Assembly Type “DU” 30 

202.1.6 Custom-built Assembly Type “DUPLUS” 31 

202.1.7 Custom-built Assembly Type “DTPLUS” 32 

202.1.8 Manufacturer of the Switchboard. 33 

203 FAULT LEVELS AND LIMITATION 33 

203.1 Fault Levels and Time of Duration 33 

203.2 Fault Current Limiting 34 

203.3 Short Circuit Co-ordination 34 

204 BUSBARS 34 


204.2 Material 34 

204.3 Sizes 34 

204.4 Jointing 36 

204.5 Supports 36 

204.6 Prevention of Arcing Faults 37 

204.6.1 Rigid Insulation 37 

204.6.2 Coating of Busbars and Terminations 37 

204.6.3 Application of Busbar Coatings 37 

204.7 Phase Identification 38 

204.8 Busbar Clearances 38 

204.9 Cable Connection Flags 38 

204.10 Neutral and Earth Busbars 38 

204.11 Flexible Busbars Take Offs 38 

Page 89 MEW E101


INDEX 

205 CABLING 38 


205.2 Cable Identification 39 

205.3 Large Cables (Cables above 6mm²) 40 

205.4 Small Cables (Cables up to and including 6mm ²) 41 

206 ACTIVE, EARTH AND NEUTRAL LINKS 41 

206.1 For Proprietary Assemblies 41 

206.2 For Custom-built Assemblies 41 

207 EQUIPMENT 42 

207.1 Compliance with Australian Standards 42 

207.2 Ambient Temperature 42 

207.3 Miniature Overcurrent and Moulded Case Circuit Breakers 42 

207.4 Drawout Circuit Breakers and Tripping Battery 43 

207.4.1 Drawout Circuit Breaker 43 

207.5 Fuses 43 

207.6 Fuse Combination Units 44 

207.7 Main Switches 44 

207.8 Contactors 45 

207.9 Control Switching Devices 45 

207.9.1 Instantaneous Relays 45 

207.9.2 Time Delay Relays 46 

207.9.3 Control Switches 46 

207.9.4 Push Button Switches 46 

207.10 Phase Failure Relays 47 

207.11 Residual Current Devices (RCD) 47 

207.12 A. C. Motor Starters 47 

207.12.1 General 47 

207.12.2 Direct-On-Line Starters 47 

207.12.3 Reduced Voltage Starters 48 

207.12.4 Reversing Starters 48

Index 

207.12.5 Electronic Soft Starter 49 

207.13 Motor Protection Devices 49 

207.13.1 Three Phase Motor Protection 49 

207.13.2 Motor Protection 49 

207.13.3 Single Phase Motor Protection 50 

207.14 Time Switches 51 

207.15 Hour Run Meters 51 

207.16 Indicating Counters 51 

207.17 Extra-Low Voltage Transformers 51 

207.18 Current Transformers (CTS) (Not Applicable to Supply Authority Equipment or 

Protection CTS) 51 

207.19 Meters and Associated Controls (Not applicable to Supply Authority Equipment) 52 

207.19.1 Voltmeters, Ammeters, Maximum Demand Indicators and Associated Controls 52 

207.19.2 Energy Meters 52 

207.20 Indicating Lights 53 

207.21 Variable Speed Drives 53 

207.22 Audible Alarm Devices 56 

207.23 Terminals 56 

207.24 Locking 56 

207.25 Ambient Temperature 56 

208 SWITCHBOARD CONSTRUCTION 58 


208.2 Externally Mounted Switchboards 58 

208.3 General Cubicle Construction 59 

208.4 Construction of Covers and Doors 59 

208.5 Spacing and Mounting of Circuit Breakers 60 


208.5.2 Circuit Breakers Not Larger than 160 Amps 60 

208.5.3 Circuit Breakers Larger than 160 Amps 60 

208.5.4 Circuit Breakers of the Drawout Type 60 

208.6 Spacing and Mounting of Fuse Combination Units 60 

Page 91 MEW E101


INDEX 

208.7 Space for Future Circuit Breakers and Fuse Combination Units 61 

208.8 Mounting Heights 61 

208.9 Extra Low Voltage 61 

208.10 Auto-transformer Compartment 61 

208.11 Arrangement of Equipment 61 

209 PAINTING OF SWITCHBOARDS 62 


209.2 Paint Materials 62 

209.3 Surface Preparation 62 

209.4 Painting and Finish 62 

210 LABELLING OF SWITCHBOARDS 62 


210.2 Fixing of Labels 63 

210.3 Labels on Exterior of Switchboards and Schedules 63 

210.4 Labels on Interior of Switchboards 64 

210.5 Warning Labels 64 

210.6 Special Label on Custom-built Assemblies 65 

211 INSPECTION AND TESTING 66 


211.2 Inspection 66 

211.3 Residual Current Equipment Testing 66 

211.4 Dielectric Tests 66 

211.5 Functional Testing 66 

211.6 Checking of Safety Measures and Electrical Continuity of Earthing Circuit 66 

212 DRAWINGS 67 


212.2 Switchboard Drawings and Equipment Schedules 67 

212.3 Additional Information on Custom-built Assembly Drawings 67 

212.4 Drawings Produced by Modification of Exhibited Drawings 68

Index 

212.5 New Drawings Submitted by the Contractor 68 

213 OPERATION AND MAINTENANCE INSTRUCTIONS MANUALS 68 

214 SWITCHBOARD ACCESSORIES 69 

215 HEAVY EQUIPMENT HANDLING 69 

PART 3 - ACCESSORIES 70 

301 ACCESSORIES GENERALLY 70 

302 LAMPS AND LAMPHOLDERS 70 

302.1 Lamps 70 

302.2 Lampholders 70 

303 WALL MOUNTED SWITCHES 71 


303.2 Installation of Switches 71 

304 240 VOLT COMBINATION SWITCH SOCKETS 71 


304.2 Socket Outlets - Plastic Type 72 

304.3 Special Purpose Outlets 72 

305 240 VOLT COMBINATION SWITCH AND PERMANENTLY CONNECTED 

CORD OUTLET 72 

306 415 VOLT POWER OUTLET 72 

307 EXTRA LOW VOLTAGE POWER OUTLET 72 

308 CLOCK OUTLET 72 

309 LABELLING 72 

PART 4 - LUMINAIRES - SUPPLY AND INSTALLATION 73 

401 GENERAL 73 

402 SUPPLY OF LUMINAIRES 73 

Page 93 MEW E101


INDEX 

402.1 Luminaires Other than "Contract" Type 73 

403 INSTALLATION OF LUMINAIRES 73 


403.2 Fluorescent Luminaires 73 

403.3 Surface Mounted Luminaires 74 

403.3.1 Fixings for Surface Mounted Luminaires 74 

403.3.2 Recessed Luminaires 74 

403.4 Post Top Luminaires 75 

403.5 Emergency Luminaires 75 

403.6 Bollard Luminaires 75 

PART 5 - ELECTRICAL MOTORS 76 

501 GENERAL 76 

502 MOTOR BEARINGS 76 

503 POWER FACTOR 77 

504 MEPS COMPLIANCY 77 

505 POWER FACTOR CORRECTION 78 

506 MOTOR ENCLOSURES 78 

507 EMBEDDED OVERLOAD PROTECTION 79 

508 ANTI-CONDENSATION HEATERS 79 

509 MOTOR TERMINAL BOX 79 

510 PART WINDING START MOTORS 80 

511 HERMETICALLY AND ACCESSIBLE SEALED MOTORS 80 

512 SUBMERSIBLE MOTOR REQUIREMENTS 80 

PART 6 - PAINTING, COLOUR CODING AND LABELLING 82 

601 PAINTING 82

Index 


601.2 Paint Materials 82 

601.3 Preparation of Surfaces 83 

601.4 Application of Coating Materials 83 

601.4.1 General 83 

601.4.2 Prime Coating 83 

601.4.3 Finish Coating 84 

602 COLOUR CODING 84 

603 LABELLING 84 

Page 95 MEW E101

electrical services minimum requirement - NSW Public Works

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