electrical services minimum requirement - NSW Public Works

Part 1 - Installation
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