Assembly standards - Schneider Electric

Assembly standards - Schneider Electric

Low Voltage Systems Newsletter

The Low Voltage Switchgear & Controlgear

Assembly standards

The move from IEC 60439-X to 61439-X

Schneider Electric East Mediterranean

Low Voltage Systems Newsletter Issue #1 - April 2011

> 1

Low Voltage Systems Newsletter


The International ASSEMBLY Standards ................................... 2

From IEC 60439-1 to IEC 61439-1&2

Why a New Standard?....................................................................... 3

Clear Definitions of Roles ............................................................... 3

Elimination of TTA and PTTA Concepts .................................... 3

Clarified & Reinforced Requirements ......................................... 5

Strength of materials and parts

Overview of the Design Verifications ......................................... 5

(according to IEC 61439-2, in order of appearance)

Overview of the Routine Verifications ....................................... 6

> 1

Low Voltage Systems Newsletter

The International ASSEMBLY Standards

From IEC 60439-1 to IEC 61439-1&2

OLD IEC 60439-X

LV switchgear

& controlgear



Power switchgear and controlgear assemblies

TTA and PTTA (Also used as a general rules standard) 60439-1

Busbar Trunkings




Boards for

unskilled pers.



for construction




for public



NEW IEC 61439-X

LV switchgear

& controlgear



Power switchgear

and controlgear


61439-2 (2009)


Boards for

Ordinary pers.


General rules

61439-1 (2009)


for construction




for public







• IEC 61439-2 is to be read in conjunction with IEC 61439-1, instead of IEC 60439-1 alone

• Structure aligned with Standard for protection devices IEC60947

• Tests identical to those in IEC 60439-1 do not need to be repeat

> 2

Low Voltage Systems Newsletter

Why a New Standard?

• 80% of the ASSEMBLIES worldwide do not comply with the standard

• Requirements not always clear

• Role of Switchboard System manufacturer and Panel Builder not clear enough

• A Partially Type Tested ASSEMBLY (PTTA) concept abused and misused

Main Changes

• Recognition of Original Manufacturer (Switchboard System manufacturer)

and ASSEMBLY Manufacturer (Panel Builder)

• PTTA/TTA concepts replaced with (tested) ASSEMBLY

• Clarified & reinforced requirements

Clear Definitions of Roles

• ASSEMBLY Manufacturer (Panel Builder)

• Takes the responsibility for the final Assembly

• Carries out routine verifications

• Original Manufacturer (System manufacturer)

• Carries out the original design

• Carries out the design verifications

that can be certified through a certification body



• Full range of mechanical & electrical components

(functional units, switching devices, enclosures…)

designed by the Original Manufacturer to be

assembled according to his instructions

• Specifier (design office, End user,…)

• Specifies or selects the ASSEMBLY





IEC61439-1 & 2 Standard



Elimination of TTA and PTTA concepts


Project Specification



(Panel Builder)

Tested assembly


Type Tested Assemblies

Partially Type Tested Assemblies


• 7 type tests on the design

• 3 routine tests on the realization of each panel


• Calculations not clearly defined to justify not to do some type-tests

• 3 same routine tests


Design verifications

• Mainly type-tests

• Or possibility for only some of the verifications under clear and strict

conditions to do

• Comparison with a tested reference design (Design Rules)

• Calculations including safety margins

Routine verifications

• Same as TTA in 10 items instead of 3

> 3

Low Voltage Systems Newsletter

IEC61439-1 & 2 Standard


Characteristic to be verified

Clauses or



by testing

Verification options available


by calculation

1 Strength of Material and Parts: 10.2

Resistance to corrosion 10.2.2 Yes No No

Properties of Insulating Materials: 10.2.3

Thermal stability Yes No No

Resistance of insulating

Materials to normal heat Yes No No

Resistance to abnormal heat and fire due to

internal electric effects Yes No No

Resistance to ultra-violet (UV) radiation 10.2.4 Yes No No

Lifting 10.2.5 Yes No No

Mechanical impact 10.2.6 Yes No No

Marking 10.2.7 Yes No No

2 Degree of Protection of Enclosures 10.3 Yes No Yes

3 Clearance and Creepage Distances 10.4 Yes Yes Yes

4 Protection against electric shock

and integrity of protective circuits:


Effective continuity between the exposed

conductive parts of the ASSEMBLY and the 10.5.2 Yes No No

protective circuit

Effectiveness of the assembly for external faults 10.5.3 Yes Yes Yes

5 Incorporation of switching devices

and Components

10.6 No No Yes

6 Internal electrical circuits and connections 10.7 No No Yes

7 Terminal for external conductors 10.8 No No Yes

8 Dielectric properties: 10.9

Power-frequency withstand voltage 10.9.2 Yes No No

Impulse withstand voltage 10.9.3 Yes Yes

9 Temperature-rise limits 10.10 Yes Yes Yes

10 Short-circuit withstand strength 10.11 Yes Yes Yes

11 Electromagnetic compatibility (EMC) 10.12 Yes No Yes

12 Mechanical operation 10.13 Yes No No


by design


> 4

Low Voltage Systems Newsletter

Clarified & Reinforced Requirements:

Strength of materials and parts

• Following tests are compulsory

This looks at the suitability of plastic and metal parts to prove the long term capabilities

of the equipment.

• Resistance to corrosion

• Properties of insulating materials

• Thermal stability

• Resistance of insulating materials to normal heat

• Resistance to abnormal heat and fire due to internal electric effects

• Resistance to ultra-violet (UV) radiation

• Lifting

• Mechanical impact (IK)

• Marking

• Current carrying

• All the tests (also short circuit) have to be made with the devices inside the assembly

• No more possibility to make a temperature rise with a heating resistance

• No device substitution

• The tests have to be made

• for each circuit alone to its rated current

• and the complete assembly (including diversity factor)

• The verification by calculation is limited

• maximum 1600A and all components de-rated to 80%

> 5

Low Voltage Systems Newsletter

Overview of The Design Verifications

(according to IEC 61439-2, in order of appearance)


• Resistance to corrosion

• Thermal stability of insulating materials (dry heat test)

(a new ball pressure test will be withdrawn from Edition 2)

• Resistance to abnormal heat due to internal electric effects (glow-wire test) (8)

• UV radiation test (outdoor ASSEMBLIES only)

• Lifting test

• IK test, where specified

• Marking

• Degree of protection of enclosures (7)

• Clearances (higher minimums) and creepage distances (5)

• Continuity between exposed conductive parts and the protective circuit (4.1)

• Effectiveness of the protective circuit for external faults (4.2)

• Incorporation of switching devices and components

• Internal circuits and connections

• Terminals for external conductors


• Power-frequency voltage test (2) (complying with IEC60947)

• Impulse withstand voltage test (no more optional)

• Temperature rise limits (1)

• Short-circuit withstand strength (3)

• Electro-Magnetic Compatibility (9)

• Mechanical operation (6) (200 operating cycles instead of 50)


• (1) to (7) show the 7 type-tests according to table 7 of IEC 60439-1 (items 1 to 7)

• (8) and (9) were also required but not in table 7

> 6

Low Voltage Systems Newsletter

Overview of The Routine Verifications

Routine Verification Visual inspection Tests

Degree of protection of enclosures


Clearances X or measurement if specified values (in 1 st Ed (2009)

of IEC 61439 -1 these values are 1,5 times the values

in Ed 2 to be published in 2011 (and in IEC 60439- 1)

or impulse withstand voltage test

Creepage distances X or measurement if visual inspection not applicable

Protection against electric shock and integrity

of protective circuits

Incorporation of built-in components



Random verification of tightness of the connections of

protective circuit

Internal electrical circuits and connections X Or Random verification of tightness

Terminals for external conductors

Number, type and identification of terminals

Mechanical operation X effectiveness of mechanical actuating elements

locks and interlocks, including those associated with

removable parts

Power-frequency dielectric test or verification of

Dielectric properties

insulating resistance (with incoming up to 250A only)


Verification of completeness of information & markings,

Wiring, operational performance and function

inspection of wiring and Function test where relevant

> 7

Low Voltage Systems Newsletter

Become A Champion

of Energy Efficiency.

Enroll at today!

Energy University

courses are:

> On demand

> Less than an hour

> Free of charge

> 8

Low Voltage Systems Newsletter

To find out more:

Schneider Electric East Mediterranean s.a.l.

Ashadia Building, 10 th Floor, Tabaris, Achrafieh

P.O. Box : 166223 - Beirut, Lebanon

Tel. +961 1 204 502

Fax +961 1 204 458

Cyprus + 357 24 812 649 •

Iraq + 962 6 516 6260 •

Jordan + 962 6 516 6465 •

Lebanon + 961 1 321 645 •

Syria + 963 11 6124799 •

> 9

More magazines by this user
Similar magazines