The new IEC 61439 standard

The new IEC 61439 standard applies to enclosures

for which the rated voltage is under 1000 V AC

(at frequencies not exceeding 1000 Hz) or 1500 V DC.

The standard defines the design verified ASSEMBLIES

and eliminates completely the categories TTA and PTTA.

In order to conform to the standard, type tests have been

replaced by a design verification which can be carried

out by the three following equivalent and alternative

methods: testing, calculation/measurement or

application of design rules.

 

The following parts are mentioned and do not have equal

weighting. There is a formal hierarchy. Each part cannot be

used individually:

 

−− IEC 61439-1 "General rules"

−− IEC 61439-2 "Power switchgear and control gear ASSEMBLIES"

−− IEC 61439-3 "Distribution boards"

−− IEC 61439-4 "ASSEMBLIES for construction sites"

−− IEC 61439-5 "ASSEMBLIES for power distribution"

−− IEC 61439-6 "Busbar trunking systems"

 

Part 1 is the general rules part and cannot be used alone to

specify an ASSEMBLY.

 

Part 2 defines the specific requirements of power switchgear

and controlgear ASSEMBLIES (PSC ASSEMBLIES) and must

be used with Part 1. This is the only part that has a double

role, it covers PSC ASS EMBLIES and any ASS EMBLY which

is not covered by any other specific parts.

 

Parts 3-X are still under preparation but are already mentioned

in Part 1. These could be more than four, as additional

parts may be developed as the need arises.

 

Summarising:

With the currently used IEC 60439, the rule

is "one part for each type of ASS EMBLY". With the new

IEC 61439 the rule is "two parts for each type of ASSEMBLY".

The compliance of an ASSEMBLY is declared referring

to the specific ASS EMBLY standard (e.g. IEC 61439-2),

and the compliance with the general rules (IEC 61439-1) is

always implicit. The sentence "TTA switchgear according to

IEC 60439-1" is now replaced by "Power switchgear and

 

controlgear

ASSEMBLIES according to IEC 61439-2, design

verified ASS EMBLY".

The validity of the two standards will overlap until 2014 and

prior to this date, ASSEMBLIES can be manufactured according

to IEC 61439 or IEC 60439.

 

Copyright by :

ABB The new standard for low-voltage

switchgear and controlgear assEmblies