Changes within IEC 61439-1 & 2 Ed 3

[abbymiddleton]

After nine years of committee debate the 3rd Editions of IEC 61439-1 and IEC 61439-2, the standards for power switchgear and control gear assemblies, have been published. The new editions include changes, the significance of which will affect the way assemblies are specified and used.

These are the standards that most industrial/commercial switchboards and motor control centers are required to conform too. The new editions include may changes, some significant and one fundamental change.

The purpose of this webinar is to briefly mention some of the more significant changes and then to focus on the one fundamental change – the opportunities it brings and the care that is needed to ensure it is used correctly.

Any question, comment this post below to get our experts inputs 

[abbymiddleton]

Question from LIVE Webinar: 

Q: ­Consultant normally apply diversity factor on final, sub-mains and overall circuits. is manufacturer applying diversity over diversity on the panels?­

A: If Consultant’s are applying diversity and assuming they are specifying the nominal rating of the device, effectively they are taking responsibility for the rating of the circuit within the assembly. Depending on which rating the manufacturer assumes has been specified there may be duplication of diversity. The objective of the new standard is to avoid this confusion by asking the consultant to specify the design current of the circuit within the installation, and make the assembly manufacturer responsible for providing an assembly suitable for the application.

[abbymiddleton]

Question from LIVE Webinar: 

Q: ­Can you summaries some of the additional content regarding PV assemblies (or will you be giving another presentation­ on that?­

A. Depending on interest, Schneider may provide another webinar on PV assemblies, but in the mean time the additional requirements include:

1. Unless agreed otherwise between user and manufacturer, all assemblies are to be such that all circuits can be loaded to their rated current simultaneously and continuously (no diversity).
2. Solar irradiance must be taken into account when assemblies are subject to direct sun.
3. Assemblies must have an IK (impact) rating.
4. PV assemblies forming part of a DC installation must be Class II.
5. Assemblies are required to have a verified thermal cycling durability and a climatic durability

[abbymiddleton]

Question from LIVE Webinar: 

Q: ­Is the IEC 61439 applicable to the feeder pillar which are assembled with busbar and single isolated protection devices?­

A: IEC 61439 is applicable to feeder pillars, but if there is just one protection device in the pillar it may fall within the scope of IEC 60947-2.  Individual self-contained (enclosed) devices are precluded in the scope of IEC 61439-1.

[abbymiddleton]

Question from LIVE Webinar: 

Q: ­Not particularly related to 51439, but given IAC is de rigeur to MV switchgear, why is 61641 only a TR?   Also, what would you say to someone who suggested 61439 compliance gives class A compliance to 61641?­

A: The effects of a low-voltage arc is a little unpredictable and hence testing once does not guarantee an arc in a seemingly identical situation will behave in the same way. For this reason the document has to date been a TR, a statement of good practice.  However, there is a view that the next revision should move the document on to a Technical Specification or even a Standard.

Compliance with IEC 61439-1 does not demonstrate the requirements Class A of IEC 61641 are fulfilled. Additional arc fault tests with satisfactory result are necessary to comply with IEC 61641.