Apply HV 60Hz CB at 50 Hz

[Modula2]

Ansi equipment on 50 Hz project. 4.16 KV vacuum CB's designed to previous C37 constant MVA rating, not the newer standards in the C37 series which have constant KA ratings.

Tables in the C37 standards, on preferred ratings, are at 60 Hz. Is there a procedure to use these standards for 50 Hz applications? At first glance, I imagine a slight de-rating for the increased cycle time. Also, a close examination of the basis of the C37 decrement curves seems to be warranted.

 

[dpc]

I'm guessing you would have to get specific application data from the breaker manufacturer. I don't recall the old ANSI standards having a specific de-rating for 50 Hz. It should be lower than 60 Hz.

The newer ANSI breakers typically also have an IEC rating at 50 Hz. But direct comparisons are difficult because test procedures and test standards are the same.

 

[jbartos]

Suggestion to DPC: The test procedures and test standards are not the same in: ""The newer ANSI breakers typically also have an IEC rating at 50 Hz. But direct comparisons are difficult because test procedures and test standards are the same.""

 

[jbartos]

Suggestion: There is a trend to have the switchgear complying with ANSI and IEC standards.
The low voltage cbs are already available: Visit

http://ecatalog.squared.com/catalog/html/sections/06/17206020.htm

The high voltage switchgear are starting: Visit

http://www.abb.com/GLOBAL/ABBZH/ABB...56AEA0016F3DD/$file/LTB+Compact+B4028+Ed5.pdf

http://www.ieconsult.fr/Ansi-IECComparison.pdf

http://www.siemens.fi/evu/ev/download/peg97/pegt02i.pdf

etc. for more info

 

[dpc]

As Jbartos noted, I left out the "not" in the last sentence of my first post - meant to say that IEC and ANSI test standards are NOT the same.