GE Type FKR-255-150 Circuit Breaker 3

[davidbeach]

I am looking at a photo of the name plate of a GE Type FKR-255-150 Circuit Breaker, and I can see all sorts useful data, but no interrupting rating. The instruction manual is a GE GEI-11313. Google doesn't turn up anything of value except people wanting to sell used ones.

What I want to know is the interrupting rating. From the age of the breaker I'd guess it is going to be an MVA rating. Can anybody confirm a rating, preferably from a scan of GEI-11313?

Thanks.

 

[alehman]

Maybe try this. It looks like you need to create an account to access it.

http://www.electricalmanuals.net/in...pment/BREAKERS/GE/FKR/GEI-11313T/View-details

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.

 

[davidbeach]

Thanks, nice reference. Unfortunately the instruction manual, now that I can look at it, doesn't list ratings. It indicates that there are ratings of 100, 250, and 500MVA, but provides no guidance in determining what a specific breaker might be (any way from skimming through the manual, I haven't read all 28 pages.

 

[rbulsara]

A couple of those websites of used equipment list FKR-255-150 as 150 MVA 600A, 15 kV. It seems reasonable as FKR-255-250 is described as 250 MVA. Apparently they were available up to 1200A and 1000 MVA.

See

http://uen.hsix.com/q/webinv/000920=p,2420,0C2245,,list,,,20037499,,

Rafiq Bulsara

http://www.srengineersct.com

 

[Zogzog]

David, the 150 in the type means 150 MVA, pretty weak. While we don;t deal with OCB's we do build VCB replacements for these with higher ratings.

 

[dpc]

David,

Attached is from the standard library in EasyPower. I'm not sure if the "A" suffix has any significance in the SC rating. I'm also not sure of the primary source of this data, but they generally don't make it up. I can ask Chet for a reference on this if it is critical. Let me know.

I don't find it in Conrad's book.

dpc

David Castor
www.cvoes.com

 

[davidbeach]

Thank you, thank you. Only 150MVA? Ouch. I know where I don't want to be if there is ever a fault in the wrong place.

 

[Zogzog]

Yep, had some 25-'s fail this week and they found out the hard way the importance of proper ratings and fault currents. Big booms.