13.8Kv Breakers Currents Rating 2

[Okpower]

Hi all:

I am looking for information about the main comercial current ratings of vacuum breakers for 13.8 KV (prices will be excellent too). I need to feed eight areas (3 to 6 MVA each) of a plant in 13.8 KV, but i dont want to use 1200 A breakers, that seems to be the most common rating, but 1200 A seems to be too much for the mentioned Power.

Thanks

 

[rcw retired EE]

1200 Amp is a standard size for NEMA breakers for switchgear. I am not aware of any manufacturer if 400A, 600A or 800A 15 kV class switchgear breakers. Most of the cost of the breaker is in the frame, mechanism and enclosure. Dropping to 600A would not save much money.

 

[trosepe]

If you are OK with SF6 filled units; look at the S&C Vista line. I have been using them for 10 plus years with no problems. They are available with upto six interrupters per enclosure with 200 and /or 600 amp ratings. They are self powered and use SEL made relys integral to the unit.

 

[dpmac]

I agree with trosepe, I had the opportunity to play with some new S&C Vista switches this week. They are a nice unit and should definitely be considered.

 

[Zogzog]

I have some 15kV GE V1B 600A, Toshiba 15kV VP 600A, and a bunch of Westinghouse 15kV V 600A breakers in a NEMA 3R enclosure, but they are rare birds.

1200A is more common, you may save a little up front getting a 600A breaker but finding parts, spares, etc.. in the future will be difficult and expensive.

Stick with the more common stuff, will make your life easier in the future. I have a ton of new/surplus 1200A 15kV stuff from all OEM's, can build your sub to your spec in a few weeks.

 

[mmt019]

OKpower, I assume you want the ability of programming a curve into a trip unit. On that assumption, the equipment type depends upon the location where this is going. If the application calls for indoor use, just go with the standard metal-clad drawout switchgear with 1200A breakers through-out with draw-out type relays. That will provide you a means of testing your breakers and relays without much down-time. I'm familiar with the S&C Vista but only as an outdoor pad-mount or underground vault type application and is not drawout equipment. Square D, Cutler-Hammer, GE, Siemens, ABB all make good metal-clad. There is my $.02 worth. Good luck.