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Breaker kVA rating
2

Breaker kVA rating

Breaker kVA rating

(OP)
How can I calculate kVA/MVA rating of medium votage metal clad breaker?
What does kVA rating for breaker mean?

RE: Breaker kVA rating

Hi vbhagat

What other information do you have?

kVA= 1000*Volts*Current

desertfox

RE: Breaker kVA rating

It is usually the fault level rating related to the  3 phase symmetrical fault current amps at the rated voltage.   For example, a 14.4 kV breaker rated for 14,000A symmetrical fault current will be rated at 350 MVA. [(Sqrt 3)*14 kA*14.4 kV].

The rated MVA (or amps) is provided by the manufacturer, which should be equal or greater than the calculated short circuit current rating obtained by a proper short circuit current analysis of the system.

Rafiq Bulsara
http://www.srengineersct.com

RE: Breaker kVA rating

MVA-based SC ratings for circuit breakers is a deprecated method, at least in the US (ANSI C37).  Older breakers were rated on an MVA-basis.  The ratings are still seen and published, but are nominal values only.  You must use the actual kA ratings for the circuit breakers.   

RE: Breaker kVA rating

And kVA = V x A / 1000
A 100 Watt incandescent lamp is 0.1 KVA, not 100,000 KVA

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Breaker kVA rating

OH....tha old Divide by 1000 thing!

Alan

RE: Breaker kVA rating

With DPC on this one all the way

DO NOT USE MVA - ALWAYS USE kA

The energy dissipation / heat is a function of I2t








 

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