Switchgear MVA and current rating question
Switchgear MVA and current rating question
(OP)
We have an old Reyrolle S36A circuit breaker which the specs say is rated at 11KV 800A 500MVA. Just doing the math with these numbers they don't seem to add up. From memory VA = Vline x I x root 3. If you put the numbers in it seems like the breaker is rated at: 11000 x 800 x 1.732 = 15.24 MVA and not 500MVA as stated in the specs. Am I missing something?
Cheers
Cheers






RE: Switchgear MVA and current rating question
RE: Switchgear MVA and current rating question
Thanks
RE: Switchgear MVA and current rating question
For example, the calculated MVA interrupting capacity for the 350 "MVA class" is typically 338 MVA rather than 350 MVA.