AnsweredAssumed Answered

NFPA 70E Annex D

Question asked by rene.immerkaer on Apr 15, 2020
Latest reply on Apr 16, 2020 by fourseng

Hi.

 

For arc flash calculations in equation D.4.2 Arching current, bolted three-phase available short-circuit
current (symmetrical rms), is used.

Can anyone tell me the definition of "bolted three-phase available short-circuit
current"?

In my case I have 65kA short circuit current directly from the terminals of my transformer. But the location of my arc flash incident is downstream to CB limiting the current to 15kA.

What should I consider as input for the arching current calculations?

Thanks in advance

Outcomes