arc energy reduction

[GG1964]

If a circuit breaker frame size is 1200 A, with a 1000 A trip plug installed, is required to have a means of arc energy reduction?

[Manon_Chaboud · Accepted solution]

Hello @GG1964 , thank you for your question.

Yes, when a circuit breaker frame size is 1200 A, and a 1000 A trip plug is installed, it is advisable to have a means of arc energy reduction. This is important for ensuring the safety of the electrical system and personnel in the event of a fault. The goal is to minimize the potential arc flash energy to protect people and equipment. 

[GG1964]

Your response states, "it is advisable to have a means of arc energy reduction". 

I'm trying to determine if it "is required" per NEC Art 240.87 which states "Where the highest continuous current trip setting for which the actual overcurrent device installed in a circuit breaker is rated or can be adjusted is 1200 amperes or higher, 240.87(A), (B), and (C) shall apply.".  I could interpret this that a 1000A trip plug in a 1200A frame breaker is below 1200A and therefore does not require arc energy reduction.