Relay pickup above breaker continuous rating allowed

[chuckd83]

In the medium voltage world, we set our pickup above equipment ratings to allow the customer the flexibility of temporary overloads. We protect against short-circuit and not overload.

For cable, this is allowed per NEC 240.101(A).
For transformers, NEC Table 450.3(A).

Is this discussed anywhere with respect to the breaker itself (setting the pickup above its continuous rating)? I've looked through the Red Book, Buff Book, ABB T&D book.

 

[dpc]

Before UL got involved, low voltage power circuit breaker trip units could be set at 110% of their continuous rating. But UL doesn't allow that for either LVPCB or MCCBs. Not sure about specific language in the NEC.

 

[wroggent]

C37.010-2016 and C37.20.2-2015 discuss short-time loading of breakers and switchgear. Also see NEC 490.21(A)(4)(1).