Circuit Breaker Coordination Calculator

Check selectivity between upstream and downstream circuit breakers based on trip curves.

Rated current of the downstream breaker.
A
Rated current of the upstream breaker.
A
Maximum available fault current at the point.
A
Instantaneous trip multiplier of downstream breaker.
×In

Results

CB Rating Ratio-:1
Downstream Inst. Trip-A
Ratio ≥ 2:1?-
References: NEC Article 240.12; IEEE Std 1584; Eaton Coordination Guide