opes

Main Circuit Breaker

Discussion created by opes on Oct 30, 2018
Latest reply on Oct 30, 2018 by chiefns830

What is the proper method of sizing the main service circuit breaker? The method I use is 125% of the continuous load plus the sum of the noncontinuous loads.  [300ampX1.25] + [400amp] = 775A or 800A main. Some AHJ's are requiring a 100% rated circuit breakers. For 775A load that would be a 1000amp circuit breaker. Any thoughts?

Outcomes