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Mike G.
Mike G., Master Electrician
Category: Electrical
Satisfied Customers: 7650
Experience:  Proven Professional 48 years Experience
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Do you de-rate feeder conductors in addition to de-rating a

Customer Question

Do you de-rate feeder conductors in addition to de-rating a feeder conductor?
For example: If I have a 600 circuit breaker protecting a 600 amp feeder, do I derate the load alloowed on the feeder to 80% and then apply another de-rating to circuit breaker with non-continuous loads. That would make the load available of 600 x .8 x .8 = 384 amps.
Submitted: 1 year ago.
Category: Electrical
Expert:  Mike G. replied 1 year ago.

Hi, I'm Mike G and I'll be assisting you. You only derate the wire and then size the breaker to the number. The size of the breaker can be increased if the calculation shows more than the size of a listed breaker, step up to next size.