Short circuit protection; ratings and settings of circuit breakers.

§ 75.601–1 Short circuit protection; ratings and settings of circuit breakers. Circuit breakers providing short circuit protection for trailing cables shall be set so as not to exceed the maximum allowable instantaneous settings specified in this section; however, higher settings may be permitted by an authorized representative of the Secretary when he has determined that special applications are justified: Conductor size AWG or MGM Maximum allowable circuit breaker instantaneous setting (amperes) 14 50 12 75 10 150 8 200 6 300 4 500 3 600 2 800 1 1,000 1/0 1,250 2/0 1,500 3/0 2,000 4/0 2,500 250 2,500 300 2,500 350 2,500 400 2,500 450 2,500 500 2,500