Nec Ocpd Ratings: 450.3(A)#circuit_breaker##supervised_with_secondary
NEC Section 240.6(A) standard overcurrent protective device (OCPD) ratings — standard ampere ratings for fuses and circuit breakers
| nec section | rating amp | description | device type | location type | notes | secondary protection pct | transformer impedance pct max |
|---|---|---|---|---|---|---|---|
| 450.3(A)#circuit_breaker##supervised_with_secondary | 300 | Transformer primary OCPD with secondary protection — % of primary rated current | circuit_breaker | 250 | Supervised location with secondary OCPD; primary CB at 300% primary FLC; secondary CB at 250% secondary FLC (secondary >1000V) | 300 | supervised_with_secondary |
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240.6(A)3 rows240.86#arc_fault_circuit_interrupter#2 rows430.52(C)(1)#dual_element_time_delay_fuse#ac_squirrel_cage_design_b1 row430.52(C)(1)#dual_element_time_delay_fuse#ac_squirrel_cage_other1 row430.52(C)(1)#dual_element_time_delay_fuse#dc_constant_voltage1 row430.52(C)(1)#dual_element_time_delay_fuse#single_phase1 row430.52(C)(1)#dual_element_time_delay_fuse#synchronous1 row430.52(C)(1)#dual_element_time_delay_fuse#wound_rotor1 row430.52(C)(1)#instantaneous_trip_breaker#ac_squirrel_cage_design_b1 row430.52(C)(1)#instantaneous_trip_breaker#ac_squirrel_cage_other1 row430.52(C)(1)#instantaneous_trip_breaker#dc_constant_voltage1 row430.52(C)(1)#instantaneous_trip_breaker#single_phase1 row