I am reviewing a vendor drawing and I think they undersized the circuit breaker for this project.
The CB is the 460Vac feeder CB and is 600 Amp.
It feeds the following:
1) RV Soft Starter for a 400HP 3P ac motor, FLA=432A, LR=6.28x, 1.15 SF load = 498 A, NEC 430.250=477 A
2) 30 Amp CB for a 15HP motor, 21 FLA
3) 3 Amp CB for a 0.75 HP motor, 1.6 FLA
4) 2 Amp CB for a 0.5 HP motor, 0.9 FLA
5) 6 Amp CB for a 3 KW resistive heater, 3.8 A
6) 4 Amp CB for a 480V/120V transformer that feeds a 200W heater and 150W of lighting
Am I right to tell them that the 600 A CB is too small?
The CB is the 460Vac feeder CB and is 600 Amp.
It feeds the following:
1) RV Soft Starter for a 400HP 3P ac motor, FLA=432A, LR=6.28x, 1.15 SF load = 498 A, NEC 430.250=477 A
2) 30 Amp CB for a 15HP motor, 21 FLA
3) 3 Amp CB for a 0.75 HP motor, 1.6 FLA
4) 2 Amp CB for a 0.5 HP motor, 0.9 FLA
5) 6 Amp CB for a 3 KW resistive heater, 3.8 A
6) 4 Amp CB for a 480V/120V transformer that feeds a 200W heater and 150W of lighting
Am I right to tell them that the 600 A CB is too small?