Siemens SpeedFax™ B390 Molded Case Circuit Breaker, 240 VAC, 90 A, 10 kA Interrupt, 3 Poles, Thermal Magnetic Trip
Circuit breakers provide a manual means of energizing and de-energizing a circuit. In addition, circuit breakers provide automatic over current protection of a circuit. A circuit breaker allows a circuit to be reactivated quickly after a short circuit or overload is cleared. Unlike fuses, which must be replaced when they open, a simple flip of the breakers operating handle restores the circuit.