SIEMENS QF240A Circuit Breaker 40A 2 Pole 120/240V AC

SIEMENS QF240A 40A Ground Fault Breaker

The SIEMENS QF240A is a 40A two-pole miniature circuit breaker rated for 120/240V AC single-phase service. It provides Class A ground-fault protection with a 5mA trip threshold and a 10kA interrupting rating at 120V AC. The plug-in design fits compatible Siemens load centres and accepts 8 to 6 AWG copper conductors via lug terminals. Its frame size is rated at 225A.

Suits panels needing 5mA ground-fault protection

This breaker serves circuits where personnel protection against ground faults is required by code, such as bathrooms, kitchens, garages or outdoor receptacles fed from a Siemens load centre. It will not suit installations that demand standard overcurrent protection only, panels from other manufacturers, three-phase distribution systems or DC circuits. Buyers needing a higher interrupting rating or a different mounting style should look elsewhere.

Sustained load performance with 10kA interrupting

Under continuous loading the device operates within its 40A thermal rating while the ground-fault sensor monitors leakage current at the 5mA level. The 10kA AIR rating at 120V AC ensures safe interruption of available fault current on the protected circuit. The toggle actuator provides a clear visual indication of tripped status after an overload or ground-fault event. The plug-in mounting maintains secure contact during thermal cycling.