Siemens B370GFHH GFCI Molded Case Circuit Breaker

The 70A rated current is the basis for coordinating this breaker with the circuit load and conductor ampacity. Evaluate the load and applicable circuit-sizing requirements rather than treating the rating alone as permission to carry any 70A load continuously.

The breaker is rated for 208Y/120VAC, 3-phase service and has 3 poles. The Y voltage rating refers to a wye system, so match both the system voltage and phase configuration when selecting it.

The 65kAIC rating describes the breaker's ability to interrupt fault current at its rated voltage. Available fault current at the installation point must not exceed that interrupting rating.

GFCI protection responds to a current imbalance indicating leakage to ground. Select this feature when the circuit requires ground-fault protection in addition to overload and short-circuit protection.

The thermal and magnetic trip settings are fixed, not adjustable. The thermal element provides long-time overload protection, while the magnetic element provides instantaneous response to short-circuit current, so selection must account for the circuit's operating load and starting current.

The pigtail neutral requires a connection to the system neutral. Include that connection in the installation wiring plan for the GFCI breaker.

Use the 60/75 °C conductor temperature rating when selecting conductors and applying the appropriate ampacity rules. Coordinate conductor insulation ratings and termination temperature limits rather than relying on insulation temperature alone.

The load-side connection uses a lug, so the outgoing conductors terminate in the breaker's load-side lugs. Plan conductor preparation and termination for a lug connection.