Will a QO or Homeline GFI, AFI, CAFI, or DF circuit breaker be fully operational in a panelboard or load center that does not have a neutral bar?
Does the correct operation of a GFI breaker require a line neutral?
QO, QOB, and Homeline breakers
Miniature Circuit Breakers
No, QO and Homeline electronic circuit breakers will not be fully functional in a panel without a neutral.
Whether GFI, AFI, CAFI, or Dual Function, QO and Homeline electronic circuit breakers require a 120V source for their push to trip/test feature to operate correctly. This means a neutral must be present in the system AND must be tied to the breaker through the white pigtail wire or plug-in neutral connection. This is required EVEN IF there is no neutral present in the load.
For more information on how the electronics in a GFI breaker work, see FA115047.