When a GFCI outlet trips, does it open both the hot and the neutral, or only the hot? An outlet beyond the GFCI outlet has an open neutral and I wonder if that is normal when a GFCI trips?
At least three sources indicate that a GFCI outlet interrupts both the hot and the neutral.
When a GFI outlet trips off, both the hot and neutral "line" terminals become disconnected inside the receptacle from the "load" terminals.
More importantly, a GFCI receptacle switches off both the hot and neutral sides when it trips; making sure that the hot leg is interrupted even if it was mistakenly attached to the neutral side of the receptacle.
GFCI are generally designed to interrupt both conductors in case someone has mistakenly wired a circuit backwards and is using the white conductor as the hot conductor instead of the black conductor.
And this source indicates that "it depends".
Essentially RCBO's are classified by the number of poles and current paths:
- 1P+N Single pole RCBO with one overcurrent protected pole and uninterrupted neutral (two current paths)
- 1P+N Two pole RCBO with one overcurrent protected pole and an unprotected switched neutral pole
- 2P Two pole RCBO with two overcurrent protected poles
Probable, but inconclusive. You'd need to find the spec sheet of your particular model to be certain.