Chris Lewis wrote:

According to Jay :

GFI outlets do not work without a proper ground. (The "test" button
trips them, but the plug in tester will not). I know this because I
failed a CO because a GFI was on an ungrounded circuit (knob and tube).


The inspector was either ignorant of the NEC, or, you misunderstood why
you failed inspection.

The NEC (and CEC) _explicitly_ approves GFCIs on ungrounded circuits for
renovation/repair work if you don't have a real ground.

They work just fine without grounds.

OK. Let me correct this. The "tester" failed to trip the GFI. Maybe
it would work if you jammed a fork in the slots or something. I wasn't
about to argue with the Code Inspector for a $10 fix.

Jay