Originally Posted by canuk
The OP stated there is ground wiring in place ...... besides the GFCI wouldn't trip with the tester if no ground wired .... also the tester would indicate a fault ( missing ground).
Sam mentioned white, black and supposed ground wires present in his second post, and was quite precise as to the white and black being connected to his replacement GFCI receptacle, but made no mention of having connected equipment grounding conductor to a green or bare lead on the GFCI receptacle, or a green screw. Actually he doesn't mention its connection to anything at all, or being capped off, which I find potentially interesting (pun intended). He also doesn't mention having confirmed that it was in fact voltage free and a true equipment grounding only conductor for the circuit and not boot strapped, or carrying stray current.
As to a GFCI receptacle requiring an equipment ground in order to trip by a detected fault,
by intentionally pressing the test button, or that a simple plug in tester would fail to trip in test mode where no equipment ground was connected, I have not found any of those things to be the case, quite the opposite in fact. GFCI receptacles do not require an equipment grounding conductor to operate safely when wired correctly.
As to a particular plug in tester displaying a series of lights indicating a NO equipment ground as an override to a reversed wiring error, I couldn't speak to every one on the market, but I have not found that to be the case with any of the ones I have purchased or used. Actually the symptoms (power to the face when tripped and indication of wiring error when test trip button depressed) are exactly those of a reversed wiring error, when tripped in this case (non-self-testing non-lockout older gfci) load side may open, but the face is still energized, since it was the neutral or grounded conductor not the hot or ungrounded conductor which is opened. Most if not all gfci receptacles here are designed to open only the hot, unlike a gfci cordset which opens both the hot and the grounded conductor (neutral