GFCI used to stay tripped for many hours, now fully dead

Question

Electric Panel---20A Circuit Breaker---GFCI (Kitchen)----Load1---Load2---Load3---Load4

The first floor wall on which GFCI and Load1,2,3,4 installed was affected by laundry water very minor leakage about a year back. Resetting the GFCI solved that problem twice. 2 months back the GFCI tripped and was not getting reset right away. It would take a day or 3 days to get the GFCI reset again. That time only load connected is a small table top microwave in Load1 socket. Load2-4 were empty and will be used for Juicer, rice cooker etc when needed. But all were disconnected.

Assuming the Microwave load may be tripping it, i removed the microwave. So no load device connected now. The recent GFCI tripped never restored.

So far, I have removed and checked Load1,2,3,4 connections. No signs of burning or loose. I have replaced GFCI twice. I have also replaced the 20A Circuit Breaker in the Panel.

Problem is still no power to GFCI or load now.

I further removed GFCI's Load side wires (neutral and Hot). The ground of incoming to GFCI and outgoing to Load is connected by a crimp, so I could not separate that. Tested 115 voltage between incoming Hot and neutral wires on the screw. But no led light on GFCI or no lower in GFCI socket when a lamp plugged in. GFCI tester shows no lights.

The GFCI tester shows no lights at all. (It used to show fault or all good earlier).

I am electrical engineer (many many years back, but worked in IT, Instrumentations and SCADA and I am quiet technical as well handy). It is frustrating not able to debug this.

Any tips before I throw my hat and call somebody? What should I test? (I have many types of testers) Connecting back the microwave will show different symptoms? One of the Load if having a loose neutral, will that show no power on GFCI outlet itself?

Answer 1

It's not entirely clear what's connected to the receptacle when you replaced it and tested it, although you did say "I further removed GFCI's Load side wires". I suggest connecting only the 2 line wires and the ground to simplify the situation. If you get, as you said, 115 V hot to neutral on the screws and the receptacle reset button is not working, then either you have the wrong screws connected, didn't fully press the reset button, or the receptacle is broken or defective.

Don't worry about the other 4 outlets until you know the GFCI is working normally.

Edit: In your answer that you posted today, "When i measure the voltage at GFCI, it was 120V Ground-Neutral". This indicates you have an ungrounded neutral wire, possibly connected to a hot wire somewhere between the GFCI and the panelboard. (At another receptacle, as you said). If the hot and neutral wires both have 120 VAC to ground, then the GFCI may not reset due to incorrect wiring.

Answer 2

Finally I am able to solved this issue. This is the configuration I described earlier.

Electric Panel---20A Circuit Breaker---GFCI (Kitchen)----Load1---Load2---Load3---Load4

But I forgot to mention that there were 3 more wall sockets connected in parallel to the GFCI.

same 20A Circuit Breaker-----GFCI----Load1----To ---Load4

same 20A Circuit Breaker------Wall socket1

same 20A Circuit Breaker------Wall socket2

same 20A Circuit Breaker------Wall Socket3

So basically when CB is switched off, the GFCI and 3 wall sockets will loose power. After removing the Load side all 3 wires from GFCI, i noticed that it was still stayed tripped. So whatever coming to GFCI was not good. When i measure the voltage at GFCI, it was 120V Ground-Neutral and 120V Ground-Live. SO it meant something incoming was wrong. Then i used GFCI socket tester on all sockets to see what is happening. One of the Wall socket showed Ground fault. I replaced that wall socket itself ($3) and problem solved.

To be noticed, this bad socket has lots of green rust that comes on socket connections. also This socket is right behind the water shut off valve in the wall. I have never seen mold or wetness on walls but it could be little more inside the walls.

any way, problem solved. That wall socket was not much in use. But my wife once mentioned few months back that, she was not getting power for laptop when connected to that socket. I remember ignoring that assuming she did not pushed the cable enough.
Next time I will use GFCI tester on all the sockets for that Circuit Breaker, (before changing the Circuit Breaker in the Panel).

So what I have learned from this and for others who are interested in solving other GFCI issues.

1. Read the Circuit breaker panel. Mine says Kitchen "GFCI and Dining area" for that Circuit Breaker 16.

2. I Should have tested just the GFCI (disconnect all 3 wires from Load). If GFCI still can not stay ON, that means other wall circuits on the same Circuit Breaker could be bad.

3. a standard $10 GFCI tester with 3 lights is good enough to know if the wall outlet is good or not. I also wiggled the GFCI tester just to know that there is no loose connection inside.

Excited enough, i ran the GFCI tester on many of my other wall outlets just to make sure similar issues are not creeping up elsewhere. The house is about 17 year old.