GFCI stopped working... not defective

407 Views 7 Replies 4 Participants Last post by surferdude2, Feb 16, 2020

MrMeasureTwice

Discussion Starter · Feb 15, 2020

After 18 years in this house I had a GFCI outlet just stop working.
Did not pop, and tested regularly.
Press test button, nothing, press reset, nothing. Not daisy-chained, has it's own 15 amp breaker at the panel.
With circuit breaker closed, there is 120 at both white and black wires when checked against ground.
Bought new one, no joy.
Installed a plain outlet - still no joy.

BAFFLED. :vs_mad:

Save

1 - 8 of 8 Posts

viper

· #2 · Feb 15, 2020

Sounds like you have another GFCI in series somewhere. First thing is to remove recep cover and test wires directly. If no joy, you need to start looking. Power at the main breaker but no power at the recep wire mean open somewhere.

I also commonly see the stab terminals used on receps in which they will burn up and open anything in series. I NEVER use them and always use the screw terminals on receps.

Save

surferdude2

· #3 · Feb 15, 2020 (Edited)

It those measurements were at the receptacle, sounds like you have an open neutral. Since you're getting a voltage reading on the neutral, it must also be either a shared neutral (2 phase ) with some load connected on the other phase or else some load is connected to the phase you are working on that you may not be aware of. Check at the panel first for a loose neutral and then it's a matter of taking affected receptacles apart to find the loose or burned neutral.

Check other receptacles based on what the panel label says the breaker is serving to find any that are not working. Use some actual 120 volt device to load test the receptacles... a lamp or drill motor, etc.

Save

MrMeasureTwice

Discussion Starter · #4 · Feb 16, 2020

Thanks Viper & SurferDude2 - it seemed weird that the neutral showed 120v at the wire in the box where I pulled the outlet/receptacle.

I'm not sure how to trace it back though - the breaker is labeled MBA Plug (Master Bath) and it is the only one in there. I suppose it could be the end of a series of outlets, so maybe using a fox-and-hound (tone generator) with the breaker open to find out where it might be getting fed from?

Just seems odd, but not surprising, that the breaker is labeled as if it only for that outlet, but this house was built 30 years ago and who knows what they really did vs. the label on the breaker.

Save

joed

· #5 · Feb 16, 2020

Could be the neutral connection in the panel, either the breaker to the bus bar or the cable to the breaker.

Save

surferdude2

· #6 · Feb 16, 2020

Tip. Something else is connected to that circuit or else the neutral wouldn't have any voltage. It is getting voltage from the hot line through some load and onto the neutral. That means there is some other circuit that is also dead. Test all receptacles.

Save

Reactions: 2

MrMeasureTwice

Discussion Starter · #7 · Feb 16, 2020

Yep, SurferDude2, that makes sense to me.

A hunting I am going... :gunsmilie:

Save

surferdude2

· #8 · Feb 16, 2020 (Edited)

It has to be something that is on all the time. Night light, clock, wall wart transformer, door bell transformer, spare rarely used TV (yes, they require power to run the remote receiver), etc.... Something that's usually on all the time isn't working now... that's a clue to consider.

Don't rule out any the fact that the receptacle may get power from the ceiling light/fan junction box or the switch box that serves them.

We must not permanently discount the fact that you may be using a high impedance test meter and the voltage you are reading on the neutral is a result of capacitance coupling of the cable conductors running next to each other in the sheath. You indicated a full 120 volts being present so I discounted that for the moment. Doesn't change things... would still be an open neutral.

See less See more

Save

Reactions: 1

1 - 8 of 8 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month