[huesmann]

Gotta GFCI outlet in our upstairs hall bath that controls (protects?) another outlet that bath and the two in the master. (I assume the line runs to it and the load feeds the others.) With no change in usage, last week the outlets in the master stopped working. I hit the reset button on the GFCI and it reset, all was well.

Well, this morning, the outlets in the master were not working again. I went over to the GFCI and tried to reset but it tripped right away. I had another brand new GFCI outlet on the shelf, so I replaced it with that. Same deal. The little light on the face of the outlet briefly flashes red when it trips.

Ideas?

 

[rjniles]

You have a ground fault, open the boxes and test with a ohmmeter. you may find there is other stuff on the circuit. In older construction, they put the garage and outside receptacles on the bath GFCI

 

[huesmann]

Nope, through other incidents I know those are all on their own circuits.

Can you describe what exactly to test with an ohmmeter? Like what should be tested and what results indicate what? Thanks!

Oh, just for info this is 2002 construction.

 

[huesmann]

Well, it looks like the fault is somewhere downstream of the outlet. Disconnected the load wires and the outlet performs as expected. Will keep going downstream with connected outlets and see what happens.

 

[rjniles]

With an ohmmeter and the load wires disconnected, test from hot to ground and neutral to ground. Both tests should show open.

Sent from my RCT6A03W13E using Tapatalk

 

[surferdude2]

Nope, through other incidents I know those are all on their own circuits.

Can you describe what exactly to test with an ohmmeter? Like what should be tested and what results indicate what? Thanks!

Oh, just for info this is 2002 construction.

One way to test for a ground fault using an ohmmeter on a downstream protected NM cable run is to disconnect the downstream neutral conductor at the GFCI receptacle box. With power off, check the resistance between the hot and ground and also between the neutral and ground. Anything other than infinity is considered a fault.

 

[seharper]

Well, this morning, the outlets in the master were not working again. I went over to the GFCI and tried to reset but it tripped right away. I had another brand new GFCI outlet on the shelf, so I replaced it with that. Same deal. The little light on the face of the outlet briefly flashes red when it trips.

Ideas?

Firstoff, you don't have a ground fault. Remember the Golden Rule of GFCIs: Ground faults only happen to other people. MY appliances are fine; it's the GFCI's fault somehow!

Seriously, though, you already blew right past the most basic 3 tests for a GFCI when it trips.

1. Unplug everything and see if it still trips.
2. Identify the downline and unplug everything there, and see.
3. Remove it from the wall and remove everything from the LOAD terminals. Everything including neutrals.

If it still trips after #3, into the trash it goes.

Otherwise the GFCI is fine. You're "other people" It's the wiring, or hardwired appliances. (Which we know because we eliminated the plug-in appliances in steps 1-2). Then you go 50% of the way down the downline, sever hot AND NEUTRAL there (turning off power in between, obviously!) and re-test. Now you know which half the problem is in. Divide that half in half, rinse wash repeat. At some point, removing one thing will make it stop tripping. *cough*bathroom fan*cough*

You have a ground fault, open the boxes and test with a ohmmeter. you may find there is other stuff on the circuit. In older construction, they put the garage and outside receptacles on the bath GFCI

Oh yeah, anything like that!

With an ohmmeter and the load wires disconnected, test from hot to ground and neutral to ground. Both tests should show open.

Low resistance to ground is conclusive. Showing open is not conclusive. Many insulation failures are voltage-sensitive, that's why megaohmmeters are a thing. (they shock the circuit with 125, 250, 500 or 1000V).

 

[huesmann]

Firstoff, you don't have a ground fault. Remember the Golden Rule of GFCIs: Ground faults only happen to other people. MY appliances are fine; it's the GFCI's fault somehow!

Seriously, though, you already blew right past the most basic 3 tests for a GFCI when it trips.

1. Unplug everything and see if it still trips.
2. Identify the downline and unplug everything there, and see.
3. Remove it from the wall and remove everything from the LOAD terminals. Everything including neutrals.

If it still trips after #3, into the trash it goes.

Otherwise the GFCI is fine. You're "other people" It's the wiring, or hardwired appliances. (Which we know because we eliminated the plug-in appliances in steps 1-2). Then you go 50% of the way down the downline, sever hot AND NEUTRAL there (turning off power in between, obviously!) and re-test. Now you know which half the problem is in. Divide that half in half, rinse wash repeat. At some point, removing one thing will make it stop tripping. *cough*bathroom fan*cough*

You are absolutely right. I just happened to have a brand new outlet on hand so my brain went there first.

 

[NCmountainCabin]

either:
- the GFCI outlet is still sensing the condition that continues to 'trip' it
- you have no power to the GFCI outlet, via the main panel's breaker for this circuit
- the GFCI outlet is 'bad', although since you already replaced it, that's doubtful
- wiring within the GFCI from the circuit has issues, such as a 'short'