Weird GFCI

[Keith Runquist, CMI]

Any ideas on this. Two year old house. Kitchen GFCI tripped normally with my tester unless I was plugged into the actual GFCI. Then, no trip. The built in test button on the GFCI worked fine. Never seen this before. What would cause it?

[Bob Elliott]

Not grounded.

[Scott Gilligan, CMI]

Bingo Bob...I see it all the time.

[Joe Funderburk, CMI]

That's why you always test the actual GFCI outlet. Sometimes they show up grounded, but still don't trip. Who knows why. I write it up stating that it would not trip using a dedicated GFCI test device.

[Robert Meier]

Originally Posted by krunquist

Any ideas on this. Two year old house. Kitchen GFCI tripped normally with my tester unless I was plugged into the actual GFCI. Then, no trip. The built in test button on the GFCI worked fine. Never seen this before. What would cause it?

Does this mean that it would trip when you tested downstream devices but not the actual GFCI receptacle itself? If so, I agree with the others, the GFCI receptacle itself is un-grounded.

[Jim Port]

There is no reason for a 2 year old house to have an ungrounded receptacle.

[mnahrgang]

I know Joe said he didn't know why, but does anyone else know why that doesn't show up as ungrounded on the tester?

[Bob Elliott]

It can be set up as a false ground .
The others may actually be grounded.

[rturner]

Originally Posted by belliott

Not grounded.

A GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit. In some areas, upgrading 2 prong outlets (in older homes with a 2 wire electrical system) with 3 prong GFCI outlets is acceptable. Without a ground, a GFCI should still trip. Something else is causing it not to trip.

Some GFCI testers can simulate too weak an electrical "leak" or imbalance to trip some GFCI's.

Did it trip when you mashed the test button?

[Bob Elliott]

False ground.

[James A. Levy]

Originally Posted by belliott

False ground.

I cant believe I am about to say this but, I...I....I..........agreewithBob.

[Bob Elliott]

Originally Posted by jlevy1

I cant believe I am about to say this but, I...I....I..........agreewithBob.

Yes...Yess...Yessssssss
Join me.ha...haaa.haaaaaaa!

[rturner]

Sorry guys, I happen to disagree. The GFCI does not use the equipment grounding conductor in the sensing circuit. A GFCI will protect non-grounded circuits and according to the NEC Sec. 210-7(d), GFCI can replace two-wire (ungrounded) receptacles.

Being ungrounded should not cause a GFCI NOT to trip. However, I am still not sure why the downstream outlets will trip but not the first, and I don't see how being ungrounded or having a false ground would cause this either. Please explain!

[Larry D. Kage]

Originally Posted by Jim Port

There is no reason for a 2 year old house to have an ungrounded receptacle.

Sloppy work would do it.

[David A. Andersen]

Bob, do you think it might not be grounded?!