GFCI Question

[palmettoinspect]

Can a GFCI outlet trip without the ground wire connected? Reson for the questions is today I had reinspection where a GFCI outlet was installed in a bathroom. The outlet tripped with the button but not the tester. The tester was showing an open groud outlet. I connected the ground wire and still got an open grounded outlet with the tester.

Thanks

[Bill Kibbel]

Can a GFCI outlet trip without the ground wire connected?

Yes.

The outlet tripped with the button but not the tester.

The button is the correct device for testing the GFCI.

[palmettoinspect]

Thanks I understand the button is the correct way to test the outlet. Are these GFCI outlets considered correct??? Even though they are showing up as ungrounded???

Thanks

[aaronm]

Can a GFCI outlet trip without the ground wire connected? Reson for the questions is today I had reinspection where a GFCI outlet was installed in a bathroom. The outlet tripped with the button but not the tester. The tester was showing an open groud outlet. I connected the ground wire and still got an open grounded outlet with the tester.

Thanks

It will still work without the ground connection. But, unless the receptacle is connected to a two-wire cable, it should not be showing an open ground condition.

[Erby]

There's lots of two wire cable still in use around here. I see GFCI on those quite frequently, though not frequently enough.

[Kyle Kubs]

Can a GFCI outlet trip without the ground wire connected? Reson for the questions is today I had reinspection where a GFCI outlet was installed in a bathroom. The outlet tripped with the button but not the tester. The tester was showing an open groud outlet. I connected the ground wire and still got an open grounded outlet with the tester.

Thanks

As Bill stated, yes, the GFCI can do it's job without the ground in place. Your tester however cannot. The typical three light tester or the Suretest have to simulate a ground fault by faulting a small amount of current to ground, so when the ground isn't present, it's like calling out to someone who isn't there...

In this case if it works with the test button of the receptacle it is fine.

The NEC [210-7d] allows an exception for replacing ungrounded receptacles with 3 slotted, grounding receptacles on a two wire, ungrounded circuit as long as they are GFCI protected (the GFCI protection does not have to be at that receptacle), the receptacle must be clearly labeled "No Equipment Ground". (They never are, as if 99% of the population would know what that meant to them anyway...) This is considered an acceptable remedy for bathrooms, kitchens and such but it still will not provide all the protection of an equipment ground in other places, like where you would plug in a television or computer, you rely on the equipment ground for static dissipation and for things like surge bars to be able to do there jobs.

Curious, what did you mean when you said "I connected the ground wire and still got an open grounded outlet with the tester"?

[hausdok]

Curious, what did you mean when you said "I connected the ground wire and still got an open grounded outlet with the tester"?

He'll answer for himself, of course; but I think he means that he found a two conductor cable with an equipment-grounding conductor, he connected the disconnected EGC, re-tested the receptacle and it still read ungrounded.

It's been my experience that, a whole lot of the time, when the EGC isn't connected at one end of a cable that it's not connected at the other end either. I see it a lot in older homes that are wired with two-conductor cable and have had new circuitry added. Folks aren't buying two conductor cable without an EGC anymore - at least not 15-amp stuff they'll use for general lighting circuits - so when they purchase and install two wire cable with an EGC in a house without equipment grounding they don't have anything to connect the other end of that EGC to, unless they bring that cable all the way to the panel. Unsure of what to do, they leave the EGC off at both ends.

Knowing that a GFCI will be tripped by a ground fault, regardless of whether or not there is a ground connected, I wouldn't have pulled the cover and dinked around with the wiring; I would have simply reported that I had an open ground on a GFCI receptacle.

If it were a pre-1962 house here, and I'd seen inside the panelboard that it was devoid, or nearly devoid of equipment-grounding conductors, I'd have assumed that someone had replaced the original two-slot receptacle with a three-slot receptacle, without including an equipment ground, and I'd have reported it as basically less-than-par but acceptable when/if the receptacles are properly labeled as required by the NEC (which is rarely done}. I'd have also recommended that they look at eventually upgrading their circuitry to a system that has equipment grounds - the sooner the better.

If it were a post-1962 house, and I'd seen inside the panelboard that there were EGC's used, I'd have reported it as an open ground that was probably preventing the GFCI from tripping with test equipment and called for immediate investigation and repair by an electrician.

ONE TEAM - ONE FIGHT!!!

Mike

[Chad Fabry]

Just my two cents: An HI should not start experimenting on the electrical system. Simply put, do not hook up wires to receptacles or anything else, just to see what happens. That is all risk, and no reward.

I heard a buzzing sound coming from a receptacle with a 500 watt halogen work light plugged into it and pulled the cover just in time to see a lick of flame. I sent the owner to basement to throw the main, opened the drywall with my fist and extinguished the plastic box and stud with water from the sink. Believe me... it was all reward.

[Bain]

Just my two cents: An HI should not start experimenting on the electrical system. Simply put, do not hook up wires to receptacles or anything else, just to see what happens. That is all risk, and no reward.

I heard a buzzing sound coming from a receptacle with a 500 watt halogen work light plugged into it and pulled the cover just in time to see a lick of flame. I sent the owner to basement to throw the main, opened the drywall with my fist and extinguished the plastic box and stud with water from the sink. Believe me... it was all reward.

Chad, I like your style.

[John Dirks Jr]

I heard that one can install a GFCI receptacle in an older house that does not have a grounded system. I understand this is never as safe as a grounded system can be. However, a GFCI receptacle in an un-grounded system is safer than a regular receptacle in an un-grounded system, correct?

The GFCI will still break the circuit far sooner than a panel breaker or fuse will.

[hausdok]

Hi,

Yes, that's correct. You can add a whole lot of safety margin to a pre-'62 house by putting either GFCI breakers in the panel or in the first receptacle in each circuit without EGC's. Depending on what type of fuse or breaker it is, it can actually take minutes to cut power. The GFCI isn't looking for an overload, it's looking for an imbalance between what's coming into the thing plugged into it and what goes out. When it senses a difference outside of its allowed parameters, it trips faster than your nervous system can react to the fault and before it can stop your heart.

OT - OF!!!

M.

[Jim Katen]

Can a GFCI outlet trip without the ground wire connected? Reson for the questions is today I had reinspection where a GFCI outlet was installed in a bathroom. The outlet tripped with the button but not the tester. The tester was showing an open groud outlet.

That's a very common scenario. The GFCI will work just fine without an equipment grounding conductor. Your tester won't test it without the grounding conductor though, as everyone else has already explained.

I connected the ground wire and still got an open grounded outlet with the tester.

Thanks

Bad idea. When you extend an ungrounded circuit, you're supposed to leave the grounding wire in your new cable unconnected. If that's what happened, you made a perfectly compliant installation uncompliant.

- Jim Katen, Oregon