GFCI without ground

Status
Not open for further replies.
A

allbay

Member
My electrician has installed GFCI outlets without the benefit of a ground at the kitchen sink location at a 60 year old home.
The home inspector tried to trip the outlet with a tester and it would not trip. The electrician swears that this is installed according the NEC 210-7 (d) (3) b.

I am of the impression that the GFCI outlet will not trip unless there is a proper ground.

What is correct?
 
Re: GFCI without ground

GFCI outlets do not need the ground to work properly. They detect a diference between current in the neutral and hot conductors.

Testers like the one your home inspector used, on the other hand, do need the ground to work properly. The fact that the home inspectors tester would not trip the gfci receptacle in this case does not indicate that the gfci is not working properly.
 
Re: GFCI without ground

eprice,
I am also a new home builder. The private home inspector used the same etcon tester that the city building inspector uses when he test the circuits at my new construction. I have seen the city red tag outlets for improper grounding.

How does one know the GFCI circuit is functioning normally without a ground?

How do you test the GFCI outlet?
 
Re: GFCI without ground

As has been stated, a GFCI will not test properly using a plug in tester if the GFCI outlet is not grounded.

However, this does not mean that the outlet is inappropriate or inappropriately installed. It is legal to install a GFCI in an existing circuit in this manner to provide a three prong receptacle. In such a case each such receptacle should be marked "No equipment ground". However, new construction or a remodel should have properly grounded circuits.

Even with ungrounded GFCI outlets, you can still test the GFCI protection. The plug in tester can be used by temporarily connecting the ground pin of the tester to a ground source. This ground source could be a nearby water pipe (usually available easily in a kitchen or bathroom) or a ground on a grounded outlet. An adapter can be made using an adapter that converts grounded plugs to ungrounded plugs and a test clip. Or one can simply buy a GFCI tester that already has a ground lead.
 
Re: GFCI without ground

A test button is built into the GFCI receptacle for that purpose and it actually works. It throws a small resister in the circuit from the load side hot wire to the line side neutral wire. The imbalance will cause it to trip and kill power to the receptacle. If you have an older one, you will need to check the receptacle for power after tripping to make sure it is not wired incorrectly. :D
 
Re: GFCI without ground

allbay,

Yes, charlie's procedure is the one I would use in an older building were equipment grounds were not required and there is no ground to the gfci receptacle.

1) Use the test button on the receptacle to make sure it trips.
2) Then, test for power, If the receptacle was wired properly, there should be no power.

In a new building, equipment grounds are required and inspectors should red tag such a condition, because the lack of a ground to the gfci would be a code violation.

[ February 03, 2004, 01:09 PM: Message edited by: eprice ]
 
Re: GFCI without ground

As for the tester, which Etcon model is it?
FYI, not that the tester is the issue here, but the older Etcon testers were recalled.
As Charlie stated, use the test button.
A Wiggie will also trip the GFCI receptacle.
 
Re: GFCI without ground

Luke the Etcon tester that was recalled was the one for AFCI's and a wiggy will test the GFCI but at a higher current. and if the GFCI doesn't have a ground wire then a external ground source would have to be found as Racraft has already said.
I have found that if you use a three wire extention cord plug into a known receptacle that is known to be wired correctly not only can you se if the GFCI is working but also if the receptacle has been wired with the correct polarity. This is often not caught as a plug tester wont show which one is hot or which one is neutral without the ground referance. This is where bootleg grounds can be very dangerous if the bootleg ground was connected to the hot instead of the neutral. I have seen this more than once and the plug in tester will still show correct wiring. but when the home owner goes to reach for the door handle on the freezer in the garage bare foot she will know. But using a known referance to go by you can find this.
 
Re: GFCI without ground

Wayne, thanx, I realized the AFCI tester after I posted but hadn't gotten back to edit.
And I didn't read all of racraft's post. :roll: Sorry EE Bob. Todd
 
Re: GFCI without ground

ideal has come out with two types of testers for gfci & afci circuits. the cheaper version $139 will test the circuit, but the $239 unit puts a load on the system. hope this helps.
james
 
Re: GFCI without ground

still waiting how it(gfci)can detect the difference between the neutral and the hot conductor?,which has nothing to do with receptacle(gfci)working properly. GEO
 
Re: GFCI without ground

A GFCI does not require an equipment grounding condutor to operate, in fact the NEC recognizes this and allows a 2 wire non grounded recpt to be replaced with a GFCI. A gfci uses a differential current transformer to measure the difference in the line and neutral conductors, if they are different by more than 4-6 mA the GFCI trips.

Your electrician is correct, the home inspector needs to know the GFCI tester is not a mfg approved method of testing, tell him to toss it if its one of the little neon ones.
 
Re: GFCI without ground

First of all, thank you all for your replies.

Mr. Baker,
I do understand that the GFCI works without a ground.

I still think it must be improper to install an ungrounded outlet.
 
Re: GFCI without ground

Originally posted by allbay:
I still think it must be improper to install an ungrounded outlet.
Click to expand...
Perhaps I shouldn't write this without being 100% positive, but I believe it was Mike Holt's opinion that an ungrounded, GFCI recetacle outlet is the safest type of receptacle outlet that there is. While I'm not implying that Mr. Holt is an all-knowing God of elecrticity, he is the author of about 1,000,000 books on the subject!
 
Re: GFCI without ground

By Vanwalker:still waiting how it(gfci)can detect the difference between the neutral and the hot conductor?,which has nothing to do with receptacle(gfci)working properly. GEO
Click to expand...
It has all to do with the GFCI working.

I GFCI,GFP,and a AFCI all have one circuit in common. but first you have to understand how AC circuits works. when any two wires of a circuit are in close proxsimity to each other and the current on these wires are 180 deg. out of phase like it would be with a hot and a neutral and the current is eqiule one both wires, the resulting feild around the wires will very small or none at all. now the GFCI uses this effect to tell it when all of the current of a load is not being returned by the neutral (being returned by another path like earth) How this circuit in the GFCI does this is there is a little coil that they pass the hot and the neutral through it. Now as long as the hot and neutral being 180 out of phase with each other has the same amount of current on them the magnetic field from one conductor cancel's out the magnetic field from the other. this stops any current from forming in the coil there running through. now Joe the home owner is in his garage sawing some wood and there is a bad connection in the cord he's using lets say a hot to case fault and since he broke off the ground to plug it into the old receptacles that was replaced by electrican Jim :D the case no longer has a ground. So it is now at the same voltage as the hot is to earth, so Joe reaches over to pick up this saw and then leans back on a water pipe running across the front of his work bench and current begains to flow. But Jim was smart since there was no grounding conductor he installed a GFCI at the head of the circuit. now when the current running through the current coil on the hot but not on the neutral (because its returning on the water pipe) and reaches the 5 to 6 ma. level current begains to flow in the coil and actavates a circuit in the GFCI causing it to remove the power. It is this current coil that allows a gfci to work.

Vanwalker I hope this helps your understanding of how a GFCI works. This also goes for AFCI's and GFP's If I or someone else can find that web site that has a diagram of a GFCI it would probly help even more.
 
Status
Not open for further replies.
Top