Hi all,
I just finished replacing a bathroom receptacle with a GFCI in a 200 year old house. My Sperry Instruments GFCI tester tells me that I have an open ground. The GFCI protected light and switch work normally, i.e the light turns on. I am certain that the issue is that there is no ground wire coming up from the service panel. Am I cooked?
Replies
My understanding is that a GFI will work without a ground. I dont know if you'll be cooked or not, but I believe the GFI will work.
I'm sure Bill Hartman will be along soon to answer this.
Thanks. And you were right about Bill Hartman
You do not need a ground for the GFCI to work correctly.
In fact the code allows 2 prong, ungrounded receptacles to be replaced with grounding style (3 prong) if they are GFCI or protected by an upstream GFCI.
However, in that case they are to be labled NO EQUIPMENT GROUND. Such labels are in individual packaged GFCI's.
This is all for older wiring systems that don't have a ground.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Edited 10/22/2007 7:55 pm by BillHartmann
Thanks alot.
Bill,
Let me just say how much we all appreciate your sage wisdom and expertise. Your input over the years has really been invaluable.
Greg
Bill, my buddy says his electrician friend advised him to replace the ungrounded outlet where his computer is plugged in with a GFCI and to pigtail from the GFCI ground terminal to the white wire. Does that make sense to you?
BruceT
Right. And if my checking account is overdrawn, then I write a check to cover the deficit.
Ed
my buddy says his electrician friend advised him to replace the ungrounded outlet where his computer is plugged in with a GFCI and to pigtail from the GFCI ground terminal to the white wire.
That won't protect the computer equipment - you need a real ground to protect the computer equipment.
Without a try ground you won't get full surge protectionThere are all kinds of surges. But I don't know if connecting the ground to the neutral or leaving it open which would protect againts most sureges.However, bugging the ground terminal to the neutral introduces it's own problems.With some failure the case could become hot..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Like Bill said. The only downer is that items requiring surge protection are not protected (equipment wise). The surge protectors send the surges to the egc (which is not there in this case) as I understand it. For a bunch of stereo/home theater/computer stuff I would run a correct ground wire IAW code requirements.
edit: this was for other applications, doubt if that type equipment would be in the bathroom (;-)
Edited 10/23/2007 10:40 am ET by rasconc
Thanks for getting back. Indeed the only downstream item is the vanity light which should noy have any surge type problems. As Bill pointed out I was very glad to learn that GFCI are an acceptable alternative to the old 2 wire system. You learn something new every day and this was it. Thanks again for your help.
The other thing is that you should not put a freezer, refigerator or sump pump on a GFCI, grounded or not.Too much possibility of false trip.The should be on a true grounded circuit, even if that means fishing some new circuits..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Right again, I forgot to add that. I am just happy you did not have to correct me(;-), just add on.
Bill,
What about dishwashers and garbage disposals that have cord and plug with the outlet in the sink base? Mine will each be on its own circuit.
I am assuming that they don't really need a GFCI. Is there a probability of a nuisance trip if they are on a GFCI?
I replaced our dishwasher a year ago with one that required an outlet (Miele brand). So I installed a box and put in a GFCI receptacle just to be safe given proximity to water.
Hasn't tripped yet.
P.S. I'm not an electrician.
By code the you only need the GFCI on receptacles that serve the counter top.And as a practical matter the GFCI does not add any safety a DW or GD.It those are ground through the cord end receptacle. And you aren't drop one in a sink will it is plugged in.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
If the surge protectors send the surge to the egc, would that cause a GFCI upstream of the surge protector to trip?George Patterson
Past my knowledge level but do not think so. IIRC the fault tends to want to go to ground, GFCI is comparing current hot vs neutral. Defer to the many gurus to be found here.
Bob
Maybe, maybe not.But the GFCI might not even "see" the surge as they can be very high frequence.And I know that the GFCI does not trip fast enough to prevent load from being damaged from a surge..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.