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Discussion Starter #1
I just purchase a house which was built in 1956 and discovered that the original 110-120 volt wiring is the old type 2 conductor with no ground wire. When the original recepticals were installed, I assume they were the type for 2 conductor wire only. But now, they all have been replaced with 2 conductor recepticals with ground lug. (the wiring was not changed).
Is this code approved? I do not believe it is.
I checked all my recepticals with a gfci tester and found 18 open grounds. I was told by my Home inspector that some of the recepticals he tested had open grounds and advised to install a GFCI on these open grounds to avoid the high expense of having the wiring corrected. So I installed a GFCI on a 2 conductor wire with no ground and tested ok when I tripped the test button. But when I purposely created a short between the hot and the grounding lug, it did not trip the gfci as expected. So what is the home inspector talking about?
There are 6 of the old type 2 conductor wiring entering the main electric panel and 6 new type romex 2 conductor with ground.
Your opinions please.
 

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A "Handy Husband"
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It is code complaint to replace 2 wire receptacles with GFCI receptacles. Down stream from the load side of the GFCI can use regular 3 prong receptacles. The receptacles should have the little stickers( included in the GFCI packaging) that say "No equipment ground".

A GFCI tester does not test by putting a short circuit (hot to neutral) on the receptacle. It tests by connecting a resistance connection between the hot and ground (a ground fault). So a GFCI wired without a ground will not trip with one of these testers.
 

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A gfci provide personnal protection, but it still does not add a ground wire.
A tester puts a high resistance short across the ground and neutral wire.
Since you do not have a ground wire, the tester will not trip the gfci.
The only test that will work is the test button on the receptacle.
The gfci should come with stickers that state no equipment ground, and these stickers need to be installed on the protected receptacles.
 

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Discussion Starter #4
My house sits on a slab and I believe there is only a carpet above it. I do not know if there is plywood in between. So in the event an appliance develops a short, Will the gfci trip?
 

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A "Handy Husband"
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My house sits on a slab and I believe there is only a carpet above it. I do not know if there is plywood in between. So in the event an appliance develops a short, Will the gfci trip?
That is not the purpose of the GFCI. It is for personnel protection not equipment of wiring protection.

If an appliance is leaking current to ground, possibly through you, the GFCI will trip.

If an appliance was a dead short circuit it will trip the circuit breaker.
 

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You're actually required to have two stickers on each grounding receptacle protected by the GFCI on the circuit without a ground wire.

1) "no equipment ground"
2) "gfci protected"

Without both, you're not meeting code.
 
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