[kkenney79]

How do you install GFCI Recepticles properly with old wiring in a house?

[tkrussell]

How much detail do you need? Do you need help with where the wires connect? Have you tried reading the instructions? What type of "old wiring" do you have?

Do you have a voltage tester? You may need one to determine the hot wire and neutral, as they must connect to certain terminals on a GFI outlet.

[kkenney79]

How much detail do you need? Do you need help with where the wires connect? Have you tried reading the instructions? What type of "old wiring" do you have?

Do you have a voltage tester? You may need one to determine the hot wire and neutral, as they must connect to certain terminals on a GFI outlet.

My wiring only has two wires there is no ground wiring is that a issue with ground fault recepticles?

[omzig]

Actually code does permit using a GFCI receptacles without an equipment ground. Such receptacles are supposed to be labeled "No Equipment Ground." GFCI receptacles usually come with a sticker that says this.

As tkrussell mentioned, you have to make sure that you know which wire is hot and which is neutral, and connect the correctly or the GFCI won't work. Sometimes with old wiring it's hard to tell the color of the wires and sometimes they are both black. I used to own a very old house that was wired so long ago that I think it my have been done by Ben Franklin. Everything was wired with no regard for what was hot or neutral and all of the wires were black (or bare :eek: )

[tkrussell]

Exactly as omzig says, since there are many older homes wired with the two wire romex, called Loom cable, and the even older Knob and Tubing, protection can be provided by using GFI outlets.

This can be one new GFI outlet at each outlet being replaced, if there are only two wires, and if there are four wires because the circuit continues into other outlets downstream, the new GFI can protect those also.

Each outlet, including the GFI and any other new three wire outlets that do not have a ground, must be labeled with the "No equipment Ground" and "GFI Protected" stickers.

This by the way, is the only way any two wire receptacle can be replaced with a three wire device. If not protected with a GFI, any two wire outlet must remain two wire device, cannot just replace with a three wire.

The challenge is to determine which wire is hot and which wire is neutral. The Loom cable usually did have black and white wires, may be discolored from age that makes it hard to tell. K&T wiring is only black. Must be absolutely sure which is which.

Not having a ground is allowed only if the outlets are two wire, and can be changed to three wire only if the circuit is protected by a GFI. Any GFI will continue to work since it does not need an equipment ground to function properly.

When they wired 2 wire circuits, polarity was not so important, this is why the outlets had both blade openings the same size. At some point outlets were then made with the neutral blade larger than the hot, both 2 wire and 3 wire outlets. Now, definitely polarity is important and needs to be correct.

So, you probably are wondering, since you have two wires, both are black, and unable to tell which is hot and which is neutral. And without a ground at the outlet, a standard tester or meter is useless, unless you extend one lead with a long wire that is grounded at a water pipe, sink, something in the home that is normally grounded, then use the short lead to test each wire.

There is another way using another type of tester, the old fashioned cheap Neon light tester.These are still sold in hardware stores for a buck or two. What I am about to tell you I have never mentioned here, and some people may freak out, but this method works, it is perfectly safe, and many electricians do not know this method.

MUST BE A NEON TESTER, hold one tester lead between your fingers, yes holding the metal of the test probe, use the other lead to touch to each of the wires one at a time. Only one wire will cause the neon light bulb to glow very dim. The other will have no effect. The wire that caused the tester to glow is the hot wire.

The current is very low, the resistance is high,and the neon bulb only needs you as a ground to glow. You will not feel anything, no tingling, nothing. Of course, taking reasonable common sense precautions, and don't do this soaking wet, or bare feet, etc.

Once you have determined the hot wire, any hot wire needs to connect to Line brass screw on the GFI, label the other wire with white tape and connect to the LINE silver screw terminal on the GFI.

Now if you will protect any other outlets downstream, because you have two wires in a box and two wire out, those wires connect to the LOAD terminals, and if the outlets are two wire polarized, with one blade wider than the other, then must be sure of hot and neutral on those also, and connect the hots to the brass and the neutrals to the silver terminals.

And label "No Equipment Ground" and "GFI Protected". This is so if someone comes along with a three wire plug, they are informed that they will be GFI protected but there is no ground.

If there is something I missed or you do not understand, get back with those questions.

[omzig]

Awesome answer as usual tkrussell!

When they wired 2 wire circuits, polarity was not so important, this is why the outlets had both blade openings the same size. At some point outlets were then made with the neutral blade larger than the hot, both 2 wire and 3 wire outlets. Now, definitely polarity is important and needs to be correct.

Polarity didn't matter much for receptacles back then, but this disregard of polarity sometimes led to wiring switches on the neutral side, which can be pretty dangerous if you start working on a light fixture with just the wall switch turned off. Not that this has anything to do with GFCI outlets, but it is something to look out for, espescialy with old wiring.