Electrician Question

[Bill Bowman]

Is it possible to determine if ground fault outlets are wired properly, without having the power on??? They're new outlets, so I would assume they are functional, but is there an accepted method of checking the wiring with a meter, to assure the wiring is correct?? Thanks. Bill

 

[Aceman]

You can check the wiring by doing a visual check and seeing where the wires are landed. Whether the GFI will work properly can only be determined when it's powered up.

Black wire-brass colored screw
White wire-silver colored screw
Ground wire-green screw

If the recep is line-loaded(receps downstream are GFI protected through this recep) make sure the feed-in lands on the bottom(line) and the feed out lands on the top(load).

 

[Charles (in GA)]

After it is powered up, you can use a plug in tester with LED's that will show if it is wired correctly or not. The better ones have a button on them, press it to create a ground fault to trip the GFCI, same as the internal test, but you can use this one down stream to verify that those receptacles are actually protected by the GFCI.

I used mine the other day on the (new to me) scissor lift I purchased. They have a receptacle on the work platform, you plug in at the bottom of the lift, saves extension cords hanging over the side. Turns out it was wired backward, hot and neutral crossed, indeed it was when I opened up the Bell box it is mounted in.

Charles

 

[ddawg16]

Ace is correct.

I believe you can buy a test device that will force a ground fault to test the GFI.....it's just a dummy plug that plugs into the outlet. It effectively does the same thing as the test button on the GFI....assuming it is working correctly.

here is one of many decent articles that explains how a GFI works.

 

[Flatmotor]

I use the Hubbell GFT2G 2-7ma range. They work great but kinda pricey. I bought some replacements for my crew about a month ago and they were about $85.00ea. Bill

 

[Aceman]

Since so many people have mentioned the use of the plug-in GFI tester, it should be noted that they do not work on GFI's installed on 2 wire systems(i.e. no "ground" wire). Manufacturers recommend using the "test" button as the proper way to check the devices.

 

[kbs2244]

Isn't a 2 wire system always a "ground fault"?
Or are you talking about a conduit as ground system?

 

[Charles (in GA)]

A GFCI is quite legal to use on an old two wire system like you would find in a 1950's house for example. You do have to label it that there is no ground. A GFCI simply looks at the current going out and the current coming in, and if they are not the same, it trips the breaker in it. The handheld plug in tester depends on having a connected and functioning ground, as it bleeds off some of the outgoing current to ground to create the fault, so, if the ground pin were not connected to anything (as in a typical residential two wire system, prior to todays three wire) then it would not trip the GFCI. I'm not sure how the tester in a GFCI receptacle creates a fault, I'm guessing they use the neutral, before the current sensing device (right at the incoming neutral terminal), it would give you the same effect as a fault to ground.

Charles

 

[roofster]

I have a new to me 50's house and the outlets are a two wire system. There are no GFI outlets anywhere so I'm thinking about using GFI breakers. Would they work or am I better of with GFI recepticles?

 

[Charles (in GA)]

It shouldn't matter. The Leviton GFCI receptacles I have bought have instructions on installing them in a two wire system with no ground, and the GFCI breakers merely replace the old breaker and have a wire going to the neutral/ground bar.

Is your panel new? At least new enough that you could buy GFCI breakers to fit it?

Charles

 

[MAD]

I have a new to me 50's house and the outlets are a two wire system. There are no GFI outlets anywhere so I'm thinking about using GFI breakers. Would they work or am I better of with GFI recepticles?

One thing to consider is which would be easier to reset when they trip.

 

[Flatmotor]

I have a new to me 50's house and the outlets are a two wire system. There are no GFI outlets anywhere so I'm thinking about using GFI breakers. Would they work or am I better of with GFI recepticles?

It would probably be better to use GFCI receptacles in case you have shared neutrals or other creative branch circuit wiring that you aren't aware of. Bill

 

[roofster]

The panel is in the basement so it would pita if a breaker triped. Its a Murray panel and has a list of breakers it takes. One is Bryant style BR. Is that the same as an Eaton BR? Menards has those. Anyways, I'll probably take flatmotor's advice since who knows how this place is wired. Thanks all.