Lost my Ground

jodywoj

I used one of these to convert a traditional outlet to a surface mount so I can run additional outlets in my garage. I'm in Chicago, so everthing is in EMT. When I added this extension box, my outlet was no longer grounded. I added a green ground wire to the ground screw in the back of the box and connected it to the outlet and now my tester reads OK. My question is whether or not this outer box is now grounded or just the outlet. Also, can this ground wire which is screwed to the back of the box, be used as a ground for another circuit running through the same box or does each circuit need a seperate ground wire from the panel? The new circuit is going to be for new outdoor outlets. I figured I should add a ground wire and not rely on the conduit outside.

joed

The receptacle should have a ground wire to the ground screw. How was it supposed to be grounded without the wire? I don't see where a receptacle could be fastened to that box to pick up a ground. The receptacle would need to be a self grounding for that work anyway.

__________________
Do not PM with questions that can be asked in a forum. I will not respond.

jodywoj

In Chicago, there normally is no ground wire. The emt connected to the panel carries the ground to the box which carries the ground to the outlet. This outer extension box connects to the mudring of the metal box in the wall via the two screws normally used to attach the outlet.

nap

that is only acceptable if you use self grounding receps and follow the directions for installing them so they will be self grounding.

So, have you installed a mud ring on the front of that extension for the recep to fit onto? Are you using a raised cover?

the screws connecting everything together are rated as grounds but obviously, if you removed the recep and did not have a tail attached that was attached to the box, you would lose your ground until it was remounted.


and that is just one more reason why I still pull an EGC when using metal conduit.

One thing that came to mind is the extension ring must mount snugly to the plaster ring and the plaster ring needs to be clean. The screws are acceptable as a ground but only if the two pieces are joined tightly so the screw threads will be snug in the mating threads.

jodywoj

I was using a raised cover. I checked for ground once everything was put back together. That is when I discovered that the ground was lost. I can still pull a ground wire from the panel. The conduit is 3/4 so there is plenty of room. Would I need to pull two grounds, one for this circuit and one for the additional circuit?

Thanks.

jbfan

One ground wire is all that is required.
Wire nut them together and make sure you run a wire to the box as well as the receptacle.

__________________
Yes I am a Pirate, 200 years too late. "Jimmy Buffett"

jodywoj

Got. Thanks. But what does "fun" a wire to the box mean?

nap

you do not have to pull any wire if you don't want. Your recep should be grounded by virtue of the connections through the boxes unless you are using an isolated ground receptacle (I think a green dot on the face indicates iso ground devices).

just run a pigtail to the box in the wall from the recep and make sure everything is tight to each other.

an no, you would not pull 2 ground wires, just one and the size would be based on the largest circuit in the conduit.

jbfan

fun=run!
Fat finger problems.

__________________
Yes I am a Pirate, 200 years too late. "Jimmy Buffett"

jodywoj

Thanks again for all the help. All this is for xmas lighting next year. Too many extension cords this year. My wife just loves xmas lights.

Scuba_Dave

If you have less then 15 dedicated Christmas circuits then something is wrong