Eletrical outlet questions

[SkunkedAgain]

I had an bad outlet in our bedroom so I thought that I'd be smart and replace everything. I never tested it prior to starting my work, in order to see if it was grounded. I pulled everything out including the old metal box. It was nailed to the wood stud. There were four cloth wires running to the old outlet. I knocked out the tabs in a new plastic box. I ran the cloth wires into the new box and hooked them up to the new outlet in the same manner. I put everything together and it works, but is not grounded. I thought that the old one was grounded.

Here are my two questions:

1) Could the old outlet have been grounded via the metal conduit that brings the cloth wires to the outlet?

2) I wrapped the deteriorating cloth wires in electrical tape so they wouldn't touch eachother. Is there a relatively easy way to splice the wires and put in something safer without cutting a giant hole in my bedroom wall?

[Jim Almquist]

1) Could the old outlet have been grounded via the metal conduit that brings the cloth wires to the outlet?

Yes if the conduit went all the way back to the panel but the fact that you only have 4 wires tells me that you more then likely have 2 white and 2 black and your wires are coming from a outlet and going to another outlet. Because of how old your wire is there might not be any color. I am running into the same thing in my house and I am contemplating running a ground from the basement up to each jack but it will be a pain but they are the only outlets in the house that are not grounded. I was going to pull the basebords off and drill a hole down and put a hole in the sheet rock and fish the ground cable into the outlet. Lots of work but it would be nice if all my outlets were grounded and up to code.

[BobT]

I had an bad outlet in our bedroom so I thought that I'd be smart and replace everything.

[PerchPounder]

If I'm understanding you correctly it sounds like you have a "knob and tube" system which is a very old way of doing things. If that's the case you likely never had a ground at any of your outlets. The conduit you seen was likely just a tube that the wire is pulled through and only runs into the attic where it stops.

Long story short and knowing nothing about your house I would say that there isn't a simple way to just change the wire from the old cloth insulation to modern plastics. it would likely require extensive labor and time to repull the circuits all the way back to your panel depending on how many you decided to do.

[Surface Tension]

First off I'm not an electrican.

I've run across many a knob and tube on gutting jobs.

This isn't a knob and tube for the reason of the conduit.

What you have is called conduit armored cable. Both knob and tube and conduit armored cable were used around the same time.

K&T cost a less and was easier to run then conduit armored cable. Of coarse one cost saving was no conduit with K&T.

Here is an other savings, K&T hot and neutral are spread apart on a run and for that reason they cooled with high loads as opposed to conduit armored cable with conductors close and enclosed to each other. Because of the self cooling more receptacles could be run on a K&T circuit which was another cost savings.

So how does a frame to finish carpenter know that.

Well, you can't blow cellulose insulation into a building with K&T because the insulation blown around the K&T will over heat the wires that were intended to have air circulation around them to cool.

To answer your question, no the conduit armored cable is not grounded.

[JohnMickish]

It's not knob and tube, it was done in greenfield (flex). I am guessing the house was built somewhere between 1930 and 1960's. This was common practice before the invention of Romex.

Like Bob said, put a metal box back on it and make sure the flex is attached to the box with the proper connectors to get the best ground you can. There is a reason things are done in a different manner in todays houses.

You can always go back and try to pull in a ground wire, that would probably be the best and safest.

[Chad711]

Isn't the Neutral wire your ground anyways, just another path (wire). Both ground and Neutral both go to the same spot on a panel, right? I'm also not an electrician but my work field occasionally requires it. Or am I completely missing something here lol...

[waskawood]

A neutral wire and a ground wire are not SUPPOSE to be the same thing. A neutral wire is the return path back to it's source. The ground wire is to provide safety such as placing an appliance at earth (ground) potential. All that being said the neutral wire is suppose to be at earth potential. (grounded) A neutral is a current carrying conductor and if it is severed, can be dangerous as the current then trys to find other paths to complete it's circuit back to it's source. If that path is through your body death can result. Remember, 120 volts kills more people than any other voltage. It is to be respected. A ground wire shouldn't have current flow through it if the circuit is intact and designed correctly.

[JohnMickish]

A neutral wire and a ground wire are not SUPPOSE to be the same thing. A neutral wire is the return path back to it's source. The ground wire is to provide safety such as placing an appliance at earth (ground) potential. All that being said the neutral wire is suppose to be at earth potential. (grounded) A neutral is a current carrying conductor and if it is severed, can be dangerous as the current then trys to find other paths to complete it's circuit back to it's source. If that path is through your body death can result. Remember, 120 volts kills more people than any other voltage. It is to be respected. A ground wire shouldn't have current flow through it if the circuit is intact and designed correctly.

Very well said. The neutral may be groundED, but it is not the groundING wire. There is a difference.

[BobT]

Absolutely! In fact, that's how a GFCI works. It monitors the current flowing on the ungrounded (hot) and the groundED (neutral) conductors. They should ALWAYS match. If there's a difference the GFCI detects it as a ground fault and opens the circuit.

The groundING conductor should carry current only in the event of a ground fault. It must be capable of carrying all the short-circuit current and force the OCPD to open.

Incidentally, the terms "hot" and "neutral" are misnomers. The more correct terms are "ungrounded" and "grounded" conductors because they are carrying all the circuit current.

[SkunkedAgain]

Thanks everyone. I think that the best solution is to bring someone in to do the job right. I appreciate all of the replies.

[BobT]

Smart decision.

[SkunkedAgain]

I think that the smarter decision was to unplug the electric blanket!

[CatchPhotoFilet]

Id say just put a new metal box back in the previous hole and put in a Green 8\32 grounding screw in one of the back holes in the box and ground your outlet to the grounding screw.

[JohnMickish]

Ground screws are 10-32.

[BobT]

Id say just put a new metal box back in the previous hole and put in a Green 8\32 grounding screw in one of the back holes in the box and ground your outlet to the grounding screw.

That doesn't solve anything if the box itself is not bonded to earth. In fact, to do that and then install a 3-prong receptacle might not only be illegal but might be downright dangerous because it provides a false sense of security.

[SkunkedAgain]

I'll try at least putting a metal box back in there to see if the metal conduit was in fact supplying the ground.