I think I have a dangerous grounding situation

[djjsr]

My workshop is a 100 year old brick building. The previous owner was an electrical contractor, so I've been assuming that everything electrical should be ok, but it appears I have a problem that may be serious.

It looks like all of the lighting and 120 volt wall outlets are grounded using the emt conduit as the ground. Everything seems to be working ok and I used one of those little yellow plug-in testers and everything tests ok, but it just doesn't seem right to me.

I've been told that using the conduit as the ground was common at one time.

For the professional electricians, my questions are:

1) Is this a dangerous situation that needs immediate attention?

2) If I have to run ground wires, should they be solid or stranded, bare or insulated? (everything is in metallic conduit).


Thanks

 

[kngelv]

Pics would help. Is there a sub-panel in the garage? If so, this should be an easy fix.

James

 

[KCarGuy]

I just fixed an issue at a co-workers house. Same thing...Used the Conduit as the Mechanical ground (which is OK as long as it stays connected and tight).
He had a break or something loosened up over time inside a drywalled ceiling, so his ceiling lights stopped working and he would get a shock.
So we ran a "Green" Ground wire through each pipe, from box to box and back to the panel (and Grounded it to the basement water pipe).
It works fine now, without future worries.
Use at least #10 stranded.
Cook County (Chicago) it is code to run a 3 Wire Electric system and Conduit.
Good Luck

 

[Aceman]

There are A LOT of places wired with metallic conduit used as the ground. A LOT!!

It's LEGAL!

 

[sberry]

Most of the circuits in my building are grounded via the pipe.

 

[raddksn]

don't need #10. ground conductor can be same as hot/nut. or 1size smaller

 

[djjsr]

Thanks for the quick replies guys. I guess things aren't as bad as I thought. I guess I was getting paranoid after reading some of the other threads about grounding.

I did check and tighten all of the conduit connections.

Thanks again.

 

[matt151617]

I wouldn't worry about it, it's not dangerous. If you want piece of mind then run individual ground wires (doesn't matter what kind) in the same gauge as the wires in there.

Did he run individual conductors? Because if he ran Romex there could be a ground already in there tied off at a box.

 

[PRH44]

358.60 Grounding. EMT shall be permitted as an equipment
grounding conductor.

EMT= Electrical metallic tubing or metallic conduit.
Fittings for EMT that have a UL listing qualify as a grounding conductor. A very good grounding conductor if it is installed correctly.

However it has become common practice for most engineers to specify grounding conductors in all conduit

It is always best to group the grounding conductor in the conduit with the phase and neutral conductors. however it can be run on the exterior provided it is not subject to physical damage.

 

[Gregishome]

My workshop is a 100 year old brick building. The previous owner was an electrical contractor, so I've been assuming that everything electrical should be ok, but it appears I have a problem that may be serious.

It looks like all of the lighting and 120 volt wall outlets are grounded using the emt conduit as the ground. Everything seems to be working ok and I used one of those little yellow plug-in testers and everything tests ok, but it just doesn't seem right to me.

I've been told that using the conduit as the ground was common at one time.

For the professional electricians, my questions are:

1) Is this a dangerous situation that needs immediate attention?

2) If I have to run ground wires, should they be solid or stranded, bare or insulated? (everything is in metallic conduit).


Thanks

Dang, that is one fine looking Chevy PU you have DJJSR.

 

[PRH44]

Gregishome remember the old saying the cobb;lers children have no shoes? (just kidding)

Stranded or solid wire is fine. If using stranded be sure terminals are rated for such. If not you will need to use a crimp on fork or ring terminal

 

[Norcal]

Gregishome remember the old saying the cobb;lers children have no shoes? (just kidding)

Stranded or solid wire is fine. If using stranded be sure terminals are rated for such. If not you will need to use a crimp on fork or ring terminal

Devices are not rated for crimp terminals, but most devices are rated for solid OR stranded wire.