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Electrical Help - ASAP!!!

Posted by raider1966cv (My Page) on
Sun, Aug 18, 13 at 23:35

Hi Hope you guys can help me.

Had a breaker trip recently. Upon investigating the cause, I've isolated the problem to the electrical line that feeds my shed. What I discovered is that the ground wire is "hot".

Here is how the line to the shed is set up:

Power to the shed is tapped at a GFIC outlet at the exterior of my patio. The line goes down the GFIC Box through conduit under my patio slab.

Note: when I had the patio slab poured I told my contractor about the plans for a future shed which I wanted to have power run to it. I told him the line would be tapped via the GFIC outlet. He then went ahead and put in grey conduit and ran 14/2 NM through the conduit. The conduit was laid on top of the area where the patio was going to be poured. All worked well for the past 6 years until now.

Please note that I think the contractor screwed up by not trenching and burying the conduit "underneath" the slab, but simply laid the conduit in the area where concrete would be poured and thus enveloping and imbedding the conduit within the slab. What I think has happened over time is that the patio has moved at the control joins and shifed and "snapped" the conduit and thus damanged the wiring. At least this is my thoughts.

My conclusion is that I have to "pull" the 14/2 NM and fish in new wiring or simply abandon and start over. Any ideas suggestions?


Follow-Up Postings:

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RE: Electrical Help - ASAP!!!

Conduit doesn't have to be buried too deep if it is under concrete. Plan old nm is not rated for buried conduit. Use uf cable or single thwn wires in conduit to replace old nm if possible.


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RE: Electrical Help - ASAP!!!

It sounds like an illegal installation for a couple of reasons. First, as Auger01 says, underground is *always* a wet area and NM is not approved for such. Cable is for most cases NOT permitted in conduit (the suggestion for UF here is BOGUS). THWN or another approved wet rated conductor needs to be used.

Conduit that's approved for such, can be embedded in concrete slabs, but just putting it on the bottom and throwing concrete over it is not proper either.

But most likely the issue is that the conduit got water in it (you can't really stop it) and the NM has become waterlogged. Either that, or you've got a real ground fault out in the shed (but I presume you've divided and conquered that aspect of things).

You can try pulling back the NM and putting in proper conductors, but I can tell you that it may be a daunting challenge after a passage of time.


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