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I found some PVC electrical conduit which is about 2 inches deep:

conduit exposed in the dirt by the back patio

The conduit could contain 240v or 120v AC, and would have to be traced back to the source to be sure. Also in the picture is a coiled up copper wire which I suspect was meant as a tracer line.

Would it be safe (and per code) to fabricate a steel 'U" channel and "armor" it instead ripping it out and installing a deeper conduit?

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    Your picture didn't post: also, would putting concrete over the conduit cause any issues? Commented Aug 23, 2021 at 0:07
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    Please edit your post then simply drag the pics into the edit box. The site will upload & host them for you. If you're still having issues, upload them somewhere like imgur and post a link in the comments - someone will embed them for you.
    – FreeMan
    Commented Aug 23, 2021 at 18:29
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    Does it have AC power in it, or is it just telephone or internet lines? Commented Aug 24, 2021 at 0:17
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    A browse through your breaker panel should give you a clue as to what's in that conduit. There should be something like "outdoor lights" or "backyard outlets" or "shed" or something like that. If not, use a non-contact voltage detector against the conduit to ensure you can pick up power now, then have someone turn off breakers one by one until your NCV isn't detecting. Then you'll know which breaker it is. That will tell you whether you've got 120v or 240v running through there. It doesn't matter which it is, though, it still needs better protection.
    – FreeMan
    Commented Aug 25, 2021 at 12:27
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    I was pretty sure the conduit was housing a 240 line that runs under a slab and exits to feed an AC unit. I used a tone generator at the exit point and probed the original section of conduit to verify the circuit is the same. Commented Aug 27, 2021 at 3:53

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To encase the cabling in a PVC conduit ("non-metallic"), the top of the conduit must be 18in below grade.

To encase the cabling in a rigid metallic conduit, the top of the conduit must be 6in below grade.

There is no exception for conduit that is covered by a metal cap of some sort.

However, there is no (!) depth requirement for PVC conduit in a concrete slab. The recommendation is to prevent a trip hazard (usually around entry/exit points) and to keep conduits deep enough to be below the depth of a relief cut saw ("relief cuts" prevent uncontrolled slab cracking). But I don't think you'll be cutting.

There may be minimum cover requirements arising from the requirements for the strength and durability of the slab, but not for electrical reasons. For a backyard pad covered by pavement stone there may be very little required of the concrete.

So, you could pour a small slab around the conduit and sufficiently protect it that way. I believe non structural "slabs" and "pads" are not technically defined for size and depth, but tread carefully if you wish to walk the edges of the code.

I am not an electrician, and this is what I gather from reading and my experience with concrete scanning. This is a good question, and I hope that my answer will attract some more attention and discussion.

You could also ask you local city ("Authority Having Jurisdiction" - AHJ) and ask generally about requirements for PVC conductors in a concrete pad or slab. Be specific, since "in" a pad is not the same as "under" a pad. If "under" pad, the conduit must be 4in under a minimum 4in thick pad.

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  • Thanks for the info. I am thinking of extending the pavers to cover the conduit. There is a problem on the other side of the patiio though. That is the suspected path of the conduit is a section covered by river rock. Actually, the 6 inches below surface is not that bad. Commented Aug 27, 2021 at 4:03
  • @johnchristensen how about just digging a 4in diameter ditch around the conduit and filling it with concrete. You could even mix it in the ditch with a hand shovel, if you don't want the mess or obligatory weightlifting.
    – P2000
    Commented Aug 27, 2021 at 5:50

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