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I just removed a deck in my backyard.

Under it was some of the electrical wire that runs from my home to my garage (pictures are below).

Can someone recommend the best steps to burying this underground?

What you see in the photos is the only portion that is exposed.

Thank you!

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  • What does the wire/conduit go to? All the way to the house?, previously to an outlet on the deck? Where does it start from? What size and how many wires are running through it? – Limo DRIVER Jul 31 '18 at 18:15
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    If I were going to the trouble of digging a trench to bury the wire, which you'll have to do, I'd just install PVC conduit and run the wire through the conduit. Either way involves digging. If buried, it should be (if memory serves) at least 18 inches below the surface. – BillDOe Jul 31 '18 at 19:32
  • @BillDOe, looks to me like it's already in full conduit. – isherwood Jul 31 '18 at 19:39
  • @isherwood, agreed. But the OP was talking about putting it underground. – BillDOe Jul 31 '18 at 19:42
  • Are you in Canada by chance? – ThreePhaseEel Jul 31 '18 at 22:34
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You may not even need to alter the existing conduit setup. I'd trench under the existing pipe and alongside the vertical run. I'd then simply lay the vertical run over on its side, allowing a substantial length of pipe to twist in each direction. Get it down 6" or more and stake it down, if necessary, before re-burying it.

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    For rigid pipe or IMC 6" would be ok. If 120v and gfci protected 12" would be ok but if 240 it will need 18" per table 300.5 in the NEC. The 6" depths are under concrete or rigid / IMC not NM conduit. – Ed Beal Jul 31 '18 at 20:04
  • @isherwood -- you can't bury the run as-is due to the LB (what you describe would violate NEC 314.29) – ThreePhaseEel Jul 31 '18 at 22:24
  • True, but it's what I would do. This is an existing run that's unlikely to change. I wouldn't anticipate ever pulling new cable. I'm a renegade that way. – isherwood Aug 1 '18 at 13:39
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You will need to redo this part of the run

It appears that part of the run does not meet minimum burial specifications (aka the 18" cover depth required for PVC conduit); also, that LB and several of the bends will need to go in order to avoid violating the 360° rule between pull points and keep the LB from becoming inaccessible.

As a result, you will need to redo this section of the run completely. The first step will be to turn off the breaker in the house and disconnect the wires at the house end, then go to the garage and pull the wires out of the conduit completely from that end. Then, you will have to excavate along the conduit from where it enters the ground down to where it meets the 18" cover depth (and a couple extra inches), as well as excavate out a 19-20" deep pit around the wide-sweep elbow below the LB, and connect the two excavations with a 19-20" deep trench in an L shape overall (draw straight lines out from where the conduits go, and then trench along those lines, yielding two trenches that cross at roughly a 90 degree angle).

Once you've done the trenching, you can then install new conduit as straight runs of 1/2" schedule 40 PVC fitted to the existing runs using couplers at the ends and with a wide sweep elbow used at the bend. Backfilling the trench is straightforward, and then you can pull the wires back through, probably with the aid of a pulling string sucked through the conduit with a shop-vac and a plastic grocery bag tied to the string. Once the wires are back in (you should have sufficient length in the existing wires to reconnect them given how much length was taken out by removing the needless depth variations), you can then reconnect them at the house end, turn the breaker on, and call the job done.

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ideally that whole wire needs to be replaced with a armored cable, with enough slack to bury it in a ground a couple of feet.

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  • North American type AC cables are not rated for direct burial service. There are type MC (Teck90 for Canadians) cables that are, but it doesn't make sense to rip out and replace a conduit job with cable wholesale given the advantages of conduit as a wiring method. – ThreePhaseEel Jul 31 '18 at 23:00

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