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We're rural and the house plumbing is from a lake-draw system with a submersible pump.

We just noticed that the power wire out to the pump had its sheath damaged in the spring time by either the ice going out, or driftwood in a storm, or something. The inner wires are not damaged. That spot will be under water in the spring.

Underwater wire was ripped open through abrasion

The question is: how to patch it?

The submersible pump is far enough out that pulling it up and re-wiring it is a huge job (not to mention digging up the lawn).

We're hoping for a solution involving heat shrink, electrical tape, maybe clamping some PVC around the outside, etc.

Eilon
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Mike Ounsworth
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5 Answers5

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Look for an underwater cable splice kit (standard listed product) and just use the outer encapsulating part of the kit, if the inner conductors are not damaged. The splice kit fill (an insulating material) will take care of any local insulation damage inside the splice kit shell if you ensure that wires are separated where damaged before filling. Usually a mold that clamps around the cable jacket and gets filled with an epoxy or epoxy-like (perhaps more rubbery than stiff) substance to seal the deal after the splicing is done.

You may want to carefully cut away a bit more of the jacket and clean all that sand out of there first. You may also opt to cut out a few feet of damage and actually splice, or more than a few feet & splice twice to insert a new section of cable.

When you get to redoing it right, install conduit (no more digging up the lawn after that, and more protection from damage.)

Ecnerwal
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I doubt that can be easily and safely repaired. Water and contaminants have infiltrated the outer protective cover, which will wick quite a distance into the outer cover. In addition, that black line does look like its own insulation has been compromised.

Without knowing the specifics of what you're dealing with, I'm thinking that you'll need to, at a minimum, pull out any line that's been underwater or contaminated all the way to the pump. Then put a suitable weatherproof junction box (above ground, most likely) near the waterline where you can connect the new pump's line to what's buried coming from your house.

Unfortunately, this means you'd need to pull out the water line as well, but I'm not seeing any other safe option for you.

Milwrdfan
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I'm going to add something to Milwrdfan's answer, in that I agree the cable should be replaced.

That's not UF cable, and looks curiously like NM cable, in that it seems to have a simple jacket (UF isolates all three wires in a poured nylon sheath). You've lost a good inch out of it at least. You've also demonstrated why not even UF cable is suitable for this application

Underground rating presumes physical protection by the surrounding earth.

It also sounds like this cable is fully exposed part of the year by a receding water line. You're lucky it didn't take more damage or you might be talking hospital bills. A splice is a mere band-aid for the problem (almost literally) and you're rolling the dice just fixing this one spot.

A while ago we had an excellent question about how you run wires underwater and I'll quote ThreePhaseEel

We will be using LFNC by the spool for a long run, or at least the longest coils you can get, here, to minimize the number of couplings to act as potential leak points.

And myself

What looks like a good pick here would be the newer XHHW-2 wire.

You could also go stainless steel conduit as well, but it's probably far more expensive and difficult to work with. In either case, you would avoid needing to splice cables underwater, and you would avoid any further damage.

Machavity
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I would use self-sealing rubber tape. The ground wire has been wet, so may begin to corrode. If possible, a hairdryer or heatgun could disperse water before you seal it back. Whatever you do should buy you some time.

https://www.amazon.com/3M-Temflex-Rubber-Splicing-Tape/dp/B005298APQ

John Johnson
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You can wrap it with electrical tape, and then apply pvc cement to melt/rebond the tape into a shell. https://99mpg.com/mikestips/blacktape/

simon
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