? How to insulate/waterproof repaired underground power lines

[smiley]

I had the same situation with underground wire and got a repair kit from our utility crew (I knew the guys), that consisted of a large block of clay and tubes of epoxy. After replacing a section of wire, I formed a mold around the repairs and poured the epoxy in. That was 20 years ago and it's still working BUT, I still think about it and have a new outside breaker panel ready to replace it with overhead wire in a hurry if it fails. Perhaps the heat shrink wraps the other fellows talk about then pour epoxy around that would give more peace of mind.

 

[Midniteoyl]

I dont know guys.. Seems fairly simple. I mean, you splice and heat shrink the wires in your well and it works fine. A little self vulcanizing electrical tape with heat shrink over it will work for a very, very long time.

 

[CNC Dan]

I dont know guys.. Seems fairly simple. I mean, you splice and heat shrink the wires in your well and it works fine. A little self vulcanizing electrical tape with heat shrink over it will work for a very, very long time.

But this wire has failed in use. Going to have serious damage at the failure point, and water/dirt in the exposed wiring. And the wire jacket isn't water resistant to start with.

 

[buickanddeere]

I dont know guys.. Seems fairly simple. I mean, you splice and heat shrink the wires in your well and it works fine. A little self vulcanizing electrical tape with heat shrink over it will work for a very, very long time.

Have you forgotten that the live lines are insulated with outdoor overhead insulation and that the bare neutral is buried in direct earth contact ?

 

[6011Artist]

Years ago I saw an electrician repairing a buried line. He had a manufactored splice kit that consisted of a tube full of silicone he pushed the wires into after making his splice. It was made just to do this. Had a tube and cap made for the 2 wires to enter. Slide the wires through the cap holes, make your splice, push into tube already full of silicone, put cap on tube...you had a watertight seal. He explained that you could use a regular tube of silicone and do the same thing.

By doing this you do not splice your wire to run alongside each other and lay neat against the other. You let the wires run in the same direction so it will slide into the tube. (Think about holding your index finger and middle finger together and wrapping both fingers in tape). Now it easily slides inside a full tube of silicone and is watertight, just make sure the wires are seperated so silicone get around both wires being spliced.

I doubt the electrical inspector will approve of this but it does work.

 

[Den1952]

6011
now that you mention the cap and tube... that is how my submersible pump splices to the pump were done. they were underwater and held up for 16 years. I haven't seem those around to be found anymore.

 

[ultrarunner]

Friday had something similar on my now rental in Thruston County WA.

Power Company used special connectors for underground splice.

Half the home lost power and the tenant called the power company which found a break in the line about 42" underground on a 800' run from the pole to the transformer near the house.

One of the power company employees told my tenant to expect more because the direct burial cable is from 1977.

It's the weekend and I can't get any answers other than the break was repaired at no cost.

This is my only experience with rural underground...

35 years sounds like a very short time to have a this kind of problem... Apparantly there had been some dimming of lights and such noticed be the tenant... power company said it was most likely because the home is the last on the line.

 

[Midniteoyl]

But this wire has failed in use. Going to have serious damage at the failure point, and water/dirt in the exposed wiring. And the wire jacket isn't water resistant to start with.

So, cut back to clean and splice in..

 

[Midniteoyl]

Have you forgotten that the live lines are insulated with outdoor overhead insulation and that the bare neutral is buried in direct earth contact ?

No, I havent.. Regardless of whether it was 'proper' in the first place, the splicing is a simple straight forward job. He already stated that the other wires are still good, and that he most likely nicked this one in the first place. So, to answer the guys question: Cut back to clean wire, wrap in a layer of self vulcanizing tape, cover in heat shrink. You can add another layer of SV tape over top of that if you wish.. Simple. Effective.

 

[Midniteoyl]

Years ago I saw an electrician repairing a buried line. He had a manufactored splice kit that consisted of a tube full of silicone he pushed the wires into after making his splice. It was made just to do this. Had a tube and cap made for the 2 wires to enter. Slide the wires through the cap holes, make your splice, push into tube already full of silicone, put cap on tube...you had a watertight seal. He explained that you could use a regular tube of silicone and do the same thing.

By doing this you do not splice your wire to run alongside each other and lay neat against the other. You let the wires run in the same direction so it will slide into the tube. (Think about holding your index finger and middle finger together and wrapping both fingers in tape). Now it easily slides inside a full tube of silicone and is watertight, just make sure the wires are seperated so silicone get around both wires being spliced.

I doubt the electrical inspector will approve of this but it does work.

This was the old way of doing it. You can still find these kits for deep wells.. But, the silicone fails over time. The glue lined heat shrink seems to work better.