Underground RMC Repair

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Cow said:
I can't help but think, eventually you have to stand back and ask how far are you willing to go just to scab it back together?

At some point, it just makes sense to pull the wire out and redo it properly.
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Supposedly the conductors won't pull out, but that may be a sign that it should have something different done anyway.
 
tkb said:
If the conductors can’t be removed, I would question the integrity of the rest of the conduit and the conductors.
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This gets my vote as well. How many other couplings in the run are disintegrated? Are the conductors soon to follow?

If the conductors were removed, a 3 piece coupling could be used, if the run is encased in concrete. You just need enough of the run exposed to bend the pipes apart enough, about one pipe diameter, to install the coupling, then bend back together to secure the union. Not too difficult with a couple hickey benders. Encase in the pour, and the result is an approved, listed for grounding repair.

MTW

http://www.cooperindustries.com/content/dam/public/crousehinds/commercial-products/catalog-pdfs/conduit-couplings.pdf

cch_cp_rigidconduitcoupling_threepiece_220.jpg
 
MTW said:
This gets my vote as well. How many other couplings in the run are disintegrated? Are the conductors soon to follow?

If the conductors were removed, a 3 piece coupling could be used, if the run is encased in concrete. You just need enough of the run exposed to bend the pipes apart enough, about one pipe diameter, to install the coupling, then bend back together to secure the union. Not too difficult with a couple hickey benders. Encase in the pour, and the result is an approved, listed for grounding repair.

MTW

http://www.cooperindustries.com/content/dam/public/crousehinds/commercial-products/catalog-pdfs/conduit-couplings.pdf

cch_cp_rigidconduitcoupling_threepiece_220.jpg
Click to expand...

So, exactly how do you slip this fitting on without cutting the wires??? Can't pull them out, remember?
 
Cant pull them out? I have reworked plenty of old corroded, debris and dirt filled conduits in gas stations and plants underground. Getting out the old settled in wiring and debris is usually harder than repairing or rerouting the pipe. But if replacing the run involves digging up a gas station tank field and parking lot, you work harder at getting them out and flushing out the pipe, before you attempt a replacement pull.

We would flood them with water, and use a compressor to blow them clear, sometimes multiple times to clean them enough for reuse. Its hard work, but usually can be done with time and determination.

If I remember correctly, the OP said that they already replaced one run with an above ground replacement, so maybe that would be easier and less time consuming.

If the existing pipe run was being used as the equipment ground, and has no grounding conductor installed in it, I wouldn't be reusing it, without a repair and re-pull, but that's me.

MTW
 
FWIW Polywater makes a specific formulation for pouring into the raceway to loosen up the wires. It works best if the hang up is old fashioned pulling lubricant that has oxidized and hardened, but it may help with dirt and corrosion too.
Blow that in, maybe after a water flush and air clearing, and let it sit for a couple of days.
 
RICK NAPIER said:
The contractor says he can't remove the conductors.
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depending on the soil, and how aggressive it is, the inside of the conduit could be
filled full with rust.

the pool feed on my pool was 1/2" GRC. when i replaced it, it had been in the ground
here for about 40 years. cut it in sections, and it looked like MI cable, with the filler
being rust.

we have a local requirement to use stainless steel ground rods for that reason.
huntington beach was a huge oil town, and the soil will corrode anything.
 
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