Conductors stuck in underground conduit

[conmgt]

I have about 20' of 2" rigid under an interior slab that has 4 #4 THHN conductors stuck in it. It appears to be that rust has a hold on them. Possibly wire lube from years ago has rusted the rigid and the conductors together. One end of the conduit points vertically but in a tight location. And the other comes out of a wall horizontally.

I wrapped a strap around the conductors and tied the other end to a 10' unistrut. I used a block of wood as a fulcrum and it didn't budge an inch.
Has anyone succeeded in getting out of a similar bind? Any suggestions on what could be poured into the conduit to free the conductors up?

 

[petersonra]

maybe you just did not have enough leverage. perhaps a hydraulic jack instead of your back. Maybe leave it over night as tight as you can get it?

 

[don_resqcapt19]

You could try Polywater's Cablfree.

 

[JDBrown]

You could try Polywater's Cablfree.

I was thinking, "Well, when we were kids and we found a pocket knife that had been left out and rusted closed, we soaked it in diesel overnight."
But filling the conduit full of diesel probably wouldn't be such a good idea. Don's suggestion seems like a much safer way to go.

 

[Dennis Alwon]

I remember having this issue in a stone crushing plant in NY state. We got one of their machines to pull the wires out. There were splices in the middle of the conduit. Unreal....

 

[dhalleron]

I remember having this issue in a stone crushing plant in NY state. We got one of their machines to pull the wires out. There were splices in the middle of the conduit. Unreal....

Around 1988 I helped on a project. The lead electrician was pulling #10 THWN about 1000' (maybe it's been awhile) from a panel to a sign out by the road of a grocery store. For whatever reason the wire ran out on the spool before it got to the sign. Maybe that's because we were using 500' spools.

The next spool was a little short reaching. He made about 3 splices on each conductor. Crips, rubber tape, black tape. I wonder how that stood up over time?

 

[petersonra]

Around 1988 I helped on a project. The lead electrician was pulling #10 THWN about 1000' (maybe it's been awhile) from a panel to a sign out by the road of a grocery store. For whatever reason the wire ran out on the spool before it got to the sign. Maybe that's because we were using 500' spools.

The next spool was a little short reaching. He made about 3 splices on each conductor. Crips, rubber tape, black tape. I wonder how that stood up over time?

my guess is that it held up fine.

 

[mjf]

Maybe you can get a single conductor to move and maybe that would loosen all of them?

 

[texie]

You could try Polywater's Cablfree.

I've used this in the past for situations like this. For bad situations we pour it in the pipe and the connect a large air compressor to one end to disperse it all the way to the other end. Let soak 24 hours or so and connect a puller. If they still don't budge it sometimes helps to leave it under tension overnight. If some of the pipe is exposed, hammer on it with tension on the conductors. This takes patience but usually can be done, as the trick is not to pull so hard that you break the conductors.
We've also had the case, as I'm sure others can attest to, where after trying to pull out conductors, somebody says, oops, we just found a J box that we didn't know about.

 

[cowboyjwc]

Depending on how long it's been there, there may not be any RMC still in the ground. So even if you got it out, you would never get anything back in.

 

[Lectricbota]

I've used this in the past for situations like this. For bad situations we pour it in the pipe and the connect a large air compressor to one end to disperse it all the way to the other end. Let soak 24 hours or so and connect a puller. If they still don't budge it sometimes helps to leave it under tension overnight. If some of the pipe is exposed, hammer on it with tension on the conductors. This takes patience but usually can be done, as the trick is not to pull so hard that you break the conductors.
We've also had the case, as I'm sure others can attest to, where after trying to pull out conductors, somebody says, oops, we just found a J box that we didn't know about.

Man, I just hate that

 

[ptonsparky]

We left existing undergound 500 mcm cu in conduits when we nstalled a new service to new padmounts. Customer responsibility to remove. They got all but the last.set before almost upending their good sized skidsteer trying to pull them out. My suggestion of "did you disconnect the other end" was met with "uuuhh.."

 

[kwired]

Around 1988 I helped on a project. The lead electrician was pulling #10 THWN about 1000' (maybe it's been awhile) from a panel to a sign out by the road of a grocery store. For whatever reason the wire ran out on the spool before it got to the sign. Maybe that's because we were using 500' spools.

The next spool was a little short reaching. He made about 3 splices on each conductor. Crips, rubber tape, black tape. I wonder how that stood up over time?

I would think the risk of pulling a splice apart on a long pull is pretty high, or worse yet pulling it to the point where it is still in contact but barely.

 

[John120/240]

I have about 20' of 2" rigid under an interior slab that has 4 #4 THHN conductors stuck in it. It appears to be that rust has a hold on them. Possibly wire lube from years ago has rusted the rigid and the conductors together. One end of the conduit points vertically but in a tight location. And the other comes out of a wall horizontally.

I wrapped a strap around the conductors and tied the other end to a 10' unistrut. I used a block of wood as a fulcrum and it didn't budge an inch.
Has anyone succeeded in getting out of a similar bind? Any suggestions on what could be poured into the conduit to free the conductors up?

A two liter bottle of Coke has been known to loosen up things. YMMV

 

[Ponchik]

I think i read in the ECM magazine or one of the threads here, you can soak the conductors in mineral oil, let it sit for 24 hours or so. Then see if that helps.

As suggested by others, having the conductors in tension and taping the conduit is a great idea.

 

[Ponchik]

I just thought about liquid plumber. Will that work??

 

[GoldDigger]

I just thought about liquid plumber. Will that work??

Other than making things incredibly dangerous for everything after that, it is unlikely to do anything for rust or corrosion. If the wires are being held in place by hair and grease, maybe.....

 

[EV607797]

I had a similar situation, a 2" RMC that ran about 200 feet that had two 25 pair telephone cables in it. None of them would budge, in fact one of them broke on the first hard pull. Since we were replacing these cables, we really didn't care if they got damaged or broken, so we contacted a drain cleaning company to run their power snake through without a cutting head. He only had to spin it back and forth and moved it forward about two feet at a time. By the time he got the snake all the way through, the movement within the pipe had loosened the rust/dirt/whatever to the point where the cables pulled right out. We swabbed out the RMC as best we could, pulled in a 5/8 rope and the new 100 pair cable went right in without a hitch.

$200.00 well spent, especially since the customer was paying for it in lieu of breaking up about 100 feet of pool decking.

 

[don_resqcapt19]

A long time ago, I remember reading about a special cable puller for removing stuck cables. It put and maintained tension on the cables to be removed and than vibrated the rope. As I recall you left it working like this for many hours and the combination of the tension and the vibration broke the cables free. I have looked for this product on the net a couple of times without success.

 

[electricguy61]

Ditto on the 2 liter of Coke. Let it sit over night. If it doesn't work, you haven't lost anything but $2.