I have 4 350 mcm wires about 250 feet underground from switchgear to vault. I have tried everything to pull these wires out, they don't move an inch. Anybody have a method I can try? The 4 inch conduit needs to be reused for the school facility upgrade.Plus I have salvage rights for the copper.

[This message has been edited by skipr (edited 09-02-2006).]

"The 4 inch conduit needs to be reused"

May be time to find a new engineer for this job, sounds like he thinks he can save some bucks by trying to resuse the conduit, we usually never bid a job like that, with the intention that the conduit can be reused, usually what you find even if you can pull the feeders, is damaged conduit, not much good for pulling new feeders, shorter runs smaller feeders, you may have some luck, when you dig up the existing run, you will most likely find, either crimped conduit or a shift in the run near a coulping, or bend.

Just wondering, what did the old feeders meg out at?


[This message has been edited by LK (edited 09-02-2006).]

You're probably out of luck.... and have some digging in your future!

It is fairly common for ponduit to be damaged during backfill, compaction, etc. This is particularily true when the pipe was installed by non-electricians, not buried deep enough, clean fill was not used, and the pavemant is subject to heavy traffic.

First I would sugest hooking up an air compressor. You might blow the blockage free. You certainly ought to be able to hear the air exit the pipe.

If you haven't done it already, trace out the line, marking the pavement as you go along. It is possible that there is a buried splice box. (See "A well buried box" in the picture forum).

https://www.electrical-contractor.net/ubb/Forum5/HTML/001235.html

Ian A.

You could try some of this . There is also a cable removal puller that puts a tension on the cable and then vibrates it to break it loose. I don't know who makes it. I remember reading about it a few years ago.
Don

I've also had some luck hooking a fire hose to one end of the conduit and letting it flush out the silt. This will only work if you have a place to let the water and silt run out on one end. When I did it, we flushed from inside of the building out to a manhole and then pumped out the manhole.
Don

Two words

Back hoe

If we installed the conduits like the utility does, there would be no problem, OVERSIZED, but usually when a contractor does the job, what is the smallest i can get away with, switchgear to vault, is usually oversized, and can be pulled.

[This message has been edited by LK (edited 09-02-2006).]

A 4" conduit with 350 mcm in it should come out.Get a choker and some muscle.

Not to be cliche, but,

"Dynamite! TNT! Things that go boom! PBX! (Plastic Bonded Explosive, thanks Alan B! ) All that fun stuff that's illegal for good reason but we have around anyways!

Ian A.

The school was built in 1963, part the conduit run goes under the building, and all of it goes under concrete foundation. Being a California K12 school they are trying to go cheap. I am not the contractor doing the new modernization. I'm the one who has to go from school to school and fix what the contractors have screwed up. I have tried the 2 ton chain pull come-a-long, I have forced water and soap mixture down the condiut. All the (six) other conduits cleared easy.Looks like im going to tell them to go overhead.

How bout a Jeep?

Been a few liquifaction quakes the 60's - maybe the building settled on it?

Give a tugger a shot one conductor at a time yet? Sometimes it works if you can get one to go, you can get the rest out.

I once had to remove 4-750MCM Al that had burned a termination and welded themselves to the inside of a PVC oonduit. The run was about 375', and 20'or so was welded.
We had 2 service trucks and a Ford tractor hooked up, and couldn't break it loose.

A young guy came by leading an elephant. He saw our dilemna and offered to help. "She loves to pull, and will work for peanuts".
She showed almost no strain whatsoever as she just walked away with the feeder in tow.

In the absence of an elephant, you might try the truck and a chain.

Use a good sized digger on heavy tracks.

If no luck you may have to dig the trench out.
It is very likely that the conduit is broken somewhere and filled up with debris hence the cables are stuck.

or ?

a hidden junction or repair was done in the past in open soil and backfilled which makes it almost impossible to get the cable out.

Please let us know what the outcome is.

Thanks

I've used Line Trucks, Trac Hoes, Wreckers, and Cranes in pulling out old feeders.

Roger

I am with Roger and RODALCO I would not give up until I actually broke the conductors.

I would cut each end of the raceway back as close to where it goes underground (without cutting the conductors) than I would prefer a large (5 ton) at least chain fall to start the pulling.

But heavy equipment if available is always helpful.

The last all terrain folk lift I rented had a draw bar rating of just under 20,000 Lbs.

If you want to know if this has happened, do what Don said, and go grab a firehose. If the conduit's broken, you'll see a geyser. If there's a box underground, you'll probably see water bubbling up as it exits the box and creeps up.

Ian A.

[This message has been edited by Theelectrikid (edited 09-03-2006).]

put a sign out front, the copper thieves will have it out before sunrise!!!

LOL

If you blow or vacuum the pipe put a bottle of yellow 66 in there after flushing and blow that through. If you ever get the wire moving that will help it go.

May I offer a suggestion that nobody has mentioned?

If you break loose the stuck wires, stop and tie a pull-rope on at the other end before you remove them.

I'd feel like an ass for forgetting that on a 250' run!

I took a combination of your advice. I flushed palmolive liquid soap with a fire hose down pipe, put my 2 ton chain puller, put alot of tension on it, and beat it with a sledge hammer to vibrate it loose. One conductor at a time, they get easier as each one coomes out. Thanks Oh BTW, Were you serious about the elephant? And yes Larry I remembered the pull rope.

[This message has been edited by skipr (edited 09-04-2006).]

Skpr, I would now try to swab out that conduit before putting new conductors back into it. Palmolive soap is probably not so good for the wire insulation.

You mean run a wadded up rag or something? Probally not a bad idea. Isn't that soap biodegradable?

But it WILL leave your hands fabulously soft and smooth!!

("You're soaking in it." "Dishwashing liquid?!?" "Relax, it's Palmolive.")

Anyone else remember those ads?

But seriously, there is a risk of degrading the conductor's insulation by using anything other than approved pulling lubes.

And swabbing out the conduits will tell you if thery're going to be safe for the new conductors.

Simlpy tie (very securely!!) a rag to the end of a pulling rope and pull 'er on through. Or you can use a mouse of the correct size.

You should pull a mandrel through the conduit to prove it is ok to install new conductors. As others have suggested, there may be underground damage. If you do us a madrel, make sure you use a pull rope on each end.
Don

[This message has been edited by resqcapt19 (edited 09-05-2006).]

I'll let Electure confirm, but I'm pretty sure it was a true story about the elephant.

Were you in India Scott?

The best free advice you can get.

If the job specs are good they will require a witnessed mandrel test anyway.

However if it was up to me I would try a full size mandrel, if that did not pass I would try a mandrel that is the required raceway size of the conductors I planed to install.

I would also have looked at the conductors I pulled out to see if there was a something obvious holding them up. If there was damage it would also give an indication of where the damage is located.

Lets keep in mind it was the customer that wanted the conduit reused, it's not an EC 'cheat'.

I don't know if the soap will damage the insulation or not, but it will set up like adhesive when it dries out. I have a friend who is also an EC who used to always use dish soap for pull lube. When trying to remove conductors from a conduit to reuse the pipe after a couple of years he found out just how well dried soap works for an adhesive. 10 #12 stranded THHN in a 3/4" EMT run of 250' would not break free.

Put some heat and time on some approved lubes and they too glue up good.

Dishwashing soap is not pulling lube.
I worked on a hospital where they used dishwashing soap to pull all the wires. Fifteen years later, the TW insulation could be rubbed off the wires with little effort. Same with gear lube, axle grease, etc. Use what's right and approved for the use. Hard to beat Yellow 77. You can go back 10 years and it'll still be relatively slick.

I hear that Vaseline wreaks havoc with latex condoms, too.

Try a little baby powder!

I have never seen Yellow 77 set up like glue and I have pulled out some runs that were 18 years old. My current favorite is Aquagel.

I have never used anything but yellow 77 to pull IN wire. This was a different situation.I was pulling out wire that has been underground since 1963. After the first one broke free the other two were easy.BTW the RHW insulation was a material called permaprene made by Hatfield. Anyone ever heard of that?

Someone would have to be holding a gun to my head before I used that yellow junk again, I always see it set up like glue.

We use 'Dyna Blue' which is water based and will evaporate almost entirely.

Clean up is also much easer.

I shall now let you all know the secret lube used by us steam-age boring old wrinkled fahrts, creaking about on our zimmer frames. This is not, I assure you, a joke, I have used the stuff for decades on old machines to ease parts together or apart. You can buy in at any 'Walmart' and it's cheap:

Bananas!!!!!!

Banana pulp, the finest and slippery-est lube known to man.
Biodegradable,
Non-toxic,
Water-soluble,
Will not age to glue.
Won't cause rust, won't affect plastic, copper, rubber, steel or aluminum.
Slippery as a Wall Street lawyer.
Can be also fed safely to Elephants.
Low calories, so any excess can be fed to the crew as a bonus.
And - it smells nice!

Alan

I would use butter and have some English muffins going so when you're done the crew can have a nice coffe break.

Alan, I remember a friend in high school whose dad told him to shove a banana in an old datsun transmission that was making all kinds of noise and was shifting hard. He said he did and to this day swears it made it act like a new transmission. I remember he did drive it for a year or two after he said he had done it.

Roger

Alan, there is one bad thing about bannanas, potasium. Too much of it will leave you.... well rather limp.

How ironic.