burrs in conduit

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hockeyoligist2

Senior Member
Not sure if this is the right place to post this.
We have some almost new construction, about 2 years old, and the contractors obviously didn't deburr any of the RMC. We have had multiple shorts in the RMC, pull new wire in and it lasts a few months, shorts again. It is in concrete thru mutiple floors (industrial) from 100' to 250' runs. Does anyone make something that we could pull thru to deburr?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Re: burrs in conduit

hockeyoligist2 said:
Not sure if this is the right place to post this.
We have some almost new construction, about 2 years old, and the contractors obviously didn't deburr any of the RMC. We have had multiple shorts in the RMC, pull new wire in and it lasts a few months, shorts again. It is in concrete thru mutiple floors (industrial) from 100' to 250' runs. Does anyone make something that we could pull thru to deburr?

have you tried tougher wire? i don't think anything you can pull through a conduit is going to debur it.

maybe pull cables instead of individual wires so the overall jacket absorbs the damage instead of the individual conductors?

maybe you could sleeve the inside of the conduit with some of that blue corrugated tubing to protect the wires.
 

ceknight

Senior Member
Re: burrs in conduit

hockeyoligist2 said:
We have some almost new construction, about 2 years old, and the contractors obviously didn't deburr any of the RMC. Does anyone make something that we could pull thru to deburr?

I've never had to deal with your situation, but if you're desperate you might at least call a big plumbing company and see if they have an auger attachment that can do it.

Good luck, in any case.
 

tonyi

Senior Member
This gadget looks like it could make it down 2" for inspections.

This gadget could make it through 1/2" but has limited distance

When you say a 250' run, between floors, is that all verticle? There should be some pull boxes with support wedges in them for a run like that.
 

hockeyoligist2

Senior Member
tonyi said:
This gadget looks like it could make it down 2" for inspections.

This gadget could make it through 1/2" but has limited distance

When you say a 250' run, between floors, is that all verticle? There should be some pull boxes with support wedges in them for a run like that.
No it is out of the motor control center thru the concrete floor then maybe a 10' drop then in concrete to the machines ( 2 90's). I saved the last shorted wire and compared it to the one I pulled out this morning and it was within a few inches of where the burned spot of the last one was so i'm pretty sure it has a burr there. In the concrete! If it was only 1 I would run new conduit. but there are about 40 machines so there is no way.
 

charlie tuna

Senior Member
Location
Florida
if the problem occurred twice at the same spot -- have you considered measuring it out and chopping down and repairing the effective area. anything that you tryed to de-ber the inside of the raceway would leave enough grindings etc. to create the same problem elsewhere, or get stuck in the raceway. sounds to me that you have a bad spot at a elbow??
 

tonyi

Senior Member
Any chance there's a bunch of concrete debris in the pipe? Uncapped stubups tend to collect all sorts of junk if left unattended for any length of time.

Sometimes concrete can be loosened up with ordinary vinegar, a water flush, and dilute baking soda to neutralize any acid remaining.
 

hockeyoligist2

Senior Member
chopping into the concrete would be a no no. It is a floor dividing another floor below, so it may cause problems. I don't think there is any debri in the pipe just burrs since i pulled all wires except 2 then put a rag on one then pulled it thru it came out pretty clean except for some tares. then used the other to pull in the new wire. This one has been more of a problem than the others, but we have replaced the wire in at least 10 different ones. I know that most of the contractors "electricians" were just cheap help. (don't worry Bob I read your post) and they probably have no clue as to what deburring is.
 

tonyi

Senior Member
completely random thought:

if the pipe is big enough maybe a white teflon sleeve that would slip through the pipe, taped to the head of the pull. With enough lube it might go through, wedge against the burrs, then the tape breaks and it provide enough of a smooth collar for the rest of the pull to ride over OK.
 

hockeyoligist2

Senior Member
Thanks the next time it happens I'll try the teflon , plenty of room for it, and it can't hurt, so it might just work! :D But I'm thinking that since it doesn't short too quickly that it may be the movement of the wires when cycling on and off that it wears thru the insulation.
 

realolman

Senior Member
I think sometimes you just gotta bite the bullet.

I think if it was my place, I'd find a way to fix it right, rather than having that hanging over my head all the time.
 

H.L.

Member
Burrs in conduit

Burrs in conduit

You could try pulling a steel mandrel the pipe. Make sure that you tie a rope to each end of it. Good luck.

Hale
 

peteo

Senior Member
Location
Los Angeles
Another random thought, in addition to the teflon. Spiral wrap and split cable loom product (for cars) provide minimal cable tear protection but either will provide longer life for shaking cables (machine tools or sawmills.) If there's really room, it might be worthwhile considering sleeving in LFNC-C, which is indestructible. That, of course, means that there would be a metallic raceway with supplemental vibration protection. You'd probably want to bounce it off an inspector and/or a tech support person before going ahead. Yes I know it sounds bizarre, but the option of swabbing out means possibly injuring the coating inside the rigid... it's probably all water pipe anyway, from the sounds of it.
 

hockeyoligist2

Senior Member
realolman said:
I think sometimes you just gotta bite the bullet.

I think if it was my place, I'd find a way to fix it right, rather than having that hanging over my head all the time.

I agree but...... the "boss" say's that is too expensive to run all new conduit. But with the price of copper now..... he may change his mind the next time. I Hope So!
 

realolman

Senior Member
If I'm reading this right, you're willing to remove all the wires, try to deburr it with something, that may or may not work, and then pull the wires back in and hook it up... and you pretty much know where it's bad.

You wouldn't have to run all new, just deburr it.

I'd fix it.
 

thinfool

Senior Member
Location
Kentucky
Re: burrs in conduit

hockeyoligist2 said:
Not sure if this is the right place to post this.
We have some almost new construction, about 2 years old
,

Did this problem manifest itself within the first year after construction? Virtually all construction contracts require a one year warranty, some are now two, and even five year are not unheard of.

'Course, a guy doing this class of work may have fled the state by now, but if not, your legal folks should have a basis for you to recover whatever costs you have to "make it right". Replacing wire at least 10 times is ludicrous.

If nothing else works and if it would fit, I would ask the AHJ for special permission to pull an armored cable (galvanized steel, not aluminum) thru the conduit.
 

hockeyoligist2

Senior Member
Well, the AHJ is the boss. We don't have any inspections, non profit organazation, not in city limits. We have a constant problem with warrantys. It has to go thru our "engineering dept." and they don't seem to want to follow up. They just say fix it. The contractor is still in town, they hired them to do 2 more upgrades. I'm just a Grunt so I have to do as I'm told! :)
 
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