Fixing Damaged Wire
- Thread starter Brewer
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Re: Fixing Damaged Wire
At the minimum, I would check the mfg literature to see if the repair method/material is identified for the the intended use.
Next, look at the area of installation:
For example, I would consider pulling a taped over insulation nick into a conduit as an explicit act of aggression.
On the other side, I have repaired cable jackets in a cable tray using a 3M product identified (by 3M) for the the purpose. Worked great.
If the copper is not showing, then some insulation thickness determination is in order. My inclination is that if I thought it needed tape, then it comes out.
I can tell you what it costs to have that kind of a cable (big, high short ckt current) fail in a couple of years when the moisture gets past the tape.
carl
[ January 05, 2006, 03:45 PM: Message edited by: coulter ]
Well, consider Art 110.2, 110.3, 110.7, 110.11, 110.12, ...
At the minimum, I would check the mfg literature to see if the repair method/material is identified for the the intended use.
Next, look at the area of installation:
For example, I would consider pulling a taped over insulation nick into a conduit as an explicit act of aggression.
On the other side, I have repaired cable jackets in a cable tray using a 3M product identified (by 3M) for the the purpose. Worked great.
I assume you mean in conduit. If there is copper showing, no question. Pull it out, replace it, unless your repair can meet the criteria listed above. "But that is really expensive," Yes, that's true. Bummer.
If the copper is not showing, then some insulation thickness determination is in order. My inclination is that if I thought it needed tape, then it comes out.
I can tell you what it costs to have that kind of a cable (big, high short ckt current) fail in a couple of years when the moisture gets past the tape.
carl
[ January 05, 2006, 03:45 PM: Message edited by: coulter ]
Re: Fixing Damaged Wire
Here is the worst case I have had happen.
I had a fire pump run to replace, 4 paralleled 350kcmil in 3" conduits, 750 feet. We were in a hurry so I bought the cable and had it shipped in while arranging for a contractor. The cable showed about the same time as the contractor and they set up and started pulling. We meggered after all cables were installed and one cable in one run failed. Pulled it out. It was obivious it had been forked while on the reel. Contractor took himself out back and slapped himself around the block for missing the insulation cuts while they were pulling. I called the supplier and said, "Hey, you owe me some wire, and I need it right now. and I want all three cause I'm not pulling the undamaged two back in." His response was, "Bull****! I owe you one. You missed the cut when you were pulling." The contractor agreed.
I bought two , the supplier bought one and paid the freight on all three, the contractor paided the labor for the repull. Everybody lost.
Why were we repairing? Cause one run had failed after 4 years, likely due to an insulation failure that passed the original installation megger. The failure ruined the insulation on the cables in the other three conduits.
Why so much damage? It was connected ahead of the main, and it didn't trip the HV xfmr fuses for a long time. (a few seconds)
carl
Here is the worst case I have had happen.
I had a fire pump run to replace, 4 paralleled 350kcmil in 3" conduits, 750 feet. We were in a hurry so I bought the cable and had it shipped in while arranging for a contractor. The cable showed about the same time as the contractor and they set up and started pulling. We meggered after all cables were installed and one cable in one run failed. Pulled it out. It was obivious it had been forked while on the reel. Contractor took himself out back and slapped himself around the block for missing the insulation cuts while they were pulling. I called the supplier and said, "Hey, you owe me some wire, and I need it right now. and I want all three cause I'm not pulling the undamaged two back in." His response was, "Bull****! I owe you one. You missed the cut when you were pulling." The contractor agreed.
I bought two , the supplier bought one and paid the freight on all three, the contractor paided the labor for the repull. Everybody lost.
Why were we repairing? Cause one run had failed after 4 years, likely due to an insulation failure that passed the original installation megger. The failure ruined the insulation on the cables in the other three conduits.
Why so much damage? It was connected ahead of the main, and it didn't trip the HV xfmr fuses for a long time. (a few seconds)
carl
Re: Fixing Damaged Wire
If the wire is dammaged inside the pipe, this is a no brainer.
If the wire is damaged where it can be accessed, then the answer i would give in an open forum is different from what i would actually do.
I would ask the AHJ to come by and have a couple fix options on hand and ask what he/she would consider acceptable.
If he answer is re-pull, then that is just another oppertunity to learn and grow from experience.
If the wire is dammaged inside the pipe, this is a no brainer.
If the wire is damaged where it can be accessed, then the answer i would give in an open forum is different from what i would actually do.
I would ask the AHJ to come by and have a couple fix options on hand and ask what he/she would consider acceptable.
If he answer is re-pull, then that is just another oppertunity to learn and grow from experience.
petersonra
Senior Member
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- Northern illinois
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- Semi-retired engineer
Re: Fixing Damaged Wire
I would be real nervous about a repair where it cannot be inspected.
Maybe the answer is to cut in a box where the repair is and make the repair in the box if that is more cost effective than replacing the wire.
I would be real nervous about a repair where it cannot be inspected.
Maybe the answer is to cut in a box where the repair is and make the repair in the box if that is more cost effective than replacing the wire.
chevyx92
Senior Member
- Location
- VA BCH, VA
Re: Fixing Damaged Wire
First off, what do you mean by damaged wire?? Damaged insulation, conductor damaged, what?? Correct me if I'm wrong but if the conductor is damaged you should repull. Now if its the insulation, it can be repaired with UL listed, rated tape.
First off, what do you mean by damaged wire?? Damaged insulation, conductor damaged, what?? Correct me if I'm wrong but if the conductor is damaged you should repull. Now if its the insulation, it can be repaired with UL listed, rated tape.
macmikeman
Senior Member
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- Planet macmikeman
Re: Fixing Damaged Wire
Worse than that is how about you find a little bit of rat chew up in someone's attic, and you notice there are oversize holes in the top plate where the cables came up through the wall partition. Shine your light down there and can't really see much, but .....
Worse than that is how about you find a little bit of rat chew up in someone's attic, and you notice there are oversize holes in the top plate where the cables came up through the wall partition. Shine your light down there and can't really see much, but .....
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