Insulation Damage While Pulling

[Electrical Underground]

We are on a project and the electrical contractor was pulling in a 480v 3 phase 400A 520' long parallel 350 MCM pull into the building. During the pull at about the 250' mark, one of the conductors slid off the pully and sliced the insulation to the copper. The electrical contractor attempted to repair the damaged insulation on the conductor with a combination of heat shrink and liquid electrical tape and not tell anyone. Once we were made aware we told them they had to replace the conductor. Other than best practices where can I find in the code book that this is not acceptable?

 

[roger]

You won't find it. Damaged insulation properly repaired (note properly repaired) is not a code issue. Whether the repair is acceptable is another issue.

Roger

 

[Electrical Underground]

My concern was mainly any repair that can be done, is it rated to then be pulled into a conduit. Any input on an acceptable repair?

 

[hillbilly1]

If the damage is repaired, usually that wire gets flipped to being the neutral if that run contains one. I would request a mega ohmmeter test though.

 

[James L]

I wouldn't want to tell anybody if I sliced open a 500 ft piece of 350

I'd repair it with heat shrink and, just like @hillbilly1 said, swap that one to be the neutral

 

[hillbilly1]

Might also be in the job specs.

 

[Dsg319]

We are on a project and the electrical contractor was pulling in a 480v 3 phase 400A 520' long parallel 350 MCM pull into the building. During the pull at about the 250' mark, one of the conductors slid off the pully and sliced the insulation to the copper. The electrical contractor attempted to repair the damaged insulation on the conductor with a combination of heat shrink and liquid electrical tape and not tell anyone. Once we were made aware we told them they had to replace the conductor. Other than best practices where can I find in the code book that this is not acceptable?

Metallic or non- metallic raceway?

 

[hillbilly1]

Metallic or non- metallic raceway?

If it’s non-metallic, it will most likely be in the slab, so inevitably, it will be full of water, wether by condensation, or leakage at the joints. Would be harder to get a true megger reading at this time while the pipe is dry!

 

[Dsg319]

If it’s non-metallic, it will most likely be in the slab, so inevitably, it will be full of water, wether by condensation, or leakage at the joints. Would be harder to get a true megger reading at this time while the pipe is dry!

That is very true. I’ve come to find out it’s easier to keep water in pvc conduit than it is out lol

 

[LarryFine]

That is very true. I’ve come to find out it’s easier to keep water in pvc conduit than it is out lol

I don't know why, butthat reminds me of:

"Imagine that! It never occurred to me to think of space as the thing that was moving!"~ Scotty in Star Trek (2009)

 

[Dsg319]

I don't know why, butthat reminds me of:

"Imagine that! It never occurred to me to think of space as the thing that was moving!"~ Scotty in Star Trek (2009)

Haha! Idk wether to take that as a good thing or a bad thing

 

[hillbilly1]

I always liked this Scotty quote;
Scotty: The more they overthink the plumbing, the easier it is to stop up the drain.

 

[retirede]

I always liked this Scotty quote;
Scotty: The more they overthink the plumbing, the easier it is to stop up the drain.

“It’s these Klingon crystals!”

 

[Electrical Underground]

If it’s non-metallic, it will most likely be in the slab, so inevitably, it will be full of water, wether by condensation, or leakage at the joints. Would be harder to get a true megger reading at this time while the pipe is dry!

It is PVC, underground in Florida, it will be in water6-8 month a year.

 

[growler]

Whether the repair is acceptable is another issue.

Roger

I have never had to repair a slice in cable insulation for underground so I'm not sure what would be acceptable.

The only thing I can think of would be to call the cable manufacturer and ask for a correct repair.

If it wasn't underground and exposed to moisture that liquid electrical tape and heat shrink would probably work just fine as insulation but I'm not sure if it would keep all the moisture out (over the long run).

 

[roger]

The only thing I can think of would be to call the cable manufacturer and ask for a correct repair.

Exactly what I would do.

Roger

 

[hillbilly1]

Many years ago I was pulling seven sets of 500’s, about 300’ runs, half way into the reel the cable was gashed from the factory. Found several reels like that. Had to pull it out with a Lull and replace it.