I sometimes have to Cad Weld grounding electrode conductors and was wondering if it was a violation to join phase conductors with a Cad Weld. I have never seen this done.

My thinking was if it's good enough for grounds why not hots, or am I just looking for a reason to play with smoke and fire?
Bob

I would worry about the heat from the welding process being conducted along the wires, and damaging the insulation on both sides of the splice.

I have cadwelded a lot of ground connections, but they always involved BARE wire....

Let me point out that I do not plan on doing this.

It was a thought that I had while I was working.

But you make a good point that a AHJ could say I damaged the insulation.

Seems like the effort needed to restore a foot-and-a-half of cable insulation and competent taping of the ragged mold overspill would obviate such a practice.

Can’t imagine producers of exothermic-weld materials having any intention of them used in that way.

{No offense intended.}

About 5 years ago, a fellow worker had the same thought. So we used some scrap 350MCM and tried it. The THHN insulation was burnt and melted back bout 3 feet on each wire. To reinsulate would have been time consuming and expensive, not to mention look bad.
Oh well that experiment did not go the way we hoped. oops.
Cadwelds are great on bare wire only.

nesparky, Thanks I wish I got to see that, I did not think the damage would travel back that far, I was thinking 12 to 18 inches.

Article 250 covers the "exothermic welding process" and 110.14(B) covers splices.

Here's that rule:


I sure hope this isn't interpreted to mean that welded splices are OK for insulated conductors!

Interesting question. Maybe the code needs to be revised.

I didn't read the NECH commentary, maybe it has some more explanation on what is meant by "welded"??