Using an Insulation Piercing Connector on old (30+) year wire. Issues?

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cdherman

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Tapping off a existing 200A exterior enclosure. Tapping after the 200A main breaker, and I will certainly be throwing that breaker (having read that you *can* use the IPCs on energized lines, I still find that foolhardy if one has the choice!). I could use a Polaris style connector, but that would involve messing with old stiff wiring, making cuts etc. Just trying to do it right with the least effort and cost.

Issue is the wiring is definitely not new. 2/0 Copper THHN I'm guessing 20+, perhaps 30+ years. I took pictures when preparing for the job, but no pics have a date on the wire.

I am worried the insulation has gotten hard and could impair the teeth of the IPC from penetratingly properly. To that end, I was thinking that I might bring a heat gun and warm things up a tad. Within reason of course. It is February.....

Once things are up, this will feed a 100A hardwired Ford Lightning EVSE that will pull 80A. I was thinking I would measure my voltage drops across the IPC for good measure under load. I would think that since this a point source of resistance, I should tolerate only zero drop in voltage. I played with the calculations and even a 1v drop over the connection would be generating 80w of heat!! At 80A and 240v....

I've done a bunch of 50A circuits (40A derated) for EVSEs, but not one this large.

Oh for anyone curious -- Ford specifies #3 copper as the wire. So that's what I am using.
 
Your plan sounds reasonable. I also de-energize first if practicable, but that's their primary purpose.

They are safe to install energized as long as your tap has no load. The conductive parts are isolated.
 
20-30 years is not really that old in my book. But I personally don't care for IPCs and would probably use a double entry Polaris large enough to pass the 2/0 all the way through.
 
jaggedben said:
20-30 years is not really that old in my book. But I personally don't care for IPCs and would probably use a double entry Polaris large enough to pass the 2/0 all the way through.
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In the intervening 30 minutes or so, over an adult beverage, I have came to the same conclusion. Funny that scotch doesn't always make me make bad decisions!

There is an outbuilding on the property that someone fed by sticking a second wire off the lug of the main 200A breaker. Just a little 12g 20A circuit. I didn't want to "be that guy" that tells the owner he needs to fix old work that was not done perfectly. And its clearly been there for a long time. But putting a 4 port double entry polaris would kill 2 birds with one stone. Maybe not the best analogy, ha ha......

Question: I was reading elsewhere about taps after the main breaker, and one post suggested that the guy should use heavier wire between the breaker and the taps. This makes no sense to me. The 2/0 wire is sized to the breaker. The main breaker is the limiting factor, not the short piece of wire between it and the tap(s). Or is there some code that I am un-aware of?
 
I've installed a handful on old copper and aluminum thw feeders with no issues. Usually energized too.

Definitely prefer a Polaris, H tap, or C tap. But there's really shine when there's no room to really fit anything else. Especially in the old troughs with 40 split bolt taps feeding disconnects.
 
IPC's in general safe to use on energized conductors.
My concern would be if you are already concerned over the insulation of the existing wire and breakage if bending, I would be recommending replacement of exising wire. Unlike most peoples belief that the wiring is of unlimited life the mfg does indeed prescribe a limit, not necessarily to the wire (copper of Aluminum) but to the insulation. Most indicating 50-70 yrs, but sometime more or less depending on loads over time that may have caused heating, EV exposure, Exposure to corrosive enviroments, etc.
 
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