I had one of four parallels that read 50 amps lower than the other three for some reason. I was there doing an energy management survey for the customer, and it puzzled the engineers that were with me too. I had the customer set up with their local contractor and the poco to investigate. I figured it was probably a bad connection at the transformer. Never heard back what they found.
Most the time I think it ends up close enough that no individual conductor becomes overloaded to any extreme, but yes it isn't easy to obtain exactly same total impedance on each individual conductor of the set.
It also depends on how closely the conductors were sized to the current.
And as far as how much overloading damage may occur can also depend on how long peak demand periods last.
I have never seen anyone check the length of parallel condcutors when they're terminating them. Never seen a problem either.
The only reason I knew was the scrap at the bottom of the pole. I clamped them later just for the S&Gs. Now there may have been some scrap on the other end as well but that doesn't count.
That's the way I learned how to do it.
Everything the exact same length? Not just each phase? The excess was wadded up in the gear.
No, each phase the same length, but yes, excess wire from the shortest pipe compared to the longest snaked around the inside of the gear.
Yes that is the way I do it and it is what the code says. It might not be pretty, but code says same length. In my experience, most electricians ignore the same length rule.
Unless the run is extremely short the rule can be ignored without peril. If you have 750 kcmil to terminate good luck losing a few feet.
Yeah, that’s fine, but they pulled ALL conductors the same length, and didn’t cut any off. They didn’t understand that parallel conductors should be same length meant each phase, not all conductors! LOL!
Actually I recently ignored it when replacing a 1200A switchboard with a PB where I reused the 2 sets of 750 CU from the CT can. 750 CU is not super happy fun time. I admit I have gotten more lax with ignoring this rule. In my earlier days I would lay the conductors out and cut them the exact same length and not be able to make an art project out of it. About 5 years ago I did a new 1200A and I used a 36x36 pull box instead of LB's and I did cut each phase the same length and stuffed the extra in that box.Unless the run is extremely short the rule can be ignored without peril. If you have 750 kcmil to terminate good luck losing a few feet.