Splicing Power Feed Wires in Junction Boxes

Lloydo

New member
Hello, I was wondering if the NEC has information or if there are best practices in how to make a splice of large gauge 480VAC wires, like 250MCM, in an industrial manufacturing environment. What hardware and taping method to contain/protect/insult the splice is what I am mainly interested in.
 

iwire

Moderator
Staff member
I was wondering if the NEC has information or if there are best practices in how to make a splice of large gauge 480VAC wires, like 250MCM, in an industrial manufacturing environment. What hardware and taping method to contain/protect/insult the splice is what I am mainly interested in.
The NEC only tells us what we cannot do, it does not recommend. The NEC specifically states it is not a design specification

90.1 Purpose.

(C) Intention.
This Code is not intended as a design specification
or an instruction manual for untrained persons.
Beyond that there are many ways to splice larger conductors, it really becomes a mater of personal choice of the designer or installer.
 

K8MHZ

Senior Member
Polaris taps or split bolts with ample amount of tape are two methods.

ps:The image of Polaris taps is originally from infinity I believe

Having used both, I strongly recommend the Polaris type connectors. When I used split bolts on large conductors, my math was always wrong. I couldn't come up with a way to use one hand to hold one wire, one to hold the other, one to hold the pair of dogs holding the saddle of the split bolt, one to hold the wrench to turn the nut of the split bolt and the other hand holding onto the ladder.

With Polaris (I think Illsco also makes them) connectors you can do one wire at a time, plus there is no need to gob up the connection with tape.
 
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