Using a standard junction box as a pull point in a run. Do I need to leave a loop of wire in the box or should I take the slack out?

Question

Have a Junction box, as a " pull point" in a run, do I need to leave a loop in my wire in the pull point Junction box?

Answer 1

A little bit of extra wire doesn't hurt, particularly since there could be situations where you end up needing a few extra inches and that saves you from having to replace or splice a wire.

More generally useful is to add a pull string for future use through the entire conduit, such as this Ideal from Amazon:

Answer 2

Providing a loop is not required. It is allowed and can be helpful but excessive wire length may cause your box fill allowance to be exceeded:

NEC 314.16(B)(1) Conductor Fill. Each conductor that originates outside the box and terminates or is spliced within the box shall be counted once, and each conductor that passes through the box without splice or termination shall be counted once. Each loop or coil of unbroken conductor not less than twice the minimum length required for free conductors in 300.14 shall be counted twice. The conductor fill shall be calculated using Table 314.16(B)(1). A conductor, no part of which leaves the box, shall not be counted.

I try to loop at least one wire that I can use and re-use as a potential pull wire. I usually loop the equipment ground since it has a peculiar 4:1 count adjustment that reduces count impact.