Required Box Size?

[nwav8tor]

I want to make some romex wire connections in a plastic box mounted in the attic ceiling. It'll be one 14-2 with ground incoming power connecting to three individual 14-2 w/grnd switch runs connecting to three 14-2 w/grnd lighting runs. Total will be seven 14-2 romex cable ends (14 individual #14 insulated wires and 7 uninsulated grounds). The wires will be secured using 5 plastic wire nuts and 1 or 2 cu ground crimp clamps. Just how big must the box be for all this?

A little app on my smartphone says 16 cu in for seven 14AWG wires with 14 AWG ground.

For fourteen 14AWG wires with 14AWG ground the app says 30 cu in.


Since the app just enters # of wires and doesn't specify romex, am I correct in assuming I need a box larger than 30 cu in ?

Thanks,
paul

 

[pattenp]

The 30 cu in. is correct. The Romex sheathing only enters the box by at least 1/4", so only the conductors are counted. But that is code minimum. You may want to use a little bigger box for ease of use.

 

[mrjaw14]

what pattenp said.....make life easy on yourself and get a bigger box.