Mixing wire gauges/circuits in same box

Old 06-26-14, 03:16 PM
Thread Starter
Join Date: Nov 2013
Posts: 213
Upvotes: 0
Received 0 Upvotes on 0 Posts
Mixing wire gauges/circuits in same box

I have a junction box in the basement that contains wires from 3 circuits. a 15a,20a and a 30a. Is it bad practice to have mixed gauges (or multiple circuits for that matter) in the same junction box?

Last edited by pcboss; 06-26-14 at 03:44 PM.
Old 06-26-14, 03:52 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 14,151
Received 809 Upvotes on 682 Posts
Nope. It is done all the time and is A-OK. In commercial jobs we have installed j-boxes, and seen others installed, that have 30+ circuits in them.
Old 06-26-14, 03:52 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 13,933
Received 180 Upvotes on 158 Posts
Mixed circuits are fine in the same junction box. All the grounds need to be spliced together.
Old 06-26-14, 11:39 PM
Justin Smith's Avatar
Join Date: Dec 2010
Location: Cressona, Pa, USA
Posts: 2,272
Upvotes: 0
Received 1 Upvote on 1 Post
Not a problem. Just yesterday I had a J-Box with 4/0 Aluminum on a 200A breaker all the way down to #12 copper on a 20A breaker all in 1 box.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: