2 different circuits in same double gang box

Old 04-18-04, 04:22 PM
Thread Starter
Join Date: Mar 2001
Location: Connecticut
Posts: 706
Upvotes: 0
Received 0 Upvotes on 0 Posts
2 different circuits in same double gang box

I am adding another switched lighting circuit to an existing box, which i will make a double gang.
I believe that is not a code problem, but should I keep the grounds in the box separate for each circuit, or should i tie all the bare ground wires for the 2 circuits together?
Old 04-18-04, 05:16 PM
Join Date: Sep 2002
Location: welland ontario
Posts: 8,002
Received 501 Upvotes on 411 Posts
Tie all the grounds together.
Keep the white wires separate from the 2 circuits.
Old 04-19-04, 06:03 AM
Join Date: Sep 2003
Location: Central New York State
Posts: 13,246
Upvotes: 0
Received 0 Upvotes on 0 Posts
With residential electric you always tie the ground wires together in a junction box, regardless of which circuit they came from. It is only hot and neutral wires that you keep separated by circuit.

To comment further, some people do not recommend what you have done and consider it unsafe. They frown on this because there is the possibility that someone might turn off a breaker to one circuit but leave the other breaker on when accessing one of the switches in the box, thus leaving open the possibility of electrocution. My suggestion is to make sure that you mark the breakers so that someone will at least be warned that the breakers power devices through a common junction box.
Old 04-19-04, 07:52 AM
Visiting Guest
Posts: n/a
This is done all the time and is code-compliant. One particular place that comes to mind is next to a kitchen sink. A double gang box holds a switch for the light over the sink and one of the small appliance receptacles.

As was previously mentioned, twist all your bare or green grounds together and secure them with a crimp-cap or wirenut.

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