Two separate, yet different circuits in one box

Reply

  #1  
Old 03-04-20, 08:34 PM
D
Member
Thread Starter
Join Date: Mar 2020
Posts: 3
Received 0 Votes on 0 Posts
Two separate, yet different circuits in one box

Would I be NEC and/or NFPA 70 compliant if I put an old 1950's circuit (3 way wire, no available/useful ground 14/2) in a new UL classified plastic switch box, with a new circuit (14/2, plus ground)? Each circuit controls a switch for a light, and the new deep double gang box is rated at 34.6 cu. in. I tried looking for the code, but just couldnt find the detail / answer. My alternative if this is not within code, will be to use separate single boxes on each side of a stud. Thank you.
 
Sponsored Links
  #2  
Old 03-04-20, 09:13 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 59,638
Received 1,167 Votes on 1,082 Posts
Welcome to the forums.

You are allowed to run a separate ground wire to the two wire circuit.
You are keeping the old circuit and the new circuit separate.
You can use the ground from the new circuit to ground the new two gang box and devices.
 
  #3  
Old 03-05-20, 04:09 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 15,172
Received 91 Votes on 78 Posts
There is no issue with multiple circuits in one box.
 
  #4  
Old 03-05-20, 11:09 AM
D
Member
Thread Starter
Join Date: Mar 2020
Posts: 3
Received 0 Votes on 0 Posts
Thanks pj.. and pc.. for your timely replies. Guess also having a live circuit in the gang box when only one of the two circuits is turned off is not an exposure. Is it ok to put a tag in the box stating there are two separate circuits, or is it an electricians good process that discounts the need? Thanks again in advance.
 
  #5  
Old 03-05-20, 12:32 PM
T
Member
Join Date: Oct 2005
Location: USA
Posts: 1,648
Received 43 Votes on 42 Posts
I have only seen such kind of warnings where there is two or more energy sources; as in, generator, UPS vs street power. Two or more branch circuits in a single box is not unusual.
 
  #6  
Old 03-05-20, 02:41 PM
L
Member
Join Date: Nov 2015
Posts: 1,497
Received 83 Votes on 72 Posts
There is no need to put a tag. As long as a qualified person is working on the circuit, he/she should know.
This is very common practice for 2 gang switches controlling 2 different sections and garbage disposal and receptacle sharing same junction box (2gang).
Just be sure not to tie neutral from 2 different circuits together. Ground should be tied together though.
 
  #7  
Old 03-06-20, 09:39 PM
D
Member
Thread Starter
Join Date: Mar 2020
Posts: 3
Received 0 Votes on 0 Posts
Yeah, no neutral tie, as they then wouldnt be separate circuits.

Good here then; Thanks again to all...
 
  #8  
Old 03-07-20, 09:58 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 59,638
Received 1,167 Votes on 1,082 Posts
I have put notes on the back side of the device plate.
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


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