Subpanel Minimum Distance From Main Breaker


Old 03-02-17, 07:20 AM
Thread Starter
Join Date: Jan 2015
Posts: 26
Received 0 Votes on 0 Posts
Subpanel Minimum Distance From Main Breaker

Hi, I cant find info on this online - I was hoping to add a subpanel next to my main breaker to have more open slots. Is there a minimum space required between the main box and subpanel box? Can they be just a couple inches apart?

Also, is there a required buffer of plywood behind the box from the edge of box to the end of the plywood?

Its a tight fit with the current chunk of plywood which is why I ask.

Last question.. I see the breaker going to the panel needs to be less than the main breaker. The main is 100amps, does that literally mean I need something less than 100 or can I also use a 100 amp breaker in the subpanel?
Sponsored Links
Old 03-02-17, 08:40 AM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
There only needs to be enough space so the covers can fit correctly, generally about 3" is standard. Plywood or other structural mounting surface is up to you as long as it is securely fastened. Plywood is often used because it provides a convenient surface to staple NM cable entering the panel.

A subpanel must be less than or equal to the ampacity of the feeding panel, so you can do up to 100A.
Old 03-02-17, 08:58 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,997
Received 40 Votes on 35 Posts
Check the bus stab ratings on your panel. you cannot exceed those ratings.
Old 03-02-17, 09:38 PM
Join Date: Feb 2017
Location: U.S.A.
Posts: 54
Received 0 Votes on 0 Posts
Consider tandem or duplex breakers

Depending on your needs and the current panel, you might be able to substitute tandem or duplex breakers for some your current breakers to get more circuits into your current panel. Be sure to check panel specs for details.

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:
Your question will be posted in: