Sub-Panel? Junction Box? Impossible? Help.


Old 04-10-16, 02:23 PM
Thread Starter
Join Date: Apr 2016
Location: USA
Posts: 1
Received 0 Votes on 0 Posts
Sub-Panel? Junction Box? Impossible? Help.

Hello! Greenhorn to the forum. I've been reading a lot of threads and posts and can't quite find what I'm looking for. Here's my situation. I have a 1200 square foot shop about 20 yards from my house. I have a 40 AMP line that goes into the shop and all electrical outlets are on that line which is activated by a single light switch. When I flip that switch everything comes on. What I would like to do is create 4 separate lines (romex) with electrical outlets on each line and each of those 4 lines go into their own light switch. So if I want the orange line (see diagram) and outlets on that line to be one, I flip the switch. If I want the blue and orange lines on, I flip their corresponding switches. There are times when I only want to use one side of the shop and it's electrical outlets and therefore don't really need the other lines on. Does that make sense? So I have one 40 AMP electrical line coming from the house, into the shop up to 4 light switches that will turn on their corresponding electrical lines. I have made a terrible (thank God I'm not an artist) diagram which I hope explains it? So, is that a sub-panel, a junction box, a really stupid idea? Any help would be appreciated.
Attached Images  
Sponsored Links
Old 04-10-16, 02:34 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,493
Received 33 Votes on 25 Posts
Since general-purpose circuits (lights and receptacles) cannot be protected at more than 20 amperes you need a sub-panel to break it down to multiple 20 ampere circuits.

You probably need a lot more but you at least need that. What voltage do you have and how many individual wires in your 40 ampere circuit?
Old 04-10-16, 02:51 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,946
Received 32 Votes on 27 Posts
Once you install the sub panel you can use a breaker as the switch. You would just need 4 circuits.
Old 04-10-16, 03:41 PM
ray2047's Avatar
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
Not quiet clear. Very important:
  • Do you have four wires from the house, two hot, nor neutral, one ground?
  • Is it wire or is it cable from the house?
  • If cable is it NM-b (Romex) or UF (gray jacket)?
  • Is the size of the wire or cable at least #8 (except for ground)?
  • If wire is it in PVC conduit buried at least 18"?
  • If cable is it direct buried 24"?

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
Display Modes
Ask a Question
Question Title:
Your question will be posted in: