wiring to garage subpanel

Reply

  #1  
Old 03-28-10, 09:28 AM
S
Member
Thread Starter
Join Date: Mar 2010
Location: United States
Posts: 22
Received 0 Votes on 0 Posts
wiring to garage subpanel

I need to wire my garage. I have an open 30 amp double breaker and two open 20 amp single breakers in my main panel in the house. I really do not need 240 volt but would like my receptacles an lights in the garage on seperate circuits. Can i just run the two hots, neutral and ground off the 30 amp double, or should I run from the seperate 20 amp to the sub panel, and if so, do they need to be from different sides of the main? What would be the difference and reccomendation. Also wire guage, the run is approx. 100 ft. from main to sub.
 
  #2  
Old 03-28-10, 09:42 AM
C
Member
Join Date: Jul 2009
Location: SE Iowa
Posts: 104
Received 4 Votes on 4 Posts
Is this attached or detached garage?
How old is your main panel (can you replace existing circuit breakers with a larger size)?

If it's just lights and receptacles, a multiwire branch on the 20A double pole breaker would work just fine.

However, I would personally go with either a 30A or 40A run to a subpanel in the garage. This would leave you open to more options in the future (dedicated air compressor circuit), plus much more convenient to reset a breaker that you tripped locally rather than tracking through the house to the main panel.

Good luck.
 
  #3  
Old 03-28-10, 03:58 PM
S
Member
Thread Starter
Join Date: Mar 2010
Location: United States
Posts: 22
Received 0 Votes on 0 Posts
I'm not sure how old it is. It is a square D and was here when I moved in 20 some years ago.
So, if I run from the double 30 amp breaker I could at some time wire a 240 receptacle off the subpanel? What wire gauge would be recommended from main underground to the sub approx. 100 feet?
 
  #4  
Old 03-28-10, 04:28 PM
J
Member
Join Date: Oct 2006
Location: Wilmington
Posts: 4,214
Received 0 Votes on 0 Posts
30A requires #10, but for a long run I would use #8. For a 240 branch to a sub-panel you need 4 wires, 2 hot, neutral, gnd. Neutral and ground in the sub-panel are separated. Ground is bonded to the panel with a ground rod, neutral floats.
 
  #5  
Old 03-29-10, 06:47 AM
S
Member
Thread Starter
Join Date: Mar 2010
Location: United States
Posts: 22
Received 0 Votes on 0 Posts
Thanks for the info. I am surprised at the wire guage. I was thinking 12 or even just 14 based on what the total amp draw might be in the garage. Maybe 12 amps from a table saw and 1-2 amps from lights. Or, is the feeder just have higher requirements for wire gauge? And I can run the 12 or 14 from subpanel to lights and receptracles?
 
 

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