Sizing a sub-panel

Reply

  #1  
Old 02-28-16, 02:03 PM
Member
Thread Starter
Join Date: Feb 2016
Location: United States
Posts: 5
Question Sizing a sub-panel

Location: Firestone, CO (about 25 miles north of Denver)

I'm trying to figure a reasonable guess at a sub-panel size, given current and future projects it will need to support, given my current main panel is essentially full. I'm not an electrician.

My main panel is a 200 amp service.

My current project is to add the sub-panel in my garage, which will support adding circuits for my woodworking machinery. I am a hobby woodworker, so I'm very unlikely to be running multiple machines at the same time, other than a machine and dust collection. I run 20amp circuits for my machinery, and when I'm using two machines, I ensure that one is on one circuit and the other is on a second circuit. I'll also be adding at least one 220V circuit for a new table saw (3 or 5 hp, so 13 or 20.5 Amp rating). I may convert a couple other machines to use 220, since they purportedly run better on 220.

The second project, a kitchen remodel, will actually reduce power needs, since we will be replacing an electric range with a gas range.

The third project will be a basement remodel. There will be a home theater, a computer room, my wife's sewing and (machine) knitting room and a bathroom (3/4), all with electric floor heat under hardwood flooring (carpet in home theater). Some area will remain unfinished storage space.

I don't mind if the consensus overestimates my needs, because I'd rather have enough than not so. Any thoughts?

Thanks,
Eric
 
Sponsored Links
  #2  
Old 02-28-16, 03:12 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,676
Generally you use a 100 amp panel for a sub but usually the breaker feeding it will be smaller than 100 amps. The 100 amp panel is used so you have enough spaces for breakers. If the garage is attached you can use a main lug panel. If detached a main breaker panel. Most panels do not come with a ground bar so you will have to buy and install one.
 
  #3  
Old 02-28-16, 03:41 PM
Member
Join Date: Feb 2016
Location: United States, Virginia
Posts: 781
Just shooting from the hip but you will most likely find a 100A or 125A panel fed with 2-2-2-4 Al SER on a 90A feeding breaker (max) will cover your needs. But the best thing to do is a load calculation and determine what the max amp load you will see at one time on the sub.
 
  #4  
Old 02-28-16, 06:22 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: Twin Cities, MN
Posts: 11,991
The second project, a kitchen remodel, will actually reduce power needs, since we will be replacing an electric range with a gas range
If the range is staying in the same location I suggest leaving the electric feed and receptacle for the range. It would be a good selling point if you ever sell.
 
  #5  
Old 02-29-16, 05:00 PM
Member
Thread Starter
Join Date: Feb 2016
Location: United States
Posts: 5
Thanks, all. I'll also be getting my Brother In Law to help with this, and he has some experience in these matters. But, I figured I'd get a head start on the planning.
 
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
Display Modes
'