Yet another sub panel question...

[Jeff396]

I am basically in the same situation as Elmo on the other sub panel thread. I am in the process of finishing my basement and I need to install a sub panel as my main 200 amp panel is full. My question is how do I decide how many amps I need at the panel and what is ovekill.

My basement is about 3000 square feet which includes a 2 car garage with a shop, a bedroom, mainroom, bathroom, stairwell and a 20x25 hobby room. I have used the formula where you multiply your square footage by 3 and divide by 230v to get your light and plug needs. That comes out to about 40 amps. My question is how much over should I go to allow for the tools I might get to use in the shop? I already have a 220v 30 amp circuit run for my compressor and that will remain in the main panel. Would a 60 amp panel with 20 amps available be enough to handle any tools I might get or should I think bigger? /forums/images/graemlins/confused.gif

Jeff

 

[Wood_Butcher_Dav]

My thoughts would be to put at least a 100 amp box. You never know what you might need in the future. Welder, hot tub, steam room etc.

Dave

 

[MDNick]

Whole heartedly agree with the butcher. It is relatively cheap to do 100 amps now. Later when you want more power (we always want more power!) it will already be there. Having said that though, 100 amps is a lot of power. And may be total over kill for you. I can't fathome overkill, though. /forums/images/graemlins/laugh.gif /forums/images/graemlins/grin.gif

I beieve the maximum you can pull per code is 100 (50% of your main panel).

 

[Jeff396]

Thanks for the replies! According to the other thread and what I've read I will need to run 3 #2 guage copper wires and an 8 guage ground wire for a 100 amp sub panel. Is there such a thing as 2-3 with a ground or do I have to purchase each wire separately? When I quickly looked at the local Lowes all I saw was 2-2-2-4 but it was aluminum.

Jeff

 

[Inspector507]

Jeff,
They make #2 3-conductor Romex with ground. But the
2-2-2-4 AL SER cable is commonly used to feed a 100A subpanel.

 

[tdenny]

Jeff,

My basement is only 2200 + square feet and I had a 100 amp sub-panel put in when we built the house. That was the size my builder recommended.

 

[Jeff396]

Assuming I can get my hands on the #2-3 romex with ground also, is this a 6 of one half dozen of the other choice of wire or is one preferable to the other? I'll be going about 50 feet with it.

Jeff

 

[Inspector507]

I have no idea on prices, but my own preference would be the Romex. The SER style cable is perfectly fine in it's own rite though.

 

[Jeff396]

Thanks everyone! Hopefully Lowes stocks the 2-3 romex and I will be well underway.

Jeff

 

[Redfisher]

/forums/images/graemlins/smile.gif I would use a 60 amp panel. I have 2 shops that run on 60 amps. My compressors also run on this along with welders. You already have yours on the main panel. Most people tell you to go bigger because they do not understand total wattage. This is what counts not amps. You can only run so much yourself at a time. To go with a 60 amp will reduce your costs greatly. The wire size will be # 6. Also another note that no one has mentioned is you must make sure that the ground screw is removed so the sub panel netural is not boned to ground. This only should happen at the main panel. I would recommend a Square D panel as the breakers are the best protection on the market. You can decide on the number of circuits. Hope this helps.