Electrical Cable - Main Box to Dettached Garage

[RobertsMGB]

Getting ready to run conduit underground for my garage. It's about 25' from the house but I'll need a run of probably 100' to get from my main box to the sub-panel. My main is a 200 amp service and I'll put in at least 60amp service in the garage. I've asked a couple of folks at HD and Lowe's and they don't know the answer - what gauge cable will I need for minimum 60 amp service and that long a run?

 

[simpler=better]

http://www.electrician2.com/calculators/rf_calculator.html

http://www.electrician2.com/calculators/wireocpd_ver_1_parallel.htm

http://www.cerrowire.com/ampacity-charts


Option 1-3/4" conduit(min), 6ga copper THWN w/8ga ground. $2/ft(ish?)

Option 2-NMB in the house and mobile home 2ga aluminum direct bury outside, with the proper copper to alum connectors.

Personally I'd run a conduit from the box to the garage and pull the copper, but that's me. What's eating up 75' of wire in your house?

 

[RobertsMGB]

Yea, that's a long run! Old 1840's farm house. Main box is in the original building and then there's a 40' "wing", then the driveway and then the garage. Rather buy too much then end up a few feet short.

 

[pattenp]

I'd run aluminum 2-2-2-4 SER from main panel to junction box then switch to 2-2-2-4 MHF in 2" conduit for the run to the garage. The #2 Al is good for up to 90A, but using a 60A breaker is fine. This is what I did for power to a detached shop.

 

[TAMPAGT07]

I did something similar, and we ran 6/3...(To run a hot tub, pool pump, and a few outlets.)

 

[pattenp]

I'll just add because you said 60A at a minimum, the cost of using aluminum over copper is cheaper and you can run the #2 Al and have the headroom for up to 90A with less cost than the copper to just get 60A.

 

[wyliesdiesels]

The SER makes the job easier inside as it doesnt need to be in conduit...

 

[Falcon67]

I'd run aluminum 2-2-2-4 SER from main panel to junction box then switch to 2-2-2-4 MHF in 2" conduit for the run to the garage. The #2 Al is good for up to 90A, but using a 60A breaker is fine. This is what I did for power to a detached shop.

Same here, my run is on a 70A breaker because they had one in stock. Total length is 120'.