double check me electrical

[tigerwolf67]

So i have read several posts about this topic but I want to double check my situation, so here goes:

I bought a house, it has a detached garage/shop with a 2 car carport, the house has a standard circuit breaker panel 200 amp i am guessing, there is a 100 amp sub panel in the garage. The main panel has a 100 amp circuit breaker for the garage, however the service line was never ran. The garage is currently running off a 20 amp line that powers the carport light. The only thing in the garage right now is lights and some receptacles. distance between the 2 boxes is about 120' with most of that being the house since the main panel is on the opposite side of house. The previous owner simply never ran the line.

Here is my plan:
I am going to run a line using some 2-2-2-4 aluminum service entrance cable from Lowe's, hook it up to the 100 amp circuit breaker and run the cable thru pvc conduit thru the attic of the house out the gable and into the shop to the sub panel. I know the SER cable cannot be buried but it is jacketed for indoor use, from there I am going to run a 50 amp line to the side of the garage for my travel trailer and i would like to install a 220 receptacle in the shop just in case i ever need one for a welder or air compressor.

does this plan sound feasible and is there any thing i am missing. Thanks

 

[unsinkable]

#2 al is fine, but only good for 90 amps, change breaker.
voltage drop should be acceptable at that distance. You don't need conduit, just run it thru attic supported nicely.
You don't list your location, if it gets real hot in that attic you might want to go up a size on wire, de-rating wire at high ambient temps. (using larger cable also lowers usage cost a bit)

 

[tigerwolf67]

Sorry, I am in north Mississippi during the summer it averages about 95 to 100 degrees, I am also going to install a thermostat controlled power roof vent, but that will be seperate from the garage wiring. Stepping up a size would be a 4/0-4/0-4/0-2/0, is that correct.

 

[wyliesdiesels]

Is the garage attached or detached? U indicated that u would run the wire through the attic. This implies that the house and garage are connected. Are they connected via a breezeway?

Yes its a good idea to upsize the wire for high ambient temperatures....

Make sure the neutral bar is isolated in the subpanel. U may need to buy a ground bar kit.

 

[pattenp]

From 2-2-2-4 SER, 1-1-1-3 is the next size larger in SER.

 

[tigerwolf67]

Yes there is a breezeway, about 5 five wide, I plan to run the cable thru pvc conduit in the breezeway until it drops back down into the garage. Any ideas on where to get the 1-1-1-3 SER by the foot, Lowe's does not seem to carry it. and I don't need a 500' roll obviously.

 

[woodzy]

You should look for an electrical supply house in your area. The will sell it to you by the foot.

Google is your friend.

 

[tigerwolf67]

Yeppers I found some, actually from Home Depot, surprised they have it and lowes does not. Anyway thanks for the suggestions, sounds like I am on the right track.

 

[wyliesdiesels]

Yes there is a breezeway, about 5 five wide, I plan to run the cable thru pvc conduit in the breezeway until it drops back down into the garage. Any ideas on where to get the 1-1-1-3 SER by the foot, Lowe's does not seem to carry it. and I don't need a 500' roll obviously.

I wouldnt bother with PVC as SER doesnt need to be ran in conduit unless its subject to damage. Plus its a pain to pull through conduit.