Running Power to Detached Garage

   #1  

Pettrix

Gold Member
Joined
Jan 17, 2012
Messages
482
Location
High Desert Southwest
On a future house/detached garage build. The main power will come underground (PVC electrical conduit) to the house panel which has to be placed outside (per code). For my detached garage, I would just run another conduit line with Romex from the house panel, back underground to the garage and bring the line under the slab or through the garage wall?

Should I have another sub panel inside the garage or just use the main house panel and connect the Romex lines to that?
 
   #3  

MossRoad

Epic Contributor
Joined
Aug 31, 2001
Messages
48,338
Location
South Bend, Indiana (near)
Tractor
Power Trac PT425 2001 Model Year
It depends. For example, where I live, you are allowed to run 1 circuit to an outbuilding from the main building. So if you only want lights, a garage door opener, and a few outlets, one 20 amp circuit would be fine.

If, however, you want more than 1 circuit, you are required to install a sub-panel at the garage. That's still technically running 1 circuit from the main building to the out building. It's just a large enough circuit to split it out into smaller circuits at the sub-panel.

The reason for this is they don't want multiple electrical paths between the buildings.

So, best to check with your local building department to make sure what you want to do is up to their codes.
 
   #4  

Diggin It

Super Member
Joined
Aug 12, 2018
Messages
9,847
Location
Three Posts A Day. Or less.
Tractor
LS MT125 TLBM
And beyond all that, no to Romex. THHN, UF maybe. I ran 12/2 w/ground UF but I will be replacing someday with 10/2, maybe 10/3 if prices ever get back close to sanity. Couple bucks a foot ain't a happenin'.
 
   #5  

ponytug

Elite Member
Joined
Mar 27, 2007
Messages
2,614
Location
Bay Area, CA
Tractor
Power Trac PT1445
Technically, you run wire in the conduit, not romex. (Heat buildup issues.)

If it were me, I would run pretty heavy gauge wire over to the garage to accommodate future uses like power tools, freezer, air compressor, welder... even if you don't use it, the next owner might. I would also consider that there might have an electric vehicle in the garage's future, which might take 40-80Amps. Even if you don't pull big enough wires for that, I would put in the conduit for all of that demand today. Conduit cost is trivial compared to everything else, and retrenching is a pain.

Just free advice...

All the best,

Peter
 
   #8  

Diggin It

Super Member
Joined
Aug 12, 2018
Messages
9,847
Location
Three Posts A Day. Or less.
Tractor
LS MT125 TLBM
Well, yes, I'd also be running at least two additional conduits not less than 3/4" for future use like data, phone, cable TV, etc.
 
   #9  

gary49

Silver Member
Joined
Nov 27, 2012
Messages
157
Location
free union, va
Tractor
Fordson Super Dexta
I‘m getting more and more calls from customers about wiring for electric car chargers. I would recommend a minimum of 1 1/4” PVC conduit between the main panel and the garage. That allows you to install conductors for a 100 amp service.
 
 
Top