Adding a main panel in the garage

[xbanone]

I have 100amp serivce in my home. I will probably have to eventually upgrade to a 200 amp service, but for the time being I would like to start the electrical work in the garage sourced through the house panel.

Here is my plan, please let me know if there is anything I could do better. I bought a Square D 100 amp main panel for the garage that will be used as a sub panel. The electric needs in the garage will be minimal at first, between 8and 12 4' T8 lights, several basic 110v outlets and maybe 2 outside lights.

Should I feed the garage panel with a 40a or 60a breaker? I assume I can leave the 100a main breaker in the new box? Am I getting close to overloading the household 100a service? (Dryer/AC/ everything else is gas in a 900 square foot home).

Thanks

 

[mrb]

I would supply the garage with 60 amps. Dont run your dryer, AC, and weld all at the same time.

Is the garage attached or detached?

 

[xbanone]

I would supply the garage with 60 amps. Dont run your dryer, AC, and weld all at the same time.

Is the garage attached or detached?

Thanks for the quick response. The garage is detached, 850sq feet, (almost as big as the house). I will have to be careful to make sure I only run one large appliance at a time. Currently the A/C is on a 40a breaker and the dryer is on a 30a.

 

[Falcon67]

Our house panel is 100A and the line feeding the shop is 60A. However - the shop feed is double tapped off the meter can, not out of the house panel. IF it's allowed - maybe not - look into that possibility. It'll extend the life of your house panel. Or look for a replacement meter can that is made for more than one tap out. That would let you run your full feed to the shop now and be done with it.

On the rest, I would run wire sufficient to handle the 100A garage panel and then fuse it down. Your only issue would be whether the breaker in the house panel will accept the wire size running to the garage. One possibility would be to mount a 100A disconnect next to the house panel and run the shop feed to that, then a smaller wire size to the 40A breaker in the house panel.

 

[tfi racing]

Just run wire/cable suitable for 100A and the 100A breaker if it fits in your panel,and of course your local rules allow it(it helps if you put your location in your post).Then if you upgrade to a 200A main service in the future you already have everything for your shop in place.

 

[mrb]

since your garage is detached, you need to install two ground rods 6 feet apart at the garage, and you have to run four wires of course.

 

[Cuda]

since your garage is detached, you need to install two ground rods 6 feet apart at the garage, and you have to run four wires of course.

Not to derail the thread but you need to run a ground from the house as well as two grounds 6 ft apart at the garage?

 

[mrb]

Not to derail the thread but you need to run a ground from the house as well as two grounds 6 ft apart at the garage?

yes. this is very important. they each serve different purposes

 

[Cuda]

So are these grounds all connected together at the sub panel?

 

[mrb]

So are these grounds all connected together at the sub panel?

at the subpanel you have a neutral bar and a seperate ground bar. The neutral bar is NOT connected to the can (box). The ground bar is. The ground from your feeder, the grounds from your branch circuits, and your grounding electrode conductors go to this ground bar.

 

[Cuda]

ok. Thanks for the help. I didn't know grounding rods were required at the garage panel if you were running one form the house panel.

 

[mrb]

ok. Thanks for the help. I didn't know grounding rods were required at the garage panel if you were running one form the house panel.

yes. have to do both. they serve different functions and cant do just one or the other