I am going to have new power service run to my detached garage from the house. I have 200 AMP service running into the house and have plenty of room for more breakers. I have a workshop in the garage and have power tools that draw 15-20 AMPS (one at a time). Should I put in 100 AMP service (panel) in the garage or something less?

 

If you want to run the hefty cable for 100 amp, and can connect it into the main, go for it.. 60 amp could be an option..

 

The size panel is one consideration. However, the panel can be larger than the breaker in the main panel.

I recommend a 100 amp sub panel in the garage. However, you don;t have to feed this with 100 amps. Feed it with 60 amps, if you think that is enough.

However, I also recommend feeding with individual conductors in conduit so that you can change the feed later if you need to upgrade.

 

> I also recommend feeding with individual conductors in conduit so that
> you can change the feed later if you need to upgrade.

Corollary recommendation: run conduit large enough to hold the largest conductors that you might want to use.