questions about adding 240V circuit to a garage

[BTL-A4]

I would like to add a 240V/50A circuit to my garage for a milling machine (currently 23A on 110), table saw (currently 15A on 110) and a welder. I thought I would have a NEMA 6-15 duplex plug for the mill and TS since they can use the same type of plug. The welder will need it's own outlet since it uses a different style plug (NEMA 6-50).

I think I'm leaning toward a sub-panel. I'm having solar panels installed later and they need at least one breaker, maybe 2. I think I only have 2 spaces left, but how do I tell? Can I add a subpanel without taking any space from the breakers? I think the subpanel will also allow me to add a car charger at a later date. I was thinking I'd add enough breakers to the subpanel to accommodate this. Am I on the right track? I'm getting quotes from electricians this week and want to be able to tell them what I want.

Additionally, I'd like to add 3 more 110V circuits to the garage. I currently have everything on just 2 circuits (there was ONE outlet in the garage when I moved in!). The TS trips the breakers if I use it hard and I think it would be better from a safety standpoint to spread out the loads, even though I don't use more than one or two tools at a time. For example, I use a vacuum with the planer. Would adding more circuits require another subpanel, or could I have just one subpanel?

Thanks!

 

[dave*99]

Post a photo of the existing panel with the cover off.
Is the main in good condition? Is it in need of replacement?
Will the sub panel be located next to the main panel?
The usual scenario is to evaluate all the loads in place and anticipated, then select the proper size sub panel.
If the main panel is full you can either move some circuits to the new subpanel or install tandem breakers in the main to free up some space----- assuming your main panel accepts tandem breakers.

 

[u2slow]

For the effort, I say use 6-20R and #12 wire.

If your welder is small enough, it may hold fine on a 6-20R circuit. (My MM211 does). You can buy or build an adapter cord.

 

[BTL-A4]

I've had a few electricians over to give me quotes. The main panel is fine. The sub panel will be located away from the main panel on a column in the garage. 3-4 turns to run conduit , about 40 feet or so. They all said I could "double up" the breakers. It looks like I will need to run a 50A or higher circuit to the subpanel, then have 3 lines coming off of that: a single, 240V, 50A plug for the welder, double 240V, 30A plugs for the TS and mill, and a 120V, 30A, 4-plug outlet for the misc items that still need 120. I don't use more than one machine at a time.

 

[Aaron_W]

I've had a few electricians over to give me quotes. The main panel is fine. The sub panel will be located away from the main panel on a column in the garage. 3-4 turns to run conduit , about 40 feet or so. They all said I could "double up" the breakers. It looks like I will need to run a 50A or higher circuit to the subpanel, then have 3 lines coming off of that: a single, 240V, 50A plug for the welder, double 240V, 30A plugs for the TS and mill, and a 120V, 30A, 4-plug outlet for the misc items that still need 120. I don't use more than one machine at a time.

My main panel was full. It is an older house so only 150A. I had a 60A subpanel put in, it is only about 20 feet from the main panel (both in the basement), they just moved a couple of breakers for stuff in the basement (water heater and a lighting circuit) to the new subpanel to make room for the 240v, 60A breaker in the main panel. I ran two 240v 30A, circuits for my mill and lathe, and a 40A for my welder. Later I ran some additional 120v 20A circuits.

All the 120v circuits are "doubles", 2 thin breakers that take the space of a single standard size breaker.

Only thing I would have done different is to have run the 240v 30A circuits as 20A which can have duplex outlets, larger than 20A have to be singles.
The current machines on 240v are well under 20A (mill draws 7A, the lathe 10A) and with the space I have it is unlikely I'll ever put a machine in the shop that needs more than a 240v 20A circuit. Duplex outlets would have given me more flexibility to run additional small machines on 240v without swapping plugs. It is a pretty minor regret.

All the breakers add up to way more than the incoming service can provide, but there is no situation where everything would ever be on at the same time.