Quad 20A 220 breaker vs 30 amp and changing cords.

[Tony Gomez]

My panel is very limited. At the moment, I have 2 spaces open. I also have an un-used 30 amp 220V breaker that is for my electric dryer, but I use gas. My garage only has 15A @ 120v, but I want to add some 240V so I don't have to use the hack job with the dryer outlet adapter cable.

I have a few options and I'm not sure if all are legal and if one is best.

I have 3 240V pieces of equipment to consider.
Table Saw: G0715P "8A at 220V"
Jointer: G0568 "12A at 220V"
Dust collector: Unknown, but lets say 2HP, so G0548ZP to make it easy. "240V, single-phase, 9A"

1) Get a quad double poll common trip breaker (BQC220220) for the last tandem breaker spot. Use it to make 2x 240V @ 20 amp circuits. Use one for table saw or jointer and the other for the dust collector.
2) remove the 30A dryer breaker, cap of the wires, add full sized 20 A 240V breakers to make 2x circuits
3) Use the last 2 pole slot to add a 30 A breaker and do a multi gang outlet with 6-30 outlets to run the saw OR jointer AND DC at the same time one one circuit. this would require me to change the cords on the equipment to p6-30 plugs. I have a bunch of heavy duty 12 awg raw extension cord for this.

[Carl Kona]

What about adding a sub panel that will give you more expansion and versatility. I am in a similar situation and will adding a sub for all my basement needs. Taking your main size into account of course.

Carl

[Chris Hachet]

What about adding a sub panel that will give you more expansion and versatility. I am in a similar situation and will adding a sub for all my basement needs. Taking your main size into account of course.

Carl

This is exactly what I am going to do.

[Tony Gomez]

My house only has a 100 A service. Not a big house. I thought about a sub panel but decided against it because 1) I'll very likely not need more than what I listed in the future (I'll regret saying that later :P) 2) While I think I know the code for adding the outlets, I don't for the subpanel. 3) It's a fair bit more expensive when all is said and done 4) the garage has finished walls, so this would be a lot more work than just the outlets. The original plan was to just drop some outlets straight down below the panel. No wood to to through and only a little dry wall to get into for clamps at the panel and the outlets.

[Mike Ontko]

FWIW - my shop is in a finished garage space, and when faced with a similar decision three years ago I'd decided to go with the sub panel option. I have a friend who's a licensed electrician though, which made it much easier to make the decision...you're own mileage may vary depending on the contractors you could get bids from. I also cut away the lower 18 inches of drywall so the wires could be run inside the wall (6" studs) and then replaced, retaped, remudded, and repainted everything afterwards.

The service I created isn't huge (can they ever be big enough?), but in addition to several 110V 20A circuits, I've got one 220V 30A circuit dedicated to an electric heater, a 220V 20A circuit dedicated to my DC, and one remaining 220V 20A circuit that I share between my bandsaw and jointer, and eventually my tablesaw. It's only a hobby shop, so I don't mind swapping plugs out but it would certainly have been great to have more circuits available.

[Josh Kocher]

I wouldn't start opening walls or make sacrifices on receptacle locations.

I'd put a subpanel where your existing wiring comes in and then run conduit for my needs outside the wall.

Subpanels aren't expensive.
Conduit is cheap and easy to install.

You'll get everything you need where you want it now and simple modification/expansion if your needs change.

[George Werner]

Agreed with the other posters, even though you only have a 100A service, go with a small sub panel. They're cheap and will give you the most flexibility for the future if your equipment needs change.

[Julie Moriarty]

I agree, the sub panel is my first choice. If you're dead set on the receptacle option, you can place a 2 pole receptacle at the location of the each of the tools you mentioned. You can then run them off the 2P breaker the same way you'd run a string of receptacles off a 1P breaker. So long as the draw of the DC and the highest amperage tool combined doesn't exceed 80% of the breaker size, you should be good. I think I drew up something like that in the conduit tutorial I did. It's in the sticky section.

EDIT: The design thread is on the 2nd page of the conduit tutorial. Instead of two duplex receptacles, like what's shown on the drawing, just imagine they are 2P receptacles. Here's the link: http://www.sawmillcreek.org/showthre...orkshop-Layout