Need power in my garage - suggestions

**dbhost** · 08-07-2009, 09:53 AM

If you have enough capacity left in your main panel, have your electrician, or you if you are competent in that area, install a breaker for a sub panel labelled something silly like, "Garage Sub". Run your circuits off of that.

My panel doesn't have the space or amp capacity left for what I need, I talked with the electrician and am having a new main box put in between the existing main panel and the meter, having the service at the meter upgraded to 200 amp, and pulling 80 amps to the shop. I intend to have a single 20 amp 220V, and 3 20 amp 110 circuits. 1 for dust collection, and 2 for everything else except lighting, which stays on the existing main. (No worries there).

A sub panel will help eliminate all those expensive, and potentially trouble prone wire pulls all the way across the house for each circuit... And give you more flexibility in the garage for later upgrades or reconfiguration.

**pelligrini** · 08-07-2009, 09:59 AM

Running a new line for the subpanel would be best. If you have a utility room nearby you could get some power off the dryer circuit, especially if you have a gas dryer.

Pulling anything off of the AC circuit nearby would probably cause some big problems. Having both motors starting at once would not be good. Doing a cut and having the AC kick on wouldn't be good either.

I used the 220 slot that went to my dryer on my main panel for the subpanel I put in my shop since we had a gas dryer.

If you can live with the conduit it would be easiest to do. Sometimes it can get in the way if you decide to hang shelves & cabinets later. There were a couple recent threads on the number of circuits and amperages a lot of us use. One was in crocket's shop threads, http://www.bt3central.com/showthread.php?t=46620.

You could probably run your lighting on the existing lighting circuit using the same switch. Probably ought to do some load calcs to verify.

**Garasaki** · 08-07-2009, 10:02 AM

I'd suggest adding as many outlets as you can. Believe me, you can never have too many.

Personally, in your case, I'd use wiremold which mounts to the wall surface and has different configurations for providing outlets and such.

On the other hand, I'm currently adding 2 circuits to my garage using pvc conduit and boxes (surface mounted). Honestly I haven't really researched the code about wether that's appropriate or not. The reason I'm going this route is that it's cost effective (only $1.50 for 10 feet of it) and I don't want to try to fish thru my ceiling space. It's easy to work with. But I only am providing a single outlet for each circuit (dedicated circuits) and I have tons of general use outlets elsewhere in the garage.

**LCHIEN** · 08-07-2009, 10:03 AM

if you have 40A circuits they will probably be for specific appliances, e.g. air conditioning, heat or water heater, stove, oven, etc. You cannot piggyback off of those, they require a dedicated breaker.

You will need an additional breaker for your sub panel so some empty breaker slots are needed.

My garage is unfinished (no sheetrock, bare studs) so I was able to run wiring stapled to the studs. I put in 4 additional 20A circuits which allowed me to have one for the Main tool (Table saw or whatever), one for the 120V DC, and one mainly for an air compressor, and one for whatever else was on, radio, chargers, spot lighting, small electrical tools etc.

For the ones destined to run one item, a limited number of outlets was put on the branch. For the general ones, more outlets were added. I numbered the outlet faces with the circuit breaker slot that drove it.

I located the TS outlet overhead which has its pluses and minuses.

**LarryG** · 08-07-2009, 10:09 AM

+1 on the suggestions to put in a subpanel, with a home run back to the main.

You don't want to "piggy-back" onto the A/C circuit. That system may require 40A all by itself; but even if it doesn't, the additional load of a starting motor (table saw or whatever) could overload the circuit and yield a lot of nuisance breaker-tripping.

You mention a "10A/220V circuit for the table saw." Did you mean 120V, which is what your BT needs? Or do you want a 240V circuit for a future, larger saw? If so it should be at least 20A, possibly even 30A (will depend on the HP rating of the motor).

There's nothing wrong with surface-mounting conduit and boxes; hiding everything inside the wall is not necessarily more "proper." In some respects surface-mounted conduit is preferable for a shop because if changing needs require you to rework your electrical, it's a lot easier to do with everything out in the open. Otherwise, it's mostly a matter of aesthetics. Some people don't like the look of exposed conduit, even in a utilitarian space like a shop or garage. Also, the exposed conduit and boxes can interfere with wall cabinets and such. But, from a standpoint of whether the installation will meet code or cause more problems, there's absolutely nothing wrong with surface-mount.

**jkristia** · 08-07-2009, 10:17 AM

hmmm - maybe I should talk to an electrician before I plan anything.

**jkristia** · 08-07-2009, 10:19 AM

>>You mention a "10A/220V circuit for the table saw." Did you mean 120V

I sold the BT yesterday and am waiting to receive my SawStop contractors saw which can be wired for 220V, but you are right, I should probably go with 20A/220, that should provide enough power for saw and future DC. But it all depends on whether I have that capacity in my main panel. I will have to wait and see.

**Uncle Cracker** · 08-07-2009, 10:36 AM

Don't forget that other tools that you may want to add or upgrade to might require 220V (such as a compressor or big dust collector). Think about what your ultimate build-out might be, and make allowances in your wiring that will keep you from outgrowing what you're putting in now.

JR · 08-07-2009, 10:43 AM

Originally posted by jkristia

hmmm - maybe I should talk to an electrician before I plan anything.

You should absolutely talk to an electrician ASAP. As has been suggested, you will most likely need to install a sub-panel, which should be done by an electrician. He'll know what sort of mounting location is required and will be familiar with all the tricks necessary to get the wire from the main panel to the shop. He will also advise you on the requirement for wire size and circuit breaker size. It is frequently commented that an elctrician may balk at installing just the sub-panel. They're notoriously unhappy about supporiting cheap homeowners. YMMV.

The remainder of your plan looks ok. Surface-mounted conduit is just fine. Alternatively, you could use MC cable, which is sort of like flex conduit and cable in one package. As LarryG mentioned, this is a matter of esthetics.

One final thought. You should plan for a dedicated circuit for a dust collector. You will eventually get one!

JR

edit: I have no idea how the "caution" sign ended up in the title bar. Disregard.

**poolhound** · 08-07-2009, 10:59 AM

Originally posted by jkristia

>>You mention a "10A/220V circuit for the table saw." Did you mean 120V

I sold the BT yesterday and am waiting to receive my SawStop contractors saw which can be wired for 220V, but you are right, I should probably go with 20A/220, that should provide enough power for saw and future DC. But it all depends on whether I have that capacity in my main panel. I will have to wait and see.

You also need to plan for things running together and although they may be on separate circuits of the sub panel the main breaker needs to be rated appropriatley. for example a Table saw 20A and good DC 15A can use 35A between them. You will also have lots of smaller stuff, lights, radio, fridge, possibly air filter etc. Also is does your space have heat/AC and where does that run from?

Bottom line is once you have planned a rewire get as much as makes sense as once you have the electrician there its the same cost to have him run cable and wire in a 60A circuit as a 40A one (parts & wire aside).

JR · 08-07-2009, 11:03 AM

Oh, one more thing. While you have everything torn down, paint the shop white! You probably already planned to do this, but I didn't see it mentioned in your OP. It will make a really big difference in how effective your lighting is.

JR

**jkristia** · 08-07-2009, 11:23 AM

so this turns out to be a bit complicated, but yes, I will get an estimate from an electrician for a new sub panel - until then I dont even know if I have enough power in the house. so ...

And yes, I am planning on painting the garage white.

Thanks for your suggestions

Jesper

**dbhost** · 08-07-2009, 11:30 AM

Sounds like you are on the right track... Consult with a GOOD electrician. Not a rip off artist. (Ask your friends and neighbors who they have used and are happy with).

**poolhound** · 08-07-2009, 11:31 AM

There are a few things that should be thought through (as you can see from folks comments) but its not that complicated once you get to it. With electrics being so integral to a shop its easy to make a hasty decsion about number of outlets, position and capacity and its a royal PITA to change later hence most folks input to think about things before you start running wire.

Unless you plan on turning every appliance, light and electrical item in your home on at the same time I would bet you have enough power in your house to add a sub for a small garage shop.

Originally posted by jkristia

so this turns out to be a bit complicated, but yes, I will get an estimate from an electrician for a new sub panel - until then I dont even know if I have enough power in the house. so ...

And yes, I am planning on painting the garage white.

Thanks for your suggestions

Jesper

Need power in my garage - suggestions

Need power in my garage - suggestions

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