# Electrical Question

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• posted on October 19, 2005, 10:15 pm

Recently moved into a new house. It has a detached one car garage. The house is not new and I am going to make the garage my work/woodshop.
The previous owner has a 20amp line run to the garage. Right now only powering a garage door opener, fluorescent shop light and a couple of outlets. What would I need to upgrade to run a decent woodshop?
So far the only things I will be powering are my table saw (Dewalt Portable saw), scroll saw, Dewalt DW735 planer and 6" Joiner . Soon to be adding a band saw (still determining what I want) a drill press (maybe) and some kind of dust collection/air filtration.
Anyone have ideas of what I could do?
Thanks,
Bill
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• posted on October 19, 2005, 10:21 pm

Lots more than one 20A circuit at 120V...

You'll want at least one 240V circuit, and several 120V circuits.

I'd run a 240V feeder at 60A to a subpanel in the garage, and separate branch circuits from the subpanel to wherever they're needed.
--
Regards,
Doug Miller (alphageek at milmac dot com)
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<%-name%>
• posted on October 19, 2005, 11:11 pm

The more the better. You could run a 100A subpanel in there and be prepared for just about anything. On the other hand I get by with a 20A 120V duplex receptacle and one 220V for the saw. I have kids around so I unplug tools when not in use.
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• posted on October 19, 2005, 11:35 pm
I know it sounds crazy, but you may not need any new lines.
If you will be operating only one machine at a time and all your equipment is 120 volt, you can calculate the need for additional lines.
Lights don't use much energy. Divide the total wattage of lights by 120 and that is your amperage for the lights.
Check out the amperage of the garage door opener and add this to the light amperage. (you only need to do this if the garage door will be used while a power tool is operating)
Check the amperage of the largest tool you have.
If you are still under 20 amps you are OK.
Good Luck.

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• posted on October 20, 2005, 12:22 am
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Every time you turn on the saw, the lights will dim! You should have a separate line for tools (best doing like other post suggest) Just my \$0.02 Frank
Tom H wrote:

</pre> <blockquote type="cite"> <pre wrap="">Recently moved into a new house. It has a detached one car garage. The house is not new and I am going to make the garage my work/woodshop.
The previous owner has a 20amp line run to the garage. Right now only powering a garage door opener, fluorescent shop light and a couple of outlets. What would I need to upgrade to run a decent woodshop?
So far the only things I will be powering are my table saw (Dewalt Portable saw), scroll saw, Dewalt DW735 planer and 6" Joiner . Soon to be adding a band saw (still determining what I want) a drill press (maybe) and some kind of dust collection/air filtration.
Anyone have ideas of what I could do?
Thanks,
Bill </pre> </blockquote> <pre wrap=""><!---->
</pre> </blockquote> </body> </html>
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<%-name%>
• posted on October 20, 2005, 12:47 am
First step is to find out the amperage of your utility supply line to the main panel.
Then work out what demands your household appliances are going to demand.
You said detached garage so install a subpanel for the garage. This is probably a job for an electrician.
Tomh may well be correct in that if your tools are not very high demand you may be able to run them one or two at a time on the small existing line.
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<%-name%>
• posted on October 20, 2005, 1:03 am
Tom H wrote:

All true stuff, but as someone who has a single 15A circuit, and the same beast of a planer as the OP, I would HIGHLY suggest you have your lights on a different circuit than your big tools. It is no fun having the lights go out with a piece of wood connecting you and a slowly spinning-down power tool somewhere in the darkness.
-John
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<%-name%>
• posted on October 20, 2005, 1:53 am
Seems like one of those situations where you can be penny wise and pound foolish.
You have the opportunity to set up a great shop for yourself. If you enjoy woodworking, a 220v table saw and a few other 220v stationery tools may well come into the picture sooner than you think. At a minimum you should install one decently sized 220v outlet and it probably won't cost all that much more to install a decent sub-panel as has been mentioned by others. If it were my garage and my house I'd get the sub-panel.
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• posted on October 20, 2005, 2:09 am

I have a 15A circuit, and if I run a bandsaw and a shop vac at the same time (acting as a duct collector) the circuit break trips.
At work, they have the labs set up so that every other outlet is a diferent circuit.
--
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<%-name%>
• posted on October 20, 2005, 2:48 am
here's a "seat of the pants, first look" thing to do:
go out there. turn on all of the lights and all of the machines that might self start- air compressor, AC, etc. then fire up your biggest machine and feed a thick piece of hardwood through it.
if the lights dim or you pop the breaker, you need to run more circuits.
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<%-name%>
• posted on October 20, 2005, 3:36 am
Read what John wrote (below) again, especially if you missed it the first time. After fighting sharing one outlet, two lights and a garage door opener with the rest of a 15A circuit that included the TV in the living room, we rewired the shop. We now have a 60A subpanel with 3 20A circuits, an A/C - it IS Houston, a spare 220 circuit, insulation and wallboard (I'd use ply for the walls next time).
The TV picture in the house no longer dims to half size when I use the RAS, the light (actually several of them now) doesn't dim, and I haven't tripped a breaker in 4 years. We're a 1man & 1 SWMBO shop specializing in custom miscuts, so only have at most two tools and a DC running at the same time, plus lights, maybe a fan, TV or radio and the A/C. Go with the subpanel. It shouldn't be \$ enough to be a deal breaker if you can handle the installation yourself.
You could pick up a Square D subpanel and a few breakers at the Borg for \$50-80. \$35 for the #12 wire, plus some boxes and 20A receptacles and staples, I'd be surprised if the materials ran over \$150 for a single car shop. Depending on where your main panel is (I was lucky, it was in the gara-shop already) getting the power to the shop could cost some bucks if you have to hire it done. Sure beats turning off the lights, the TV, unplugging the fridge, etc so I can fire up the RAS.
My 2 cents, back to lurking.
Regards, Roy

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• posted on October 20, 2005, 2:43 am

I built a lot of stuff in my garage/shop with nothing but a single 120v and stealing the dryer outlet for my welder. How many machines can one guy use at a time?
If I was adding, I would probably add big tho. Once you decide one circuit is not going to be enough you are pretty much forced into a sub panel. There is a legal way to run a 120/240v "single circuit" but why bother? For about the same labor and another \$100 in parts you can have all the power you want. It is hard to think 60a would not be plenty. Most amateurs seriously overestimate real load.
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<%-name%>
• posted on October 20, 2005, 3:11 am

Two. Any fair sized tool and a dust collector is overload.
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• posted on October 20, 2005, 1:28 pm
Edwin Pawlowski wrote:

Don't forget things like an air compressor or air conditioner or heater that may kick on and off by themselves.
-John
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• posted on October 20, 2005, 3:08 am

It sounds crazy because it is crazy.
I was able to run my benchtop saw with a single line like that. When I got a 1.5 hp saw and switched it on the first time, the lights went out for a couple of seconds. Scary. Next day I ran a new line.
He is getting a DC at some point. That and the saw or planer will trip the breaker.
--
Ed
http://pages.cthome.net/edhome/

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• posted on October 19, 2005, 11:42 pm

At an absolute minimum, run 30A, 240V, but if you can go at least to 60A. I have a detached shop and have been getting away with that for 3 years now. I often think about upgrading but as of yet, I haven't tripped the feeder breaker. I may get into trouble when I finally get around to putting in a DC.
-- Al Reid
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• posted on October 20, 2005, 2:06 am
I put in a 100 amp subpanel in my work shop feed by a 60 amp 220v breaker in the house. It is true that you will only use 1 machine at time assuming that only you are in the shop so you most likely will never need any more than 60amps 220V.
Add up the amps for all items that might possibley by run at the same time (Dust collector,Saw,Compressor,Lights,TV,Garage Opener,AC,Heater) and add 50% for future growth.
Remember each circuit should only be loaded to 80% max. 15amp = 12 amp max, 20 amp = 16 amp max so use a 100 amp panel with a lot of circuits and you will have a safe shop.
Do it right and you woun't be sorry later, overkill is a good thing when it comes to electricity.
Kevin

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• posted on October 20, 2005, 3:35 am
I would upgrade it to a 30 or 40 qmp breaker. You won't be pulling that many amps (since youcan only run one machine at a time, but you don't want to be popping circuits. If you have the ability or need you might want to run another 110 line there and give yourself 220.

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• posted on October 20, 2005, 4:41 am
wrote:

I sure hope you meant to say something other than what actually appears above. You can't simply throw a 30 or 40 amp breaker on a circuit wired for a 20 amp breaker. Likewise, the suggestion to simply run another 110 line to get 220 isn't what should be done. If he wants 220/240 in the garage, then he needs to run the proper 220 service out there. I just know you really meant to say something other than what you said above...
--

-Mike-
snipped-for-privacy@alltel.net
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• posted on October 20, 2005, 5:42 am
Put outlets where you need them. Even though #14 wire may be legal for 15A circuits where you are, use at least #12. Code in most places will allow 12 devices / circuit, but the guy who set that up must have been thinking of 60 & 100W light bulbs. If you go with the subpanel that most of the contributors have suggested, try to have dedicated circuits for your higher amperage tools, and for tools that may get stalled.
If you have to use extension cords, use #14 for tools under 10A, and #12 for tools over 10A, and keep the cords as short as possible (no coiling - increases resistance). Some people are going to say that the larger wire size is not necessary, but I am thinking of start up loads. My Father had a RAS, supposedly 12A, that kept blowing 15A fuses. He was using 100' of #16 cord to go 30'. I wired his shop with #12 and 15A rated outlets, & a 15A fuse. No more blown circuits. The larger wire size means less resistance, less heat, less overcurrent on the fuse, and less voltage drop to your tool.
Bruce Nelson