Electrical outlets in shop.

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Forum topic by woodworkingdrew posted 03-27-2014 04:07 PM 1686 views 0 times favorited 15 replies Add to Favorites Watch
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190 posts in 1608 days

03-27-2014 04:07 PM

So as I have expanded my work shop tools, I have noticed an increase of my breakers poping. My uncle who is an electrician ran 3 20 amp circuits to the garage for me. What’s the best way to divide them up? I have a table saw, jointer, (soon to be a planer too), air compressor, air filtration unit, and miter saw/router. Would you put any of these things on a plug/switch line or all just standard plugs. Thanks!

-- Andrew, California

15 replies so far

View Farrout's profile


185 posts in 3154 days

#1 posted 03-27-2014 04:35 PM

I would probably go with standard plugs. All your equipment has on/off switches. The frustration would come when you try to turn on the table saw at the local switch and nothing happens because you had the switch at the outlet off.
Could be a safety issue also, if you accidentally have the tool switch on then turn on the outlet switch.

-- If we learn from our mistakes, I should be a genius!

View Purrmaster's profile


915 posts in 2092 days

#2 posted 03-27-2014 04:36 PM

I apologize if this isn’t precisely what you wanted to know: The things that draw the most current and pop my breakers are my table saw, planer, and Shop Vac. I’d try to separate those on different circuits.

View Marcus's profile


1163 posts in 2019 days

#3 posted 03-27-2014 04:38 PM

I had one dedicated switch that was only for my dust collector which I had a wall switch on…made life just a bit easier. I actually duct taped the cord to the outlet to avoid “safety issues” as Farrout mentioned (didnt want anyone using that outlet for anything else).

View TechTeacher04's profile


383 posts in 1531 days

#4 posted 03-27-2014 04:40 PM

The key is to put high draw items like a planer, dust collector and table saw on separate circuits. Plugs that you might use for a sander or router could be on the table saw circuit because they will not be running at the same time. Dust collector and table saw or planer would be a bad idea because they will often be running at the same time.

A to your plug switch question I prefer plugs, personal preference. I have lights on switches that it. I like being able to isolate each tool by using the switch on the tool. I also have a 5 year old who know how switches work so it adds safety for my application. Many tools are unplugged for that reason.

View woodworkingdrew's profile


190 posts in 1608 days

#5 posted 03-27-2014 04:47 PM

I agree with the dedicated circuit for the high amp tools. I was planning on doing a duplex receptacle for the table saw/ Jointer/planer.

-- Andrew, California

View crank49's profile


4030 posts in 2970 days

#6 posted 03-27-2014 05:14 PM

For what it’s worth I’m wiring my shop right now.
I’m putting 3 circuits, (A,B, and C) for outlets for general use and all are 20 amp, duplex outlets in quad boxes.
Every Quad box has two supply circuits.
So if the left hand outlets are circuit A, then the right hand outlets are on circuit B. Or B and C, or A and C, etc.
This way, if I plug the Jointer into one of these outlets, for instance, I know the other side will be on a different circuit,

View Purrmaster's profile


915 posts in 2092 days

#7 posted 03-27-2014 05:48 PM

I’ve got only two circuits in my shop (I’m sorry, I don’t know the amperage off the top of my head) and the overhead lights are also hooked up to them. I most often tripped the breakers when I was running my planer and my shop-vac (I don’t have a proper dust collection system) on the same circuit. Also, when I had a heater hooked up and used pretty much anything else on that circuit.

View Manitario's profile


2630 posts in 2882 days

#8 posted 03-27-2014 06:46 PM

Most of my machinery has dedicated circuits, mostly because they use a lot of power and are in separate places in my shop eg. my DC has its own 240V 30 amp circuit, planer has its own 240V 30 amp circuit etc. Other than that, each of my walls has 120V 20amp receptacles, with each wall having its own circuit. I don’t tend to run more than one tool at once eg. I’m not going to use my mitre saw and drill press at the same time, so I don’t have any problems with breakers popping. If you’re running a shop vac or a compressor on the same circuit at the same time as eg. a mitre saw then you will pop breakers.

-- Sometimes the creative process requires foul language. -- Charles Neil

View FellingStudio's profile


93 posts in 1682 days

#9 posted 03-27-2014 07:09 PM

It’s pretty simple in a wood shop … you can pretty much figure that any tool that will be running will be maxing out the circuit that it is on. So, any tools that will be running simultaneously should be on separate circuits. This means that the dust collector and compressor should be on a dedicated circuit, lighting should be a dedicated circuit, and every other tool can share another circuit (presuming they have the same voltage/ampacity requirements.)

-- Jesse Felling -

View MrRon's profile


4770 posts in 3243 days

#10 posted 03-27-2014 07:39 PM

In a small one man shop, you should have a minimum of 3 independent circuits, of 20 amps each If you have a 220 machine, that would be on a 4th circuit. The 110 V machines can share a common 20 amp circuit and the DC and air compressor can share it’s own 20 amp circuit. An A/C can add still another circuit. This is assuming you are not running more than one machine at a time, that would be highly unlikely. Make sure the panel you are coming off that feeds your shop circuits has enough amps. You really have to take into account power used by the house, like water heater, A/C, refrigerator, washer/dryers, etc.

View Don Butler's profile

Don Butler

1092 posts in 3395 days

#11 posted 03-27-2014 08:30 PM

May I just add one observation to the list of suggestions?

I noticed one mention of duct tape.

Its not commonly known, but duct tape (the silvery colored one) will actually conduct electricity.
It won’t carry a big jolt, but you can get a noticeable shock if one side is in contact with a bare wire or connecting screw.


-- No trees were damaged in posting this message, but thousands of electrons were seriously inconvenienced.

View bbc557ci's profile


595 posts in 2074 days

#12 posted 03-27-2014 08:41 PM

May I just add one observation to the list of suggestions?
I never would have thought of that, but then, don’t know if I’d use duct tape. Great info regardless!!

FWIW…. I have shop lights on their own circuit, and my HF dust collector on another circuit. And then run my planer and all other 110V tools on 3rd separate circuit. TS is a Unisaw 220V so of course, it has a separate circuit.

DC draws allot of amps so it should be on its own. The rest I figure I’ll only be running one at a time so I just keep them off the DC circuit. Another FWIW all 110V wiring is 12 ga. and 20Amp breakers.

-- Bill, central where near the "big apple"

View Purrmaster's profile


915 posts in 2092 days

#13 posted 03-27-2014 11:20 PM

Good to know about the duct tape. I figured it would actually be insulating. Good thing I’ve stuck to electrical tape so far for wires.

View Marcus's profile


1163 posts in 2019 days

#14 posted 03-28-2014 12:42 AM

I didnt know that about duct tape, but I’ll consider that an extra security feature. If someone seeing the duct tape on the cord still wants to unplug it for their own use, maybe a bit of a shock will be a deterrent.


View Picklehead's profile


1041 posts in 1929 days

#15 posted 03-28-2014 01:53 AM

In my shop, the 4-banger receptacle boxes have the left side on one breaker, the right side on another breaker, spread around the room every 5 feet or so. 20 amp breakers, plug one thing in left, one thing in right side. Never busted a breaker. DC is on its own breaker in the corner.

-- You've got to be smarter than the tree.

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