110v vs 220v (how to wire my new Unisaw)?

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Forum topic by Fallon posted 11-08-2009 07:15 PM 10922 views 0 times favorited 14 replies Add to Favorites Watch
View Fallon's profile


90 posts in 3155 days

11-08-2009 07:15 PM

Topic tags/keywords: question

Just picked up my new 20ish year old 3hp Unisaw

Right now I have 2 20@ 110v outlets I’ve personally wired into my garage (came with 1 GFCI & 1 non-GFCI outlet when we bought the house new). I’m planning on adding a couple more 20@ 110v lines, or at least extending one of the current ones further down the garage. I’m also planning on getting a welder as my next tool purchase, which has a 70% chance of requiring 220v & will necessitate a 220v outlet.

I’ve already wired up my 220v hot tub & am more than handy enough to wire up whatever I need in my garage, it’s just going to be a few bucks for wire & other supplies. I’m tight on circuit breaker space, but can put in some piggy back breakers & get the job done.

Should I wire up my Unisaw as 110v or 220v?

The should both develop the same exact power, 110v will just pull twice the amperage. I’ve heard some people saying 220v runs smoother, but am not sure if that’s actually the case.

Should I just bite the bullet and wire up a 220v outlet for the saw now and whatever other equipment might use it down the road, or will 110v be just as good?

14 replies so far

View mikedddd's profile


147 posts in 3257 days

#1 posted 11-08-2009 07:50 PM

I could be wrong but I don’t think you can run a 3hp motor on 110v, I believe it will require a 20amp 220v service. If you don’t have much room left in your panel you might want to think about running a 40amp or 60amp service to a subpanel then you would have room for any future tools like a dust collector and such. Just a thought.

-- Mike

View GaryK's profile


10262 posts in 4016 days

#2 posted 11-08-2009 08:01 PM

If you can do the wiring yourself then I would go ahead and use 220. You could wire an extra plug to the same breaker for your welder and other things since I doubt that you will be welding and using the table saw at the same time.

I’m not even sure that my Unisaw has the option to run it at 110.

-- Gary - Never pass up the opportunity to make a mistake look like you planned it that way - Tyler, TX

View doyoulikegumwood's profile


384 posts in 4020 days

#3 posted 11-08-2009 08:21 PM

the 3 hp delta motor can’t be wired for 110 youll have to run a 220 for it but it will run very smooth and have more power then you can use.

-- I buy tools so i can make more money,so ican buy more tools so I can work more, to make more money, so I can buy more tool, so I can work more

View Cosmicsniper's profile


2202 posts in 3186 days

#4 posted 11-08-2009 08:25 PM

I agree. The 3HP Unisaw will likely need 220v. The motor is rated for 230v at 12.4 amps. I don’t think the Unisaw circuitry and wiring is beefy enough for a +25 amp draw at 110v.

-- jay,

View drfixit's profile


318 posts in 3171 days

#5 posted 11-08-2009 11:10 PM

Ive been thinking about wiring my Ridgid to 220 also, so after reading your post I decided to get off my rump and go for it. My saw seems to run much much better on the 220 now, comes up to speed alot faster and seems to run smoother. So I say go for it… now wishing I had done mine sooner.

-- I GIVE UP!!!! I've cut this @!&*!% board 3 times.... its still too short!

View Fallon's profile


90 posts in 3155 days

#6 posted 11-09-2009 12:18 AM

Humm… According to the manual at a 3hp Unisaw can run either. Not my exact model, but close

My only real problem with 220v is it’s going to take me a couple days to acquire the materials & spare time to actually run the wire. Ah well, don’t have anything I need cut on the saw in the near future anyway. ;-)

Off to Lowes I go.

View BlankMan's profile


1490 posts in 3381 days

#7 posted 11-09-2009 02:41 AM

When I got my Unisaw (it was and is wired for 220V) I was curious as to how many amps it really drew. So I checked it with a clamp-on ammeter and idling away it was around 3A (Baldor motor, not sure what they’re using these days). Cutting some red oak it jumped up to maybe 4A. Tried some other woods and it never got close to the 12 or 13A rating, don’t think it got past 6A. So at 110V you’d be pulling 6 to 8A, maybe a bit more, but fine for a 20A circuit. So if it is wired for 110V you could probably use it just fine until you get the 220 installed. But if you want to keep it at 110v and put it on a 25 or 30A breaker you have to change the outlet and it’s plug. I just looked into that myself because I was considering putting in a 30A 110V circuit for my air compressor and after I looked at the outlet and plug I’d have to use decided not to go that route.

Running at 220V it will come up to speed faster, that’s about all you’ll notice. They’ll be less losses in the wiring due to the wire’s resistance but that’s pretty much negligible,

-- -Curt, Milwaukee, WI

View doyoulikegumwood's profile


384 posts in 4020 days

#8 posted 11-09-2009 03:22 AM

fallon maybe i should have been clearer if you have a delta motor its 220 only if its the baldor motor you can wire it up for 110 or 220 the best way to find out is look at the plate on the side of the motor it will tell you if it is rated for both or not.

-- I buy tools so i can make more money,so ican buy more tools so I can work more, to make more money, so I can buy more tool, so I can work more

View Fallon's profile


90 posts in 3155 days

#9 posted 11-09-2009 04:22 AM

Plate says 220, so guess that’s the way it’s going to be. Will need the 220 most likely anyway if I end up building my own wheel frame to move the saw around with my friends welder.

View Cosmicsniper's profile


2202 posts in 3186 days

#10 posted 11-09-2009 04:46 AM

The problem with that user manual is that it covers all the Unisaws, not necessarily the 3hp version. So, it shows you what to do depending on which motor you got.

The volt and amp rating are usually straight forward on most machines. Some will say 110/220 while others might even say 220/440. In those cases, the hardware is capable of running at those amperages. But when the placard on the Unisaw says 230v at 12.4a, I see very little room for interpretation. Wiring it for 110 will push a lots of current, which means a lot of heat. If the Unisaw works on 110v, then I bet it wouldn’t work for long, especially if you cut a while bunch of hardwood at one time. Single cuts on even 8/4 maple wouldn’t cause too much problems or pull much amperage, but doing it all day would really warm things up.

Not telling you what to do, but just what I would do.

-- jay,

View cedarmannan's profile


5 posts in 2037 days

#11 posted 11-24-2012 04:59 PM

I just got a 1963 unisaw and i have yet to power it up. the guy i got it from said it is wired for 220v single phase. i took the switch cover off and see a green white and black wire. which i associate with 120v. i can’t easily get to the J-box on the motor to see what wires go to what in there, but i know that coming from the motor to the switch is green white and black. here are some pic’s of the plate on the motor. i can’t make out the 220v wiring vrs the 120v wiring…. any info would be supper great!!!

View toolie's profile


2134 posts in 2656 days

#12 posted 11-24-2012 05:08 PM

cedarmannan …...... it might be a good idea, in the future, to start a new thread rather than resurrect one that is over 3 years old. you might also try try old woodworking machines dot org:

-- there's a solution to every just have to be willing to find it.

View Loren's profile


10476 posts in 3675 days

#13 posted 11-24-2012 05:21 PM

It says to “Remove cover plate on front end bell”. You’ll
probably find something that matches the diagrams there.

View runswithscissors's profile


2768 posts in 2053 days

#14 posted 11-26-2012 05:37 AM

Almost every tool I have that can run on 110 or 220, I run with 220. Tool comes up to speed faster, and the power doesn’t fade under load. The lights don’t dim. Less heat build up too, I think. I have a Performax (not to be confused with the male enhancement nostrum) drum sander rated at 1 h.p., but only drawing 9 amps, I think. It’s always popping the overload button, even during a light cut. I am sorely tempted to adapt a 220v. 1 h.p. motor I have, even though I’d have to run 2 wires, as the conveyor feed motor would still require 110. I also make up extension cords out of 12-2 + ground, which prove to be very handy when I need to move tools around. No need for a neutral, unless you will be running a 110 item off the same line, as on an electric range, for example. Used to be, when you used B W and Gr wiring, you were supposed to paint the ends of the white wire red or black, so they wouldn’t be confused with the neutral. I get the impression this isn’t required anymore. (comment from someone who knows more than I do about it?)
I wish so many people were’t timid about putting 220 into their shops. It’s easy to install, and makes everything go better. I have my planer/jointer combo on one circuit with my welder and bandsaw (not running at the same time of course), plus a separate 220v. circuit for the DC. I also put in an outdoor 220 outlet, with its own GFCI circuit breaker. I run a chipper-shredder off that with a big 3 hp. Baldor motor that replaced a non-functioning ancient Tecumseh gas engine. Works great—no problems. Yet. Don’t use it in the rain, though.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

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