I can't give technical advice, but I put in a 20 amp double pole (220v) breaker for my 3hp jet tablesaw and am yet to have a hiccup. I only have 4 feet of 3 wire 10 gauge wire though. Just remember, it is safer and easier to go heavier up front to keep the wire from overheating. There will be some fellers with more electrical experience in shortly I'm sure.

 

I don't know about the Unisaw but the Saw Stop came with a 220 plug like the huge picture below. I actually thought that was strange because both the Grizzly and Shopfox saws had no plug.

220v 20 amp with #12 wire should be the recommended stuff. If it was me, and I did do this. I would run #10 just in case you upgrade to a 5 hp saw later. I ran 10-3 with a ground because i also back feed the house of the same outlet when storms knock out the power. I used the 30 amp 4 prong twist lock but that was what was needed for the generator.

If your running an extension cord 30 ft , I would use #10 wire but if possible run the permanent power.

 

I also run my 3hp Unisaw on a 20 amp circuit without any problems. My plug is identical to the one Rich shows above.

 

Would this be the outlet (NEMA 6-20R):

http://www.twacomm.com/catalog/model_5821.htm?sid=0AFDF9124B365DDAF65A165C96DCB5C4

I see no reason for a double outlet, since this will be dedicated to one tool.

 

what i'd do.....

Just incase you wanted to run a large planner or something with a bigger motor later Id run 10-3(with ground) and use a nema 14-30 plug. If the saw comes with a three prong plug cut it off. All motors should have a dedicated neutral and ground, as well at the "hot" requirement. Current electrical code in new home construction is a dedicated neutral on all double pole circuits, i.e. dryer, stove, heat pump, hot water heater. Its safe practice and just makes sense.

jraks

 

Just incase you wanted to run a large planner or something with a bigger motor later Id run 10-3(with ground) and use a nema 14-30 plug. If the saw comes with a three prong plug cut it off. All motors should have a dedicated neutral and ground, as well at the "hot" requirement. Current electrical code in new home construction is a dedicated neutral on all double pole circuits, i.e. dryer, stove, heat pump, hot water heater. Its safe practice and just makes sense.

jraks

This garage does not have room for any more large tools after the Unisaw since it is not dedicated to wood working. I can not think of any tool that would need the 4 prong dryer outlet. Right now I am looking at options to build my workshop, where I would put multiple 220 outlets. :yes:

 

thats not the point....

I think your missing the point mwhals. It doesnt matter if you have room for more tools or not. You should always wire 220--240 volts motors with a 4 wire conductor that meets or excedes the motor rating. If you use the 3 prong plug previously shown you will not have a dedicated neutral and thats not correct.

jraks

 

I think your missing the point mwhals. It doesnt matter if you have room for more tools or not. You should always wire 220--240 volts motors with a 4 wire conductor that meets or excedes the motor rating. If you use the 3 prong plug previously shown you will not have a dedicated neutral and thats not correct.

jraks

So, are you suggesting to put a new 4 wire cord on the saw? Where do you put the ground wire in the switch box?

 

The 4 wire 220V outlets are for providing 220/110 to machines that use both like a machine that uses 110 for a light. The 110 power comes from one hot and the neutral while the 220 power comes from the two hots. There is a ground in both cases. I have not seen a woodworking machine with 4 wires. All the ones I have seen had two hots and one ground. Same with the 220V air conditioner units.

This means the NEMA 6-20R (30R) would work for all the tools I would most likely have.

With that said, I realize there may be a tool the has 4 wires. What I could do is run 10-3 wire and use the 4 connector receptacles. I could then add a 4 wire plug to tools that do not have the neutral wire, which would just leave last connection on the plug empty. It is no different than plugging a two prong 110 plug into the 3 prong outlets in that the equipment has one less wire than the plug. The extra wire would just be unused, but that is no problem.

I will probably make an adapater that would have the 6-20R receptacle on one end and the 4 wire plug on the other. That way I don't void the unisaw warranty like I saw on some other threads I found in various forums (not sure if it is true though).

I will have a licensed electrician friend help with the wiring to make it legit since I would need it inspected anyway. He will know all the codes.

 

mwhals if your saw comes with the plug 3 prong as I showed above and confirmed by john his unisaw has the same one. You can run the 3 prong outlet I showed above. My Shop Fox Saw was wired with the 4 wire twist lock but I wired it according to the manual and it was an option. As I said earlier my Grizzly and Shop Fox saws did not come with plugs but my Saw Stop did and I bet the Powermatic and Unisaw both come with the plug.

 

I have decided in the garage to just wire it with the NEMA 6-20R, because WV doesn't have the 4 wire requirement and 220V single phase does not use a neutral.