120V vs 240V for 22124

[Jay Radke]

Hi again,

I have the ability to run the saw at 240V if I so desire. I know 240V would give me the most out of the saw. Has anyone does this on this forum? If so what were the results and as always any hints will be welcomed.

Thanks,

Jay

[glenn bradley]

I asked this question back when I got my zipcode saw and the answer was (mostly) doesn't matter. The reduction in amperage and the move to a dedicated circuit may have something to do with folks saying they saw an improvement. The jury is still out for me on this as I plan my shop re-wire. I look forward to the other responses.

[scott spencer]

My 22124 is wired for 220v, and I did notice a difference in that the lights no longer dim, it has quicker startup, and it recovers quicker under heavy load. I noticed very little difference switching my former GI contractor saw to 220v on the same circuit...I'm guessing the 22124 has just enough additional draw that it taxes the circuit a bit more. It all depends on how adequate your 110v circuit is...in theory, 110v and 220v should be the same, but there tends to be more voltage drop in the 110 circuits as a whole. IMO, it's not worth investing in 220v if you're 110v circuit is sufficient, but if you've got 220v already available, I'd do it...there's no harm, possible gain, and the cost is a new plug to fit the 220v outlet.

[Jason Beam]

One factor in the decision to wire for 220 should be at least considered: You can't GFI protect 220 as far as I am aware. So, should your saw become energized, nothing will protect you from being zapped. And zapped good!

I now know why the old timers always used to say "Ahh, it's just 110". Both legs of 220 is a whole new experience!

[Rod Sheridan]

Actually, the 240 volt single phase service is only 120 volts to ground, identical to a 120 volt feed.

A GFCI device only protects people from a shock to ground, not from line to neutral, or line to line.

The shock hazard to ground from a tablesaw at 240 volts, or 120 volts is identical.


Regards, Rod.

[Jay Radke]

Either way I plan on putting a dedicated line in for the saw. Thats why I was wondering. Since I have to put in a line I figured that I would do it right the first time.

[Jason Beam]

Actually, the 240 volt single phase service is only 120 volts to ground, identical to a 120 volt feed.

A GFCI device only protects people from a shock to ground, not from line to neutral, or line to line.

The shock hazard to ground from a tablesaw at 240 volts, or 120 volts is identical.


Regards, Rod.

Thanks for clarifying that, Rod. I want to make sure I understand clearly, though. I didn't gather from your post that you CAN protect a 240 line with a GFI still, right?

So a 240 circuit cannot be GFI protected, however, the risk is still a 120v shock. The risk is still there, it's just not greater than that of a 120v line.

Is that right?

[Gary Muto]

Square D makes a 220V GFCI circuit breaker. I bought one for a hot tub about ten years ago ($120 for a 50 amp breaker:eek: ) I use it as a main to power my table saw and compressor subpanel.:p

[Alan Tolchinsky]

Thanks for clarifying that, Rod. I want to make sure I understand clearly, though. I didn't gather from your post that you CAN protect a 240 line with a GFI still, right?

So a 240 circuit cannot be GFI protected, however, the risk is still a 120v shock. The risk is still there, it's just not greater than that of a 120v line.

Is that right?

I understand there are 220 volt gfi outlets available but they're expensive. When I wired my shop the inspector checked the codes and said the 220's didn't need gfi protection. But all the other 110 circuits did.

[Don Bullock]

Either way I plan on putting a dedicated line in for the saw. Thats why I was wondering. Since I have to put in a line I figured that I would do it right the first time.

Jay, if you don't presently have a 220 circuit in your shop then this would be a good time to have one put in. I had one put in when I was buying my SawStop. More recently, when I looked at jointers, I wasn't limited to just a 110 machine. Having the 220 line opened up my possibilities in the shop. Because I already had the 220 I was able to get an 8" jointer instead of the 6".:D

[Rick Christopherson]

Either way I plan on putting a dedicated line in for the saw. Thats why I was wondering. Since I have to put in a line I figured that I would do it right the first time.Then your situation is the classic case of When NOT to Rewire the saw. If you are going to put in a dedicated circuit for the saw, then you will Not experience any gain by rewiring the saw to 240 volts.

What you would lose, is the ability to move the saw to another location or jobsite for whatever reason. You would also risk making a mistake in the rewire, and thereby smoke the motor in the process. This has happened, and this is the primary reason why I oppose rewiring motors for no reason.

On the other hand, once your new circuit is installed, if you were headstrong and still wanted to rewire the motor, then all you would need to do to change the house wiring to 240 volts is replace the breaker and the outlet. This can be done at any time down the road without having to pull new wire.

[Tom Veatch]

Either way I plan on putting a dedicated line in for the saw. Thats why I was wondering. Since I have to put in a line I figured that I would do it right the first time.

As others have said, your saw doesn't really care. It'll work as well on the 110 as it will on the 220. Other considerations may come into play however. You will draw twice as much amperage on 110 as you will on 220 with twice as much voltage drop/line losses which is probably the reason behind the light dimmings, etc. that others have mentioned. Depending on your situation, voltage drop may or may not be a significant consideration.

In my particular situation, choosing 220 for as many applications as possible made sense. But, my shop is at the end of about 200' of cable run (one way) from the main disconnect at the transformer. I don't remember the sizes used, but I ran a feeder that was the next size heavier than code and opted for 220 on every tool that allowed me to do so. The reason, to reduce the voltage drop to as low a value as practical.

It's worked very well for me, and rewiring the motors for 220 instead of 120 simply involved interchanging two wires in the motor's junction box. Based on my experiences, if you're going to install a dedicated circuit and if jobsite portability isn't important, I'd recommend going with the 220v. If portability is important and voltage drop isn't a consideration, stick with the 110. Your saw really doesn't care as long as the motor connections are set properly for whichever voltage you do use.

[scott spencer]

The rewiring of the motor is a task that takes just a few minutes, so is fairly easily reversible if need be.