New switch for an old table saw

[Dave Zellers]

I have a 30+ year old Rockwell 34-410 contractors table saw. The switch is failing- sometimes it won't turn off until I cycle the switch 8 or 10 times.

I have it set to run on 220v. Can I install this switch on it? http://www.grizzly.com/products/110-220V-Paddle-On-Off-Switch/H8243
And if a future owner were to rewire it to run on 110v, would this switch still be ok?

And for bonus points: The SN on this saw is 81AO3209. Does that mean it was built in 1981?

[Wally Alexander]

Yes to both questions, but I wouldn't want to. I would prefer a magnetic switch. If your current switch is not magnetic, go for it. If it is I wouldn't want to lose that feature. Just my opinion, but I think they are safer.
Wally

[John Coloccia]

The switch looks fine. It's concerning to me that your old switch is failing in such a bad manner. It's possible that you may have killed it by switching to 220. The higher voltage is able to jump a larger air gap and requires faster contact separation. It sounds like the contacts are sticking to each other, probably because of arcing. It also means that you could have a high resistance junctions that can heat up and potentially do all sorts of bad things.

[Dave Zellers]

I would prefer a magnetic switch. If your current switch is not magnetic, go for it.
Wally
The current switch is a simple toggle switch. Could you point me to the kind of switch you are referring to?

[Dave Zellers]

The switch looks fine. It's concerning to me that your old switch is failing in such a bad manner. It's possible that you may have killed it by switching to 220. The higher voltage is able to jump a larger air gap and requires faster contact separation. It sounds like the contacts are sticking to each other, probably because of arcing. It also means that you could have a high resistance junctions that can heat up and potentially do all sorts of bad things.
I switched to 220 30 years ago when I bought the saw. One thing that concerns me is, could it turn itself on, since the switch is bad?

I'm definitely replacing the switch- I just need a little guidance buying the right one.

[John Coloccia]

I switched to 220 30 years ago when I bought the saw. One thing that concerns me is, could it turn itself on, since the switch is bad?

I'm definitely replacing the switch- I just need a little guidance buying the right one.

Sure it can. Without seeing it, there's no way of knowing if it's sticking shut because of arcing, or if there's something mechanically broken.

[Wally Alexander]

Here's a link to several. http://www.grizzly.com/products/category.aspx?key=275010 You'll have to match up your amperage and horsepower. This one seems to be the best match. http://www.grizzly.com/products/category.aspx?key=275010 . They are a bit pricey, and limits you to just one voltage. If you've been happy with just a toggle switch, the first one you looked at should be fine, I was just offering another option. Do not just replace it with a simple light switch, even if that's what's on there now, and even if it's a 220v rated switch. They are not rated for motors. (Though they are ok for some small motors, such as fans.)

[Dave Zellers]

Thanks everyone- helpful info. I think I'll go with the dual voltage switch. That way if I sell the saw and the new owner wires the motor back to 110v there won't be a problem.

Seems to be the simplest solution.

[Ron Natalie]

That grid paddle will work fine. It will run the motor at either voltage (it really doesn't give a hoot about voltage, just that it's AC and under 20A).

[Dave Zellers]

Do not just replace it with a simple light switch, even if that's what's on there now, and even if it's a 220v rated switch. They are not rated for motors. (Though they are ok for some small motors, such as fans.)

I sure didn't know this. What problems would they cause? I was just about to put one on my router table and I did put one on my old Craftsman vac years ago when the switch broke.

[John Coloccia]

I sure didn't know this. What problems would they cause? I was just about to put one on my router table and I did put one on my old Craftsman vac years ago when the switch broke.

For motors you typically want a switch rated for "motor loads". Any home center will have them, though if you can find a real electrical supplier that would be best. My local supplier doesn't carry them, but Home Depot does, if you can believe that.

It will disconnect the hot and the neutral at the same time (or both hot legs for a 240 system). In fact, I think it's one of the few times you're actually allowed to disconnect the neutral, as I understand it. Maybe an electrician can comment here. This effectively doubles the speed of the air gap when you flip the switch. Inductors (like motors) try to maintain constant current, so you need to break the connection very fast to prevent damaging arcing across the contacts. I should mention that there's a large in-rush as well when you first turn it on. Things like solenoids and other coils are even worse and can really do a number on a normal switch.

Anyhow, this is why I thought switching the TS switch to 220 contributed to it's demise. The speed at which you need to create the air gap is a function of the voltage in this case.

[Dave Zellers]

Wow. I sure didn't know that! Thanks.

Ordered my new dual volt saw switch yesterday plus the 110v one for my router table.