Unisaw on 110v.

[Michael Bullard]

Ok, here's the question -- Does anybody have any experience running an old unisaw on 110v? The motor can be wired for either 110 or 220. Unfortunately, I do not currently have 220 power available, and need to get cracking on things. I know that theoreticaly it should work just fine. I just wanted to get some advice from anyone with actual real- world experience.

My motor is a single phase 2hp, and I'll have a 20 amp breaker. I'll be firing it up sometime tomorrow. Wish me luck.

[Paul Demetropoulos]

The problem you'll encounter running the Unisaw wired for 110 is voltage drop. The line from your panel needs to be as short as possible to try and avoid problems.

My Unisaw is about 15 years old but it's always been wired 220. But I used to encounter the problem on site with my RAS that can be wired for either voltage. At 110 and far from the panel the saw would bog down and smoke, wired 220 in the shop no problem.

It's the same thing that can happen with a circular saw using a really long extension cord.

[glenn bradley]

With appropriate wiring and connector components my saw performs the same at 110v or 220v.

[Chip Lindley]

IF....your Unisaw is on a 110v/20 amp circuit (with no other appliances connected/running)

....AND IF you use a heavy gauge cord, you should be fine. 10ga. cord would be indicated for a 110v/20a circuit. You will need all the help you can get on heavy cuts. GoodLuck! MerryChristmas!!

[Joe Mioux]

my old saw had a 2hp motor. it came wired for 110v. I ran it like that for about 1-2 years. The saw performed fine.

Later, I added some 220's and rewired the saw to 220.

joe

[Michael Bullard]

Excellent. Thanks gentlemen. I'm gonna give it a try. The outlet is far from the box, so I'm a little worried about that, but I will be using a real gnarly extension cord, so hopefully I won't have too much drop.

[Rick Lucrezi]

Michael, you should be fine. It is less energy efficient, 20 amp 110 would use 10 amp on the 220, the real killer is the start up. The motor draws most amps under start up. Otherwise your saw will work fine.

[Tom Veatch]

Michael,

I generally use a rule-of-thumb of 8-10 amps/HP for 120v motors so you could be running pretty close to the edge at full power on the 2HP motor. 2HP is right near the break point at which you really should be on 240v power. You can get a better look at how close you might be to the edge by checking the Full Load Amperage (FLA) that should be on the motor dataplate.

During startup, you'll pull pretty close to the Locked Rotor Amperage (LRA) for a very short time. That may or may not be shown on the dataplate. But that is for such a short duration that it shouldn't cause nuisance trips on a 20 amp circuit with a properly functioning breaker. Of course, that's assuming the saw is the only load on the circuit. If the circuit is feeding other loads as well as the saw, all bets are off.

If you do have a problem it will most likely show up as nuisance trips during sustained heavy cuts that load the saw to the point of slowing the blade RPM. That could increase the amperage draw above the breaker capacity long enough to cause the breaker to open. If that happens, your only realistic option short of running a new circuit (either 240v or a heavier 120v) is to reduce the load on the saw; lighter cuts, thinner blade, slower feed, etc.

Good luck.

[Sonny Edmonds]

Time to sub panel your shop.
Stop goofing off and put a proper power center in for your shop.
You are courting a lot of trouble for yourself.
A Friend of mine was running his saw in his basement shop on existing wiring and his wife plugged in another quartz work lamp on the other end and POOF!
Out went the lights. He's got spinning sharp steel near his fingers in pitch blackness. And the saw catches and kicks back. :eek:
He got a "boxers break" to his hand, and a valuable lesson about doing things right for shop tools.

Maybe this could help you, too? (http://home.earthlink.net/~pie/subpanel.htm) Sub-Panel YOUR shop. :)

[Michael Bullard]

Thanks everybody. The thing seems to be purring like a kitten. Well, a manly, ugly, table-saw kitten, with mean fangs and stuff. Not like a cutsy girly little kitten with a bow.
Anyhow. I was just about to attach the nice biesemeyer fence that came with it, when I noticed something funny. It was set up for a lefty. The rail was clearly set up to have the bulk of the fence on the Left side of the blade. Bummer. Looks like I've got some drilling ahead of me. Anybody got any great tips for setting up a BM fence on an old Unisaw?