Wally,
Have you looked for a wiring diagram on the inside of the cover you removed to get at the wires? I ‘m presuming that there isn’t a wiring diagram somewhere else on the outside of the motor. It is very rare for a large motor to not have a wiring diagram, but it is possible for the diagram to be missing or painted over on a used motor.
Are you wiring for 110 volts or 220 volts and, if the motor is used, are you sure the motor is a single phase?
John W.
Replies
Is this a Jet, or a Unisaw (Delta)?
FOr the Jet, the 3 HP motor is single phase, 230V only (no 115V).
BTW, the manual is at http://www.wmhtoolgroup.com/partfiles/M-708661.pdf; wiring diagram is on page 24. It shows the motor has two hots (black and white), and a ground (green).
Since you're wiring for 220V two-pole, there should be two "hot" wires and a ground.
Typical wiring code for single phase work indicates that hot wires should be black or red, neutral is white and ground is green or yellow with a green stripe (esp. europe).
I'm assuming you've run the wire from the panel with 110V on the black (hot), 110V on the white(hot), and the green remains ground. With a voltmeter you should get 110V from Black to Green, 110V from white to green, and 220V from black to white. If you aren't getting the above, you're wiring is off at the panel (wrong pole on the hot bus bar).
Since it's 220V, it doesn't matter which hot wire is which (unlike 3phase 575V). So you should be relatively safe hooking the black to the black, the red to the white, and the yellow to the green. This should give you the proper voltage and ground.
At this voltage, even an error won't hurt the machine. It's when you hook 220 to a 110V machine that things go bad. You'll know when the machine is one if it's right or not. If the motor doesn't run at speed right away, or doesn't start, etc. then the ground and a hot wire are mixed.
Of course, if they went all winky at the factory, all bets are off.
Best of luck.
black, white, and green..
Gee.. Singlr Phase 115 Volt if Green is the ground??
Sorry.. Motor plate should say Phase and Voltage someplace
Edited 4/22/2005 4:27 pm ET by Will George
Hi Wally,
A simple test meter is a very useful tool to have -especially when you are confronted by unfamiliar wires and colours. I would use the meter to at least determine which is the earth (ground) wire.
No doubt you have done the job by now, but with electricity it pays to check and double check, without guessing/experimenting.Sparkling eyes-no thanks!
If the motor doesn't have a wiring diagram, you might be able to find one for it on the manufacturer's web site. You can generally tell single phase from three phase because single phase needs starting capacitors, and three phase doesn't. If it's a used motor with no diagram and no surviving indication of make and model, I'd take it to a good motor repair shop. They may be able to recognize what it is, and check it out for you. Guessing wrong can fry what had been a usable motor.
-- J.S.
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