Hi guys a friend of my husbands gave me an old 5 horse electric motor single phase 220 volts. It has no wiring diagram with it. there are 4 wires (black) in a metal box mounted on the side of the motor. Two of the black wires have an extra band of tape on them. If I take an meter to one of the banded wires and one of the not banded wires I get a short and the same thing with the other two. So would I take both banded wires to one side of the 220 and the other two not banded wires to the other side of the 220 or do they go in series I don't want to burn it out before I get to use it Thanks Guys Nikki
4 wires, might mean dual voltage, 220-230 volts. Check each wire to the case. if any are "shorted" then throw the motor away. You should be able to read some ohmic value with the pairs of wires. not just shorted.
lastly you could try connecting the banded together and use the other two for the phases. No telling what will result, you might let the magic out. I made an suicide cord that I use for these opportunities. It has fuse holder in line that I can adjust for each situation.
I know this sounds like a throwaway answer but google every number on that motor plate. There is a good chance you will find a wiring diagram. Also poke around on the manufacturer's web site. There are a number of possible answers but you don't want to blow up your motor on a wrong guess before you look a little. My guess is it is the leads to the capacitor (taped) but that is just a wild assed guess. I also don't have a clue what the capacitor size might be. This probably hooks to a motor starter assembly, not just a switch. You may need one for overload protection among other things.
F Buy a 20 dollar ohm meter.... then check each bare lead to the frame of the motor..any read at all means the motor is shorted out..trash it.
if its not burned out, hook up the wires in various combinations and check the ohm reading between the two remaining bare leads... do this until you get the highest ohm reading. should be in the 4 to 7 ohm range.
Then supply those two leads with 220 volts. Have an amp meter clamped around one of the supply wires... it should read a few amps while sitting on the bench with no load, run smoothly and sound OK. Home depot has clamp around amp meters for 40 dollars.... Harbor freight has them for 20 dollars.
If that checks out OK the motor is probably fine. Attach it to your load... look in a motor catalog for the amperage a 5 hp single phase 220vac motor draws... my guess is that FLA (full load amps) not LRA...but FLA is in the 20 to 25 amp range at full load.
My wild guess on your application is that it will be half HP or less and the motor will run a lot less amperage...and thats fine.
If thats the case use #8 wire to power it, from a 30 amp breaker.
From your description I would say the 4 wires are the ends of 2 coils, a start and a run winding, They do this because single phase doesn't have the "chasing effect" that is required to start the motor from rest, so without that start winding the motor would just sit there and humm on the bench until you give the shaft a quick spin, then the motor would run up to full speed.
On some motors they switch out the start winding when the motor gets up to speed, you will hear a click of the centrifugal switch when you power up the motor also some motors they just leave the start winding in all the time.
Pick the pair with the lowest (Highest? anyone confirm?) resistance then add
220 volts and then give the shaft a quick spin in either direction, just keep your fingers out of the way.
Oh and P.S Make sure the damn thing is properly earthed for safety.
On Tue, 30 Nov 2004 14:29:51 -0500, Nikki put forth the notion that...
It's probably a reversible motor. One pair is your start windings, and the other is the run windings. I'd parallel both pairs and flip the switch. It's either going to start, trip a breaker, or make god-awful sounds, in which case you switch it off immediately. This shouldn't hurt it at all, as long as you don't allow it to do anything unnatural for more than a second or two.
You might want to look in the yellow pages for a motor shop. Big motors like that get fixed, not tossed so there are people who can tell you what you have and how to wire it. It is a shame to trash a good motor "smoke testing" it. Even in sleepy old Ft Myers Fla we have a couple places and those guys have already been good to me. Just be patient, they may be grumpy at first.
That sounds like an old repulsion-induction motor. These were used years ago because they give a good starting torque without drawing too much current. When the thing is starting pairs of those brushes are shorted and contact the commutator, causing it to start as a repulsion motor. After it is up to speed there as a mechanism inside the commutator that shorts out all the segments, causing it to run as an induction motor. Usually, there is also a mechanism to lift the 4 brushes you saw so they don't wear while the motor is running.
Take it to a motor shop for advice, a single phase motor like that will cost many hundreds of dollars to replace, even paying the shop 50 bucks to clean it up and mark the leads will be a good deal.
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