Old single phase motor hookup?

[WobblyHand]

Hmm, I'm going to take apart the motor again. Maybe I was looking at a centrifugal switch but didn't realize it. Just looked up what they look like. Could be the switch is bad, or the cap is too small and the motor never gets up high enough speed to trip the switch. The motor is rated as 1725 RPM, so the trip point would be above 1500 RPM.

 

[WobblyHand]

Typically the two windings are wired in parallel. Swapping the relationship of the two windings should change directions.

T1-T2-Line1
T3-T4-Line2

if direction is wrong swap T2 & T4.

Ok. Thanks. I'll try it. Worst case the breaker blows! Maybe I will hear the centrifugal switch this time...

 

[CluelessNewB]

A split phase motor would still have a centrifugal switch.

 

[benmychree]

Whether a cap start or split phase, I'd think it would still need a starting switch.

 

[silence dogood]

I did some research on this motor. It is called a permanent capacitor induction motor. I does not need a centrifugal start switch. The capacitor should be the right size. Too big and you will burn up the start winding. Here are the good points, when it gets up to speed, the speed is constant. It's reversible, I think by reversing one of the windings. It has pretty good torque when up to speed and very efficient. Bad point. Low starting torque. Try thoroughly cleaning it out and relube. Hope that helps

 

[WobblyHand]

A split phase motor would still have a centrifugal switch.

My motor does have this switch. (I didn't recognize it when I saw it the first time.) I removed the capacitor and wired it the way you said. Started right up! Ran it a while just to see if anything was getting warm. Nope, it ran pretty cool for 5 minutes. When it spun down I heard the switch click. The low value cap was restricting the current in the coil. This is awesome! Thanks so much!

Now to see if I can clock the gear head so the output shaft is facing vertically. I'd like to make a slow speed grinder out of this.

 

[WobblyHand]

I did some research on this motor. It is called a permanent capacitor induction motor. I does not need a centrifugal start switch. The capacitor should be the right size. Too big and you will burn up the start winding. Here are the good points, when it gets up to speed, the speed is constant. It's reversible, I think by reversing one of the windings. It has pretty good torque when up to speed and very efficient. Bad point. Low starting torque. Try thoroughly cleaning it out and relube. Hope that helps

This motor has a start switch. Just didn't recognize it when it was apart. But when I wired it without the cap it started right up instantly. I could hear the centrifugal switch close when the motor was winding down. Now that I know it works, I'll clean it up. There's a lot of grime and grit on the outside.

Start winding and run winding have essentially identical resistance. There's really nothing to differentiate them from one another.

 

[markba633csi]

That's one of the smallest split-phase motors I have seen. Most of the ones that size are permanent split cap (capacitor run) types, with no internal switch. Or shaded pole
-Mark

 

[silence dogood]

That's one of the smallest split-phase motors I have seen. Most of the ones that size are permanent split cap (capacitor run) types, with no internal switch.
-Mark

I agree with you Mark, That motor was a real head scratcher. Even though I suggested it, did not think a motor that small would have a centrifugal switch. Well, I learned something new today.

 

[WobblyHand]

Not obvious how to clock this thing. The wiring is fixed to the case, which now that I write this, seems obvious. The back of the motor has two cut outs (at 90 degrees) for wiring to feed through. But, the other location would make the oil cup upside down when the shaft is up. No good. There doesn't seem to be an obvious way to separate the motor from the bell housing of the gear reduction. No little slot to cam the pieces apart, like the back cover has. Worst comes to worst, I could make another notch. Going to sleep on that.

Seems one of the long screws holding the case to the bell housing has some damaged threads, right at the tip. This is a 4" 8-36 screw. I cleaned up the threads with a file. I had to get my thread gauge and look at it. Nothing "normal" seemed to fit. Yep, a slotted round head screw, 4 inches long at 8-36. Is there a reason to use the fine pitch? Is it stronger?