Synchronous motor starting issue

Hello,

I am trying to use some ball valves I bought, however some of the ball valves will not always turn when supplying the voltage. Other times it will. Does this mean it is bad? Or is there some circuitry I can add to fix the motor to always start.

When the motor doesn’t turn, it is just shaking.

The part I have is a TDY50.

In my research I found that it is a synchronous motor and that they have two windings and they have to becomes synchronized. So I was hoping I could add some circuitry to correct the starting issue.

Thank you,

Stephen

More information needed:

Those motors only need sufficient AC voltage to make them turn, as long as you are using a reasonable frequency (50Hz or 60Hz) they should work fine. However, what you can't control on them is the direction they rotate. You get a 50% chance of clockwise or anti-clockwise each time you turn them on so if your ball valve doesn't rotate continuously, you might just be driving it against the back-stop sometimes.

Unfortunately, with a two wire synchronous motor you can't easily control the direction it runs in. If you want to decide the direction you either have to use a motor with a phase winding or a reversible DC motor, in either case you wold still need a limit switch to turn them off when the valve has fully opened or closed.

Brian.

Single phase synchronous motors usually have low starting torque. It might be that the motor isn't suited for your application. Motors with run capacitor (two windings and three or four terminals) have higher torque and direction can be controlled.

I have never seen a ball valve driven by a single phase motor with arbitrary run direction.

Thank you all for the response.

I have taken the motor out of the enclosure to verify the functionality of the motor. I am applying a 120V to one lead and neutral to the other as per spec.

The motor acts the same way with the motor shaking. Some times the motor shakes for a bit then begins to spin.

I am not sure how the direction of this motor works, because I have never seen it mess up. There is no circuitry that would help in it either.

I agree that the motor direction is indeterministic, but it has always rotated in a CCW direction. Could it be this one has some phase windings to keep the direction.


However, I am still puzzled on why the motor just shakes and then begins to work sometimes other times it will shake for as long as I let it. I am using a standard wall plug so I don't see how the input voltage/frequency is an issue.


I didn't know if there was some extra electical components that help out a synchronous motor to not cause the shaking. I couldn't find anything online either.


-Stephen