Reversible single phase 3 wire motor?

[dwpelland]

I'm writing user docs for a control manufacturer. I have what is called a 120/240VAC single phase reversing control which has three output terminals. COM, DWN and UP. In my experience I've never seen a reversible single phase motor with only three wires. Of course, I'm the first to admit that maybe I haven't seen it ALL. I'm willing to bet, though that if there is such a thing someone here has seen it and could tell me in what kind of application I would find such a critter.

 

[Jraef]

There are all manner of single phase motors out there, so your mileage may vary, but this is a fairly common revising scheme. Externally, you swap red and blue, white always stays the same. 3 wires.

 

[hillbilly1]

There quite common in greenhouses that have motorized ridgevents and shade cloths. they are are a dual winding motor, one winding for forward, the other for reverse. Be carefull when having multiple motors connected though, as the winding that is not in use is also "hot" while the motor is running, it will cause the other motors to reverse if they are turned off at different times.

 

[maghazadeh]

There quite common in greenhouses that have motorized ridgevents and shade cloths. they are are a dual winding motor, one winding for forward, the other for reverse. Be carefull when having multiple motors connected though, as the winding that is not in use is also "hot" while the motor is running, it will cause the other motors to reverse if they are turned off at different times.

They are also commonly used in the roll up door, like in the warehouse.

 

[hillbilly1]

Usually the ones used for warehouse roll up doors are standard single phase motors with a contactor reversing the start or run winding, usually the greenhouse ones are very small hp motors with massive gear reduction. I looked on the web to see if I could post one, but did not find it quickly. The greenhouse ones do not have an external method that changes the internal wiring. they just have three leads out of the motor, common, forward and reverse.

 

[dwpelland]

Bingo!

Bingo!

Yeah, this is exactly what I'm looking for. Thanks Hillbilly and others. The little controllers I'm working on have just the three terminals - COM, UP and DN - I needed to cite at least one example of an applicaion that can use them. I tracked the greenhouse app down to a German company, Lock Drives so Iknow I can get more detailed info if I need it. I also found a US mfr who makes actuators for boiler controls and some companies who make linear actuators for windows and such that look promising. Well, I still don't know it ALL, but thanks to your help I know a little more.

 

[Open Neutral]

There are all manner of single phase motors out there, so your mileage may vary, but this is a fairly common revising scheme. Externally, you swap red and blue, white always stays the same. 3 wires.

I seem to recall ones where you power one side of the cap, or the other. IOW, in the upper drawing, alternately feed the blue or the black.

{But then, of all the things I've lost, I miss my mind the most.}