Valve Actuators

Since it is such a small load there is little reason to make it more complex by going to 3 phase. Your 3 phase units if available will cost more and be a lot harder to find.

Guess it all depends on the *size* of the actuator ;-)

In some industrial settings, the actuator for a motor operated valve can be

5 hp. And if you already have some 3-phase MCC's around, putting in another cell for an MOV is no big deal. Three phase is, of course, easy to reverse and can be more compact.

daestrom

Motorized valve actuators are very common in water and wastewater treatment. Motor controls are generally integrated into the acutator, with either integral or separate local control and connections for remote/automatic control. I've seen them with both 120V single phase and 480V three phase power, even in fractional horsepower sizes. Single phase motors for these are designed for easy reversing, with two windings and three leads, Open, Close and Neutral, and the starting capacitor connected across the Open and Close leads. I had one plant where the valves on each filter were fed from one three- pole CB in a 480V loadcenter through a local disconnect switch and separate manual starter switches for each valve.

I wouldn't say that three phase units will be a lot harder to find. Limitorque and Rotork both list them as standard models, complete with digital control and network capabilities. The best reason I can think of for using the higher voltage is to reduce the load on the lighting transformer.

Mike

That's assuming you're not controlling the flow of water to a major city. But then, I'd expect such motors to be 480 volts and up.