three phase motots

[samreen]

what is the criteria of selecting 3 phase motor over 1 phase?

 

[Skogsgurra]

Power range. Starting torque. Availability. Price.

If more than one or two kW, three phase is usually preferred. Starting torque for a single phase motor is usually low, fans need low starting torque. Single phase motors are not available for high kW applications. Price starts getting high in comparison when kW gets above a few kW.


Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[itsmoked]

3phase are about 3 times more reliable.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Eclair]

And what about the choice between a 120V 3-phase or a 600V 3-phase for the same power.

Don't considerate the transformer availability or the size of the cable in your answer.

 

[davidbeach]

120V 3-phase is extremely rare, 600V 3-phase is mostly Canadian. 208V 3-phase (200V motors) and 480V 3-phase (460V motors) are far more common in the US.

 

[Adamito]

As long as I know, you should choose the higher voltage available on site. This is simply a matter of decreasing the current in the motor, meaning smaller and cheaper wires.

Adam
Engineer-in-Training