415V 50 HZ Motors

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Artemis

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I need to circuit motors from India which require a 415V 50HZ source. My existing service is 277/480V 3 phase 4 wire. Do I need to go through the expense of a phase convertor or will these motors operate satisfactorily at the service voltage and frequency?
 
Artemis said:
I need to circuit motors from India which require a 415V 50HZ source. My existing service is 277/480V 3 phase 4 wire. Do I need to go through the expense of a phase convertor or will these motors operate satisfactorily at the service voltage and frequency?
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Depends entirely on your definition of satisfactory, and to some extend, what the motors are driving.

A lot of stuff coming from India these days. A lot of it is substandard as far as quality goes. The motor insulation might not like the output from a VFD. You can only find out by doing a little research on the motors.I would be inclined to start by asking the manufacturer of the motors.
 
Motors work properly by the application of a specific V/Hz ratio; 415V 50Hz is a ratio of 8.3V/Hz. But there is a tolerance of +-10% on the voltage to cover 380V systems, so typically they consider the design voltage tolerance to include 400V systems, making the acceptable V/Hz ratio 8.0 V/Hz. If you apply 480V 60Hz to it, the ratio is 8.0 V/Hz, so that is well within the tolerance of that motor. This means you will get full torque from that motor without saturation; i.e. it will not overheat.

But the 60Hz means it will run 20% faster, which you need to carefully evaluate for your application. If it is a pump, probably no problem going this route since the torque is the same and higher speed at the same torque means more HP at the shaft, which is what you will need when flow increases with the higher speed. However, even if it is a pump you need to look at the pump curves because at a higher speed you may have efficiency issues to deal with.

Going the other way (using a 60 Hz motor in a 50 Hz system) is more problematic.
 
Jraef:

Thank you for the info, do you have any resources that you can recommend to better understand the V/HZ relationship and motor operation?
 
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