460V 60Hz motor on 480V 50Hz System

[Kani77]

Hi,

Can I use 15HP 460V 60Hz motor on 480V 50Hz System? What are the formulas to calculate FLA of this motor at 480V 50Hz. Please provide a calculation example.

Thanks,
Kani

 

[davidbeach]

Yes. The rest is left as an exercise for the student...

 

[Mbrooke]

Unless the motor is specifically listed for 50Hz, it will overheat. Otherwise the voltage must be reduced to about 415 volts. The motor will turn slower and output about 18% less HP off the top of my head.

Someone like J-Raef will be able to give a much more detailed and technically correct answer.

 

[waross]

The Volts per Hertz will be exceeded and the motor will saturate.
The motor will burn up long before you complete the calculations, even if your are a fast calculator.
Rated voltage = 460 Volts.
V/Hz = 7.67 V/Hz.
Safe 50 Hz V = 50 Hz x 7.67 V/Hz. = 383 Volts safe 50 Hz voltage.
Guesstimate saturation at 115% over voltage = 440 Volts, 50 Hz.
As the voltage rises above saturation the current is limited by the air core inductive reactance and the winding resistance.
You will have about 480V - 440V = 40 Volts driving current through the resistance of the motor windings.
The current will be excessive.
By now the smoke is coming out.
How accurately do you want to calculate the impending time of death?

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[waross]

By the way, just for interest, in what part of the world have you encountered 480 Volts, 50 Hz?

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[waross]

50Hz/60Hz = 83.33% of the 60 Hz speed.
1 - 83.33% = 16.67% slower.
Or speed and HP = 5/6 from 60 Hz to 50 Hz.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[itsmoked]

One of yours Bill... BC, Canada.
Didn't you know you have 480V/50Hz??

Keith Cress
kcress -

http://www.flaminsystems.com