# 50hz To 60hz Conversion

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I have a 3 phase, two speed motor that is rated at 380 volt/50 Hz which is being used in a 460 volt/60 Hz application. I understand that this is not an issue since the V/Hz ratio is relatively unchanged. My question in in regards to kW rating, name plate amps and cosphi. RPM is easy enough to calculate, but I do not know if everything else is as easy as using the ratio of the frequency change. Can anyone tell me how to calculate the kW, amps and cosphi. The dataplate on the motor is currently:

380-400 volt / 50 Hz / 1460 RPM / 6.8 kW / 14.1 Amps / cosphi 0.84

380-400 volt / 50 Hz / 730 RPM / 1.4 kW / 5.1 Amps / cosphi 0.55

Thanks,

Frank

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I have a 3 phase, two speed motor that is rated at 380 volt/50 Hz which is being used in a 460 volt/60 Hz application. I understand that this is not an issue since the V/Hz ratio is relatively unchanged. My question in in regards to kW rating, name plate amps and cosphi. RPM is easy enough to calculate, but I do not know if everything else is as easy as using the ratio of the frequency change. Can anyone tell me how to calculate the kW, amps and cosphi. The dataplate on the motor is currently:

380-400 volt / 50 Hz / 1460 RPM / 6.8 kW / 14.1 Amps / cosphi 0.84

380-400 volt / 50 Hz / 730 RPM / 1.4 kW / 5.1 Amps / cosphi 0.55

Thanks,

Frank

kW, as in shaft power, will increase by the speed difference ratio because the formula for calculating that is based on RPM.

Power factor and efficiency should remain the same, as should current.

"He's not dead, he's just pinin' for the fjords!"
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I agree with jraef.

Provided that the V/Hz ratio is the same, the power available will change with the synchronous speed. If you run a 380V 50Hz motor on 460V 60Hz the power sill increase by the ratio of 60/50

Best regards

Mark.

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