Speed Torque Curves

[stanier]

Hi,

I am seeking the speed torque curves for two motors on separate centrifugal pump duty.

1) 250 Kw 1450 rpm 380v
2) 315 kW 1500 rpm 6000v

Any good sources I can down load from?

 

[JJPellin]

This seems like the sort of thing that would be very specific to a given motor. We have these curves on file for some of our motors but they were always provided with the original purchase of the motor. I would suggest contacting the manufacturer of the specific motors and aksing them for the curves. I have never seen any general source of these curves based on speed, power and voltage. I would expect them to depend on the motor type (synchronouos, induction) motor configuration (squirel cage), motor efficiency (standard, high, premium) and even the bearing configuration (sleeve, ball, roller).

 

[electricpete]

JP is right. The best you can get from anyone other than the manufacturer (or someone who has tested your motor) is a "typical" curve.

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[Marke]

Hello stanier

Unfortunately, JP and EP have given you the right advice. There are major differences between the speed torque curves for motors of the same size and speed. The Locked Rotor Torque can vary from less than 80% to higher than 240%. It is too dangerous to assume a generic curve! You must use the correct curve for the motor in question.
The torque speed curve is largely determined by the rotor design.

Best regards,

Mark Empson

http://www.lmphotonics.com

 

[stanier]

Thank you all for the feedback. Much as I expected. Unfortunately these motors are of Russian decent, located on a remote site in Eastern Europe and I have to do the water hammer analysis from Australia. I need the torque speed curves to model the start up of the pumps.

The approach I shall take is to estimate the best and worst case and undertake a sensitivity analysis of the pumps start up.