Electric Motor Efficiency

[sunilji]

Hi All,
I am searching for a modern, portable instrument for testing Efficiency of 3 phase Electric Motors in the range of 1 to 30 hp.
I welome replies from anyone with experience or information
Regards to All

 

[electricpete]

As you may be aware there are quite a number of different ways to measure efficiency. See IEEE112.

I'm guessing that on the small horsepower range a direct measurement is best/easiest if you can find someway to measure the output power (shaft horsepower=brake horsepower).

Measuring the input power is trivial using any of a variety of instruments that measure current, voltage, and angle between them.

There are quite a variety of other more complex ways to do it without actually loading up the motor. Those are more attractive in the higher horsepower range where mechancial loading of the motor is difficult/expensive. These methods also offer a benefit of segregating the losses into the various categories... stator I^2R, rotor I^2R, core losses, frction and windage, stray losses.

 

[kuwait]

there definitely is available in market meters with plug in type CTs which measure not only the instantaneous power but also kva,kvar,p.f.,V,I etc. I used one by ITT germany even one madras based firm markets one with printout option.