Aboutcleggsan Expertise All technical areas of Electronics Engineering.
Experience BSEE, MBA, Design, R&D, University Research.
Senior Life Member of IEEE. Life Fellow of AES.
Organizations IEEE, Consumer Electronics Society, Audio Engineering Society.
Broad teaching experience; work experience mostly in consumer electronics and conversion from analog to digital technologies. Pioneer in digital audio at all levels.
Question Dear Sirs,
We are running a 22 kw motor with an Inverter. In normal running, the motor is running good. But the motor temperature is going very high when we reduce the speed of the motor. Kindly advise the reason please.
Thanks & Regards,
Muralidharan.T
Answer That may be normal. Some motors use more current when speed goes down because the lower speed drops the inductance characteristics due to lower currents in the field coils. Also, the pf may increase at lower speeds causing much more reactive current and therefore more IR drop across the coils - and more I*2 x R heat losses.
You may want to look at the inverter as well to see how it is handling the pf angle. If you have means, measure the current and pf angle as the speed is reduced.
Finally, if the loading on the motor is remaining constant, but the speed is being reduced, it could simply be that you are overloading the motor under that lower speed.
