The values for efficiency and power factor are not the same at high values of slip as at operation at rated duty.I tried my level best.I am not able to see the wrong in the calculation.Can't you do any thing about it?
I thought my comment "a slip up on your part" might have been a clue.
In round figures, your example would give half the volts but three times the current.
The power factor simply cannot be the same. With the higher current, the losses will be greater so the power factor simply cannot be the same.
Simple. The auto-transformer is a reduced voltage starter. It reduces the starting and run up current before switching (preferably with closed transition) to full voltage.If you do not mind,please give a description how an auto-transformer starter works and compare the current it delivers to motor with those you mentioned.You will then see those are starting currents of motor and not its running currents.
We don't do many of those. The last one of those we did was a couple of years ago and rated at 6600kW.
But what does that have to do with running currents?
That rotor resistor is an optional item.
Install resistors. Exercise caution when wiring as the
resistor element operates at 375 ?C (707?F).
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