(a) Induction motors

A. E. Averrett: Regarding the separation of copper losses, there seems to be a tendency on the part of some users to want bar-wound stators on account of the ease of repair. You can make a bar-wound stator with rather deep bars, but if you have a rotor that is bar-wound also and assume that the losses are practically all in the rotor, these will disappear at synchronous speed and you will apparently have a more efficient machine than you really have, if all the losses are taken into consideration. But you can actually get the loss by taking out the rotor and measuring the impedance of the stator alone by wattmeters, which will show up the losses correctly if the tests are made carefully.