This is a 3-phase AC machine. This is mechanically coupled to a breakdrum to provide loading. The shaft of the machine is coupled a drum. In turn the drum is connected to mechanical weighing pan by means of a belt. Rotating the screws provided on either sides of the belt can adjust the belt tension. There by it is possible to load the shaft of the 3-phase motor with a defined tension. The difference in the scale reading, provides the tension, the shaft is subjected to. As a result of this the current in the windings are varied. By noting the readings of the associated meters and the difference in the weighing pan readings, the load characters of the motor can be evaluated.

This is an arrangement of a 3-phase induction motor, mechanically coupled to a DC generator.