Objective: To obtain the performance characteristic of 3-phase induction motor by load test and by loss summation method. Preview : On no load, the power factor of an induction motor is very low and it slowly improves with load and attains a value around 0.85 on full load. Efficiency starts from zero on no load; increases with load, reaches a maximum at about 80% of rated load and then starts decreasing. One of the methods of loading an induction motor is to couple it to a dc machine, which is run as a dynamometer or with the help of a brake drum arrangement. |
