Three phase induction motors have several advantages including simple and rugged construction, high reliability, low cost, and high efficiency which require less maintenance. However, they also have some disadvantages such as variable speed when load changes, low starting torque, and reduced efficiency when speed varies.

1. THREE PHASE INDUCTION MOTORS

5. Advantages:
1. Simple and rugged construction
2. High reliability
3. Low cost
4. High efficiency
5. Less maintenance
6. Self starting
Disadvantages:
1. The speed is not constant, when load is varied
2. Low starting torque
3. Reduction in efficiency when speed is varied