Difference between Single-phase and Threephase Induction Motor



The differences between a single-phase and a three-phase induction motor are given below −

  • A 1-phase induction motor requires single-phase AC supply, whereas a 3-phase induction motor need a source of 3-phase AC supply for its operation.

  • 1-phase induction motors produce low starting torque, whereas 3phase induction motors produce high starting torque.

  • The efficiency of a 1-phase induction motor is less as compared to a 3phase induction motor.

  • The power factor of a 1-phase induction motor is low, while the power factor of a 3-phase induction motor is high.

  • 1-phase induction motors are simple in construction, reliable and economical as compared to 3phase induction motors.

  • 1-phase induction motors are easy to repair and maintain as compared to a 3phase induction motor.

  • A 1-phase induction motor develops about 50% of the output power of that of a 3-phase induction motor for the same size and temperature rise.

  • A 1-phase induction motor is expensive than a 3phase induction motor of the same rating.

  • 1-phase induction motors are mainly used in low-power applications like small industries and domestic and commercial applications, while 3phase induction motors are used in high-power applications such as in large industries.

Comparison between Single-phase and Three-phase Induction Motor

The following table shows a summary of the differences between a single-phase induction motor and a three-phase induction motor −

Parameter Single-Phase Induction Motor Three-Phase Induction Motor
Supply 1-phase supply 3-phase supply
Starting Torque Low High
Efficiency Low High
Power Factor Low High
Construction Simple & robust Complex & robust
Reliability & Cost More reliable & low cost Less reliable & expensive
Maintenance Easy Difficult
Applications Used in low power applications such as in domestic appliances.
Used in high power industrial applications.
Updated on: 2021-09-18T07:43:16+05:30

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