What happens if You Connect a 3-Phase Induction Motorto 1-Phase Supply?

What happens if You Connect
a 3-Phase Induction Motor
to 1-Phase Supply?

Answer

When a single-phase supply is given to a three-phase induction motor, the following effects can occur:

1. The motor draws more current from the remaining two supply lines, approximately twice the earlier current.

2. The torque and speed characteristic is seriously affected when a 3-phase motor operates on a single phase. Torque developed is reduced and the motor will continue to run if the load is less.

3. If the motor is running, it will stop immediately (due to open circuit).

4. If the motor is stopped, it won’t start at all (due to the absence of current as well as RMF).

5. During single phasing, no current passes through one line while the other two lines carry excess current depending on the load.

6. The other two lines carry 2.4 times normal line current for the load.