A change from ABC phase sequence to ACB phase sequence will cause the motor to:

A change from ABC phase sequence to ACB phase sequence will cause the motor to:

• A. Stop
• B. Run in the same direction
• C. Reverse direction
• D. Freely accelerate

Answer: (C)

The rotating magnetic field in a three-phase motor depends on the order the windings are energized. With a sequence of phases energizing in the order ABC, the field rotates in one direction. If you swap two phases to get ACB, the energizing order is reversed, so the rotating magnetic field spins the other way. The rotor then tends to follow that reversed field, causing the motor to run in the opposite direction. It won’t stop or freely accelerate just from changing the sequence; the speed is set by supply frequency and load, while direction is determined by the phase sequence.

The rotating magnetic field in a three-phase motor depends on the order the windings are energized. With a sequence of phases energizing in the order ABC, the field rotates in one direction. If you swap two phases to get ACB, the energizing order is reversed, so the rotating magnetic field spins the other way. The rotor then tends to follow that reversed field, causing the motor to run in the opposite direction. It won’t stop or freely accelerate just from changing the sequence; the speed is set by supply frequency and load, while direction is determined by the phase sequence.