If the phase sequence is unchanged, rotation will ____________

If the phase sequence is unchanged, rotation will ____________

• A. Continue to speed up
• B. Reverse direction
• C. Stop
• D. Remain unchanged

Answer: (D)

Phase sequence sets the direction of the rotating magnetic field in a three-phase machine. If you keep the sequence the same, the rotating field continues to rotate in the same direction. The speed of rotation, for a given supply frequency and pole count, is determined by those electrical parameters and load (through slip in an induction machine), not by the phase order. So with the sequence unchanged, the rotation stays the same direction and at the same speed under the same conditions.

Phase sequence sets the direction of the rotating magnetic field in a three-phase machine. If you keep the sequence the same, the rotating field continues to rotate in the same direction. The speed of rotation, for a given supply frequency and pole count, is determined by those electrical parameters and load (through slip in an induction machine), not by the phase order. So with the sequence unchanged, the rotation stays the same direction and at the same speed under the same conditions.