An alternator has a phase sequence of RYB. In case the field current is reversed, the phase sequence will become
An alternator has a phase sequence of RYB. In case the field current is reversed, the phase sequence will become
Right Answer is:
Motor will continue to run in the same direction
SOLUTION
Reversing an Alternator
- The direction of rotation of an alternator is determined by its starting direction, as initiated by induction-motor action.
- Thus, to reverse the direction of an alternator, it is necessary to first stop the motor and then reverse the phase sequence of the three-phase connections at the stator like an induction motor.
- The direction of rotation of a 3-phase alternator can be changed by altering the phase sequence of the supply. I.e from RBY to RYB. Doing so will change the direction of rotation from clockwise to anticlockwise.
- Reversing the current to the field windings of Synchronous machine (alternator) will not affect the direction of rotation. If the current in the field winding is reversed the motor will run in the same direction. The field side will only slip through a pole-pitch due to the reversal of the polarities of the field poles.
