Reversing the phases of a running AC induction motor causes it to act as a generator, sending power back to the source and significantly slowing down before reversing direction. This process resembles regenerative braking but is not classified as such, as it can lead to high current draw from the supply. The sudden phase reversal may also create arcing at the terminals due to the motor's regenerative behavior. Additionally, the motor could trip overloads, triggering automatic systems like standby fans or pumps. Overall, the operation can be hazardous and lead to mechanical failure if not managed properly.