During phase loss, which of the following is a typical consequence?

• A. The motor continues to run normally
• B. The motor stops immediately with no damage
• C. Current in the remaining phases increases dramatically
• D. The motor's efficiency improves

Answer: (C)

When a three‑phase motor loses one supply phase, the normal balanced three‑phase current cannot be maintained. Only two windings are energized, so the magnetic field becomes uneven and the motor tries to develop torque with an imperfect field. To produce the same or any meaningful torque under this weak, unbalanced condition, the current in the remaining two phases tends to increase significantly. That higher current, along with the unbalanced operation, leads to overheating and can cause damage if the condition isn’t cleared quickly. The motor will not run normally, and its torque and efficiency drop rather than improve.