A pump induction motor is switched on to a supply 30% lower than its rated voltage. The pump runs. What will eventually happen ? It will____________?
Correct answer: D. get heated and subsequently get damaged
- A. stall after sometime
- B. stall immediately
- C. continue to run at lower speed without damage
- D. get heated and subsequently get damaged
Explanation
Induction-motor torque is approximately proportional to the square of applied voltage, so a 30% voltage reduction leaves only about 49% of normal torque. The motor draws excessive current to drive the pump, overheats, and may eventually be damaged.
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