The electrical disconnect for a pumping station motor can trip out under which condition?

The electrical disconnect for a pumping station motor is designed to protect the motor from potentially harmful conditions. When considering the options, the situation in which a lightning strike occurs is particularly significant because it can deliver a sudden surge of electrical current. This surge can exceed the motor's safe operating parameters, causing the disconnect to trip and thereby disconnect the motor from the power source to prevent damage or electrical fires.

In this context, a lightning strike can create a risk not only because of the high voltage but also due to the resulting energy surges, which the disconnect mechanism is intended to guard against. Hence, a properly functioning electrical disconnect should effectively trip in response to the potential overvoltage conditions caused by a lightning strike, ensuring the safety of the equipment involved.

Other conditions like pump cavitation, low temperature, or worn packing may cause operational issues or inefficiencies, but they do not typically trigger an electrical disconnect as a direct response to protect the motor from immediate electrical hazards.