Correct option is A
Overload protection in a motor circuit is specifically designed to protect the motor from sustained over-currents. Over-current conditions occur when the motor draws more current than its rated capacity for an extended period, which can lead to overheating and potential damage to the motor windings. This type of protection ensures that the motor is turned off or disconnected from the power supply before any damage occurs due to prolonged excessive current.
Short circuits, over-voltage, and earth leakage currents require different protection mechanisms, such as fuses, circuit breakers, and earth leakage protection devices, respectively.
Therefore, the correct answer is option (a) Sustained over-currents.
