Which device is used to detect ground faults in motor circuits?

A ground fault relay is specifically designed to detect ground faults in motor circuits. Ground faults occur when an unintended path forms for electrical current, typically leading to a dangerous situation including the risk of electrical shock or equipment damage. The ground fault relay continuously monitors the balance of electrical current entering and exiting the motor. If it detects an imbalance, which indicates that some current is leaking to the ground, the relay activates and can disconnect the power supply to prevent potential hazards.

While a voltage regulator, overload relay, and contactor perform important functions in motor control and protection, they do not directly detect ground faults. A voltage regulator stabilizes voltage to ensure a consistent power supply, an overload relay protects motors from excessive current that could cause overheating, and a contactor acts as a switch to control the flow of electricity. None of these devices specifically monitor for ground faults, making the ground fault relay the appropriate choice for that particular function.