Thermal relays are commonly used in motors against overcurrent, which is drawn because of:

Thermal relays are specifically designed to protect motors from overcurrent conditions primarily caused by overloads. When a motor operates under a load greater than its rated capacity for an extended period, it draws an excessive amount of current. This continuous high current flow leads to overheating, which can damage the motor.

The thermal relay operates by using a bimetallic element that bends in response to the heat generated by the excessive current. As the temperature rises, the bimetallic strip will bend and eventually trip the circuit, disconnecting power to the motor before any serious damage occurs. This mechanism is ideal for overload conditions as it ensures that the motor can only operate safely within its specified current rating.

Other potential causes of overcurrent, such as short circuits, voltage spikes, and ground faults, are not primarily addressed by thermal relays. Short circuits usually involve a drastic rise in current in a very brief moment, which requires a different protection method, typically involving instantaneous trip devices like circuit breakers. Voltage spikes can lead to insulation breakdown rather than current draw issues. Ground faults also need protection focused on detecting ground paths, which thermal relays are not designed to do effectively.

Thus, thermal relays play a vital role in safeguarding against overload conditions, making