Motor protection is the isolation of the motor from the main supply in the event of an abnormal condition in the operating state of an motor (i.e. when the motor is supplied with electricity).
Motor protection mainly consists of
- Sensors : to detect real-time engine parameters. An engine can encounter different types of faults. In order to detect the operating parameters of a motor, it is necessary that certain sensors such as temperature (winding and rolling), current, voltage, rotor speed sensors are installed.
- Relays: the operating parameters of these sensors are supplied at the input of these relays. We can have several relays to identify different types of faults. The role of a relay is to ensure the proper functioning of the motor and to differentiate it from fault conditions. It is part of the control circuit. The relay circuit sends a trip command to the circuit breaker when a fault condition is identified. It can be an electromechanical relay or a digital relay. The advantage of digital relays is that you can have a unified relay to perform all the protection-related functions. This eliminates the need for multiple bulky relays that are subject to maintenance.
- Circuit breakers: to isolate the machine from the main power system. The size and ratings of the circuit breaker depend on the specifications of the motor.