Which of the following parameters is NOT typically checked during a motor protection relay test?

In the context of motor protection relay testing, the physical appearance of the motor is not typically a parameter that is measured or evaluated during the test. The focus of motor protection relay testing is primarily on the operational characteristics and performance of the relay itself in relation to the electrical parameters it monitors.

Voltage measurement is essential in ensuring that the relay is receiving the correct input levels, which is crucial for accurate protection and operation. Current measurement is similarly vital, as relays are designed to monitor the current flowing to the motor to detect overload conditions and phase imbalances. Response times are also tested to verify that the relay reacts within the specified interval when abnormal conditions, such as overload or fault, occur. This ensures that the motor can be quickly disconnected to prevent damage.

While the physical appearance of the motor—such as signs of wear or damage—can be important in a comprehensive maintenance approach, it is not a direct function of the motor protection relay and, therefore, is not typically included in the testing parameters for relay performance.