(1) The surface of the motor protector body should be kept clean. Excessive dust and moisture on the surface can easily reduce the overall insulation resistance of the protector and induce malfunctions.
(2) Check whether the output, input terminals, contacts or connecting plug-ins of the protector are in good contact, and whether there are phenomena such as overheating, oxidation, and damage to the connecting wires due to poor contact, especially if the three-phase current main circuit is in poor contact or the wire diameter is not selected. Properly overheating will affect the shell.
(3) Check whether the display status of the motor protector indicator, digital tube, and LCD screen is normal.
(4) Check whether the motor protector and connector are installed firmly.
(5) Check whether the setting current value of the motor protector is changed or deviated from the original setting value, especially the use of potentiometer knobs and dial switches to operate devices that can easily be adjusted by the operator to change the original setting value.
(6) Check whether the cooling and ventilation system of the motor is blocked, whether there are abnormal noises during the operation of the motor, whether the insulation value is reduced, whether the AC contactor contacts are damaged, whether there is noise during pull-in, etc.
(7) On-site inspection of the main functions of the protector: After the protector is activated, first observe, query, display or indicate whether it is correct, such as fault type, overcurrent value, motor thermal power status, etc.