Thermal protection of motors
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The motor nameplate indicates PTC 145 degrees Celsius; when used with ABB’s motor protection relay, the motor keeps tripping due to thermal protection, with the interval between trips ranging from 15 to 40 days. Please help: 1. Analyze the reasons for the system shutdown and the methods for detection ； 2. What is the resistance value corresponding to PTC145? Thank you
Check if it’s a problem with the motor cable, whether there are cable connectors, and if it’s overheating We used to have a motor here that kept tripping, and Ma Bao didn’t trigger any alarms; it turned out to be a problem with the cable connections.
Based on the shutdown interval and the fact that there were no previous shutdowns, it is analyzed whether the motor has developed leakage due to prolonged use, or whether its insulation has deteriorated during operation.
Check whether the motor is actually heating up. If the heating is not severe, see if there is a problem with the circuit, the resistive components, or the protection module