1. Current Monitoring: The Most Direct Electrical Signal
Use a clamp meter or control system to monitor the operating current of the drive motor in real time.
If the current consistently exceeds 1.1 times the motor's rated current, it can be determined as an overload.
If the servo drive displays OL1/OL2 fault codes, it also indicates an overload problem on the motor or load side.
2. Abnormal Temperature Increase: Typical Physical Manifestations
Observe the temperature of the reducer or motor casing:
Under normal circumstances, the winding temperature of a Class B insulated motor should not exceed 130℃;
If the surface temperature exceeds 70℃ (unbearable to the touch), it may be overheated.
Overload will lead to increased friction and a rapid rise in oil temperature. The reducer oil sump temperature rise should not exceed 35℃, and the maximum oil temperature should generally not exceed 85–90℃.
3. Increased Vibration and Noise: A Signal of Excessive Mechanical Load
During normal operation, a uniform, low-pitched "humming" sound should be emitted.
Overload may cause the following:
High-pitched whistling: Indicates poor gear meshing or damaged bearings.
Periodic impact sound: Indicates a loose coupling or worn pulley.
Severe vibration: Indicates transmission system imbalance; vibration exceeding 2.8 mm/s is abnormal.
4. Abnormal operating parameters: Indirectly reflect load status.
Speed drop: Under stable power supply, if the motor speed is significantly lower than the rated value, it indicates that the load is too heavy, resulting in insufficient torque.
Large pressure fluctuations: Abnormal outlet pressure of the circulating pump may be due to unstable flow caused by overload.
Frequent triggering of protection shutdowns: Such as thermal relay tripping, PLC "overload" alarms, etc., are signs that the system automatically identifies overload.
5. Comprehensive Judgment Recommendations
Combining sensory inspection and instrument testing:
Simple Judgment Method: Touch temperature measurement + screwdriver listening (press against the bearing area close to the ear);
Scientific Testing Method: Use an infrared thermometer, vibration meter, and ammeter to collect data and compare it with the equipment's factory standards or historical operating curves.
