High temperature resistant motor winding flexible cable is a type of cable with special properties, mainly used for connecting motor windings and power transmission in high-temperature environments.

Key points for daily maintenance of cables

（1） Regular visual inspection

Inspection cycle: The inspection cycle is determined based on the operating environment of the motor, and is generally checked every 3 months under normal conditions; Check once a month in harsh environments (high temperature, corrosion, dust). ​

Inspection content: Check whether the insulation layer of the cable is damaged, cracked, discolored, softened, etc; Check whether the connection between the cable and the terminal block is firm, whether there are any loose or heating marks (such as discoloration or oxidation of the terminal); Check if there are any foreign objects blocking the cable laying path and if it is in contact with high-temperature components. If the insulation layer of the cable is found to be damaged, it should be repaired promptly with high-temperature resistant insulation tape; If the terminal oxidizes, it needs to be sanded clean with sandpaper and the screws tightened again. ​

（2） Insulation resistance testing

Testing cycle: The insulation resistance of the cable should be tested every 6 months. During the testing, the motor power supply should be disconnected, and the connection between the cable, motor winding, and power supply should be removed. ​

Testing method: Use a 1000V megohmmeter (low voltage cable) or a 2500V megohmmeter (high voltage cable) to measure the insulation resistance of the cable. Before measurement, the megohmmeter should be subjected to short circuit and open circuit tests (the pointer should point to 0 during the short circuit test and to ∞ during the open circuit test). When measuring, connect the "L" end of the shaking table to the copper core of the cable and the "E" end to the insulation layer of the cable. Shake the shaking table at a speed of 120r/min and read the insulation resistance value after 1 minute. If the insulation resistance value is lower than 0.5M Ω (low-voltage cable), the cable needs to be dried (such as using hot air drying method), and retested after drying. If the insulation resistance still cannot be restored, the cable needs to be replaced. ​

（3） Temperature monitoring

Monitoring method: Use an infrared thermometer to measure the surface temperature of the cable, with a focus on monitoring the connection between the cable and the terminal block, as well as the cable section near the high-temperature components of the motor. The measurement should be carried out after the motor has been running normally for 1 hour to ensure the accuracy of the measurement data. ​

Temperature standard: The surface temperature of the cable should not exceed its long-term operating temperature limit, and the difference with the temperature of the motor winding should not exceed 10 ℃. For example, the surface temperature of YGH-150 cable should not exceed 150 ℃. If the temperature of the motor winding is 145 ℃, the surface temperature of the cable should not exceed 155 ℃ (with a 5 ℃ margin reserved). If the surface temperature of the cable exceeds the specified value, it is necessary to check whether the cable is overloaded and whether the laying path is reasonable. Timely measures should be taken to reduce the cable temperature (such as reducing the motor load and adjusting the cable laying position). ​

（4） Fault handling

Insulation layer damage: If there is a small area of damage to the cable insulation layer, you can first use sandpaper to polish the insulation layer around the damaged area, and then wrap 3-4 layers of high-temperature resistant insulation tape. When wrapping, overlap half the width of the tape to ensure good sealing. If the damaged area is large (exceeding 1cm ²), the entire cable section needs to be replaced. ​

Poor terminal contact: If the connection between the cable and the terminal is loose, the power supply should be disconnected first, the terminal should be removed, the oxide layer of the copper core of the terminal and cable should be polished with sandpaper, and then the terminal should be re crimped and the screws tightened. If the terminal is deformed or damaged, it needs to be replaced with a new high-temperature resistant terminal. ​

Cable aging: If the cable undergoes severe aging (such as insulation layer cracking, hardening, or significant decrease in insulation resistance), it is necessary to replace the cable in a timely manner. When replacing, a cable with the same specifications and temperature resistance level as the original cable should be selected to ensure the normal operation of the motor.