How to keep the permanent magnet motor working normally without demagnetization or burning.

1. Keep the permanent magnet motor working at rated current

The main reasons for the overload operation of the permanent magnet motor are due to the excessive load being driven, the voltage being too low, or the driven machinery being stuck. If the overload time is too long, the permanent magnet motor will absorb a large amount of active power from the power grid, the current will increase, and the temperature will rise. At high temperatures, the insulation of the permanent magnet motor will age and the magnets will lose magnetism. Therefore, when the permanent magnet motor is in operation, attention should be paid to regularly checking whether the transmission device is flexible and reliable; whether the concentricity of the coupling is standard; the flexibility of the gear transmission, etc. If stuck phenomenon is found, the machine should be stopped to find out the cause and eliminate the fault before running again.

2. Always check whether the three-phase current of the permanent magnet motor is balanced.

For a three-phase AC permanent magnet motor, the difference between one phase current of the three-phase current and the average value of the other two currents is not allowed to exceed 10%. Only in this way can the safe operation of the permanent magnet motor be maintained. If it exceeds, it indicates that the permanent magnet motor is faulty and must be identified. .

3. Check the temperature of the permanent magnet motor. Always check the temperature of the bearings, stator, casing and other parts of the permanent magnet motor for abnormal changes.

Check whether the bearings of the permanent magnet motor are overheated and lack oil. If the temperature rise near the bearing is found to be too high, stop the machine and check whether there are cracks, scratches or defects on the surface of the rolling elements and raceways of the bearing. Whether the ring rotates on the axis, etc. If any of the above phenomena occurs, the bearings must be updated before work can be resumed.

4. Observe whether the permanent magnet motor has any vibration or loud noise.

If the permanent magnet motor vibrates, it will cause the load part connected to it to be non-concentric, causing the load of the permanent magnet motor to increase, causing overload operation and burning the motor. Therefore, when the permanent magnet motor is in operation, especially high-power permanent magnet motors, it is necessary to frequently check whether the anchor bolts, end covers, bearing glands, etc. are loose, whether the grounding device is reliable, and solve problems in a timely manner.

5. Keep the permanent magnet motor clean

When the permanent magnet motor is running, dust, water stains and other debris are not allowed within at least 3m around the air inlet to prevent it from being sucked into the motor and forming a short-circuit medium, or damaging the wire insulation, causing a short circuit and burning the motor. Therefore, it is necessary to ensure Only when the permanent magnet motor has sufficient insulation resistance and a good ventilation and cooling environment can the permanent magnet motor maintain a safe and stable working condition during long-term operation.