1. From the inside of the motor is concerned, "Mini Air Cooling Fan" internal protection devices, there is a thermal circuit breaker is part of the coil windings shorted, resulting in a sharp increase in heat, open circuit breakers, motor under such circumstances, the general strike . This rarely happens.
2. Another is the "Mini Air Cooling Fan" start capacitance becomes smaller, although the nameplate reads those parameters, but a long time, the capacitance is reduced, leading to reduced starting torque of the motor, can not drive the load. This simple, remove the capacitors, go to a new one, the same model should be no problem. But the best for a 20% larger than the original, and will get better results.
3. Shaft axial "Mini Air Cooling Fan" motor gap is too large can cause can not drag the load. If you are disassembling the motor shaft axial gap is too large to be adjusted by adjusting the shims. When installing the motor, the rotor and the bearing must be concentric job, slowly tightening the screws diagonally want, and then use a screwdriver to knock wood shaft, making concentric. Remove the motor is simple, but not re-installed back casually back together, do not occur in the case of the above, or direct repair "bad".