1, see the accompanying documents, "Cooling Fan Manufacturer" motor came with a manual, product certification, electrical wiring diagrams and the packing list to check the packing list, check the parts.
2, see the motor fan shape, look carefully at the fan motor and fan grille there is an obvious distortion. Turn the fan should be light and flexible, not always stop at the same location.
3, see the start-up performance, start-up performance is good or bad is an important quality indicators "Cooling Fan Manufacturer" motor. When tested in the slow speed, the power supply 85% of rated voltage, fan motor should start from a standstill, and the normal operation of a motor fan from the start to the normal operation of the shorter time required to start, the better the performance of the motor fan .
4, see speed performance, the power, the fan should not be part of the mechanical drive abnormal noise. Fans in high, medium and low speed, the motor and blades should be smooth, vibration, low noise. Motor fan shook his head, shut down should be agile, non-stop, arrest and jitter.
5. Look for leaks, electric fan motor after the hand touch if Ma electric feeling, with test pencil test, test pencil also has a light-emitting display, you can determine the shell leakage, can not be.
6, see "Cooling Fan Manufacturer" motor continuous operation, the fan after 2 hours of continuous operation, if the head of the shell surface hot, indicating the temperature is too high, you can not use.