The fan of the purchase skills

1. Look at random files Each fan's random file includes the instruction manual, product certification, electrical circuit diagram and packing list, the purchase should be in accordance with the packing list inventory, check the number and quality of parts.
2. Look at the screen and the exhaust window fans is obvious deformation in the assembly of the fan fan cover, with a pen pointing to the highest point of a fan, slowly move the fan, the other few leaves corresponding to the tip of the pen The distance should be very close, and then turn the fan, pay attention to observe whether the rotation is light and flexible, and can stop at any position.
3. To see whether the control mechanism is flexible control mechanism including speed control switch, timing knob, shaking his head switch, lighting switch, etc., these control agencies should be flexible operation, reliable contact. On the speed control, do not allow two blocks at the same time connected or a block can not go on the phenomenon. Press the stop button, the speed of the key should be normal reset.
4. Look at the activities of some of the performance fan fan head overlooking the angle of the operation of flexible, tight lock, adjust to the maximum angle or shaking his head to the final position, the net cover are not collided with the fan pillars. Fan operation, the stability is better, can not be dumped, shaking his head should not be less than 60-80 degrees.
5. Start performance performance Start performance is an important fan of quality indicators. Inspection, should be transferred in the slow speed, and the power supply rated voltage of 85%, that is, with a voltage regulator to 220 volts to 187 volts to start the fan, electric industrial fans should be able to start from the static, and normal operation, The shorter the time required for a fan to start from normal operation, the better the start-up performance of the fan motor.
6. To see the operation and speed performance power after the shaking his head switch back and forth several times to check whether the failure or assembly too tight, in this process, the fan mechanical transmission part should not have abnormal noise. Fan in high, medium and low speed operation, the motor and fan should be smooth, small vibration, low noise. Fan shaking his head, shut down should be agile, no intermittent, stagnation and jitter phenomenon, the block speed difference should be obvious, the air angle the greater the better. When the fan stops, the shaft axial clearance does not exceed 0.5 cm, the gap is too large, the operation will cause axial movement and impact sound.
7. to see if the leakage of electric power, if the hand touched a strong hemp inductance, test with a pen test, test pen will be light display, can determine the shell leakage, can not be used.
8. to see the continuous operation of the fan performance Fan continuous operation after 2 hours, if the nose shell surface hot, indicating that the temperature is too high, can not be selected. Under normal circumstances, the nose shell surface temperature below 50 ℃, there will be no very hot feeling.