Air-cooled high and low temperature coolant tester is widely used in industrial production and scientific research experiments. As a key part of equipment heat dissipation, its fan system directly affects the performance and stability of the tester. However, the fan system may encounter a series of problems during use, which will be analyzed in this paper.

　　First, the fan is difficult to start or can not start

　　The difficulty or inability of the fan to start may be caused by power failure, motor damage, or control system failure. At this time, it is necessary to check whether the power line is intact, whether the motor is working normally, and whether the control system is wrong or faulty.

　　Second, the fan speed is not stable

　　Fan speed instability may be caused by power supply voltage fluctuations, motor bearing wear or fan blade imbalance. To solve this problem, it is necessary to check whether the supply voltage is stable, replace the worn motor bearings, and balance the fan blades.

　　Third, the fan noise is too large

　　The excessive noise of the fan may be caused by the friction between the fan blade and the housing, the serious wear of the bearing or the unstable installation of the fan. To reduce noise, check the clearance between the fan blades and the housing, replace the worn bearings, and reinstall the fan securely.

　　Four, the fan vibration is too large

　　Excessive fan vibration may be caused by unbalance of fan blades, bearing damage, or unstable installation foundation. To reduce vibration, it is necessary to balance the fan blades, replace the damaged bearings, and strengthen the installation foundation.

　　Fifth, the fan cooling effect is not good

　　The poor cooling effect of the fan may be caused by dust accumulation on the fan blades, blocked cooling channels, or excessive ambient temperature. To improve the heat dissipation effect, you need to periodically clean the dust on the fan blades, dredge the heat dissipation channels, and improve the ambient conditions around the device.

　　Six, the fan life is short

　　The short life of the fan may be caused by long-term overload operation, improper maintenance or design defects. In order to extend the life of the fan, it is necessary to ensure that the fan operates within the rated load, perform regular maintenance, and select a fan product with a good design and manufacturing process.

　　In summary, the fan system of the air-cooled high and low temperature coolant test machine may have problems such as start-up difficulties, unstable speed, excessive noise, excessive vibration, poor heat dissipation effect and short life. In response to these problems, users should regularly check and maintain the fan system to ensure its normal operation, in order to improve the overall performance and stability of the test machine.