Under the necessary conditions of 5mA leakage current and AC500V for 60 seconds, there is no abnormality between the fan frame and the transmission line, which proves that the insulation is excellent.

2. Insulation characteristic impedance

Under the necessary conditions of 500V DC, the positive resistance of the frame and the transmission line is not less than 10MΩ

Three, swivel lock protection measures

1. Several fan blades are connected and fixed, and their rotation is restricted. If the fan and electronic components are not easily damaged, and the restricted rotation parts are loosened, the fan can automatically restart the system.

2. The cooling fan with high current or without the basic function of Auto start cannot be locked for a long time, otherwise the cooling fan will be damaged by overheating.

3. For fans with low current or with Auto start function, lock the fan blades in the power-on rotation state for 72 hours, release the locked blades, and the fan will automatically restart immediately, which proves that the fan is normal.

4. Polarity maintenance

Under the normal voltage standard, as long as the power supply is reversed and the cooling fan is plugged in for 15 minutes, then the power supply is turned off and the two poles are connected again, and all functions will be normal.