Many companies in the production of "24V DC Cooling Fan" course will take place one way or another fault, most of the reason may be due to the heat caused by, the following stall during rotation judge raised the possibility of the corresponding analysis. Rotor rotating stall frequency: When the normal operation of the cooling fan, "24V DC Cooling Fan" with the direction of the impeller rotor is in the same direction, an exception occurs when the fluid direction, the rotor is abnormal vibration. So this is the reason causing the fan rotating stall. To prevent accidents cooling fan failure caused unnecessary losses, we must make improvements from the design. Thus fundamental to dispel criticism, to change nature. These are electronic "24V DC Cooling Fan" summary of some of the relevant manufacturers.