A DC centrifugal fan is prone to overload under certain circumstances. Overload can occur due to various reasons such as blocked air inlets or outlets, improper voltage supply fluctuations, and mechanical faults within the fan itself. When an overload situation happens, the fan motor is at risk of overheating and being damaged.

One common method of overload protection is the use of thermal fuses. These fuses are designed to melt at a certain temperature. When the motor temperature rises above the safe limit due to overload, the thermal fuse breaks the circuit, stopping the fan and preventing further damage. Another approach is the installation of current sensors. These sensors monitor the current flowing through the motor. If the current exceeds a preset value, which indicates an overload, a control circuit can be activated to either reduce the voltage supplied to the motor or shut it down completely.

Regular maintenance is also crucial for overload protection. Cleaning the fan blades and ducts regularly can prevent blockages that could lead to overload. Additionally, checking the alignment of the fan components and ensuring proper lubrication of moving parts can reduce the mechanical stress on the motor, minimizing the chances of overload.