Smart Office,include computer and Computer Applications, notebook and computer motherboards, optical drives, hard disks and their components, additional cards, power supply unit and other computer peripherals. The power consumption of electronic components in the main cabinet will produce higher heat. To prevent heat accumulation, fans are installed to cool down. If the fans run for a long time or are used for a long time, motor bearing wear, wear off, or rotor running instability and other problems can lead to motor overheating or burn the motor, when the fan is not running, in this case, the fan is not able to cool the CPU, after a period of time, the CPU is likely to be burned out due to the high ambient temperature. In order to prevent the CPU from being burned out due to the stop of the fan, the fan motor should be protected by a thermal protector. When the motor is overheated due to various reasons, the power cut off protects the motor.