Fan Thermal Fuse
The possible problem is that when the circuit inside the electric fan fails, it will cause a short circuit. At this time, if there is a fuse, the instantaneous current is very large, the fuse will be broken, thus playing a protective role. If it is lost, it will not play a protective role and may affect the normal use of the upper-level power supply!
Maintenance of electric fan motor not rotating The main reasons for the motor not rotating are: winding open circuit, lack of oil to hold the shaft, abnormal capacitor, etc. Judging from the maintenance practice of electric fans, the latter two faults are mostly. For non-rotating electric fans, my maintenance steps are to measure the plug, rotate the motor, measure the capacitance, and then process it. The first step is to measure the operation of the electric fan and the speed regulating winding. Rotate the electric fan first. When you hear a rattling sound, the electric fan is normal. If there is no clicking sound, the electric fan is damaged. If there is no resistance value, it may be that the motor windings have been burnt and broken. For a motor with a thermal fuse, the thermal fuse may be an open circuit. You should also disassemble the motor and take a look. If it is only an open circuit, short-circuit the thermal fuse to return to normal. The gear switches are all damaged, but the possibility is unlikely. The second step is to check whether it is holding the shaft, disassemble the electric fan guard, and rotate the motor shaft by hand. If it does not turn, it means that the motor is holding the shaft seriously. Disassemble the motor, first remove the oil and rust on the front and rear bushings and the motor shaft, and then add enough sewing machine oil to the linoleum of the front and rear bushings. Most electric fans can be trouble-free. The third step is to measure the starting capacitance. If the motor shaft rotates flexibly, it is necessary to measure the starting capacitance of the electric fan motor. First of all, use a multimeter to measure the resistance value of the motor starting capacitor at both ends of the motor starting capacitor, the whole electric fan motor running, starting and speed regulating winding, that is, the resistance value of the black and motor leads. Maintenance of active electric fans For electric fans with active motors, I can do it in one step based on the actual situation. Rather than performing maintenance step by step as described above. If the user says, the electric fan rotates slowly first, and then gradually becomes faster. According to experience, the motor is generally holding the shaft slightly. The reason is the lack of lubricating oil for electric fans at the initial stage. Disassemble the electric fan motor directly, add enough sewing machine oil to the linoleum of the front and rear bushings, and it can usually be repaired. Remote control electric fan, turn on the troubleshooting when power is on. The current remote control electric fan control actuators are basically thyristors. It can be seen from the principle that the thyristor is essentially equivalent to the switch thyristor breakdown is equivalent to the switch being turned on. Of course the electric fan will turn when the power is turned on. For example, when a floor-standing remote control electric fan is used, the remote control functions are basically normal. However, after the electric fan is turned off, it is not unplugged to touch the electric fan, and there is a clear sense of vibration, and the electric fan makes a buzzing sound, especially at night, it is obvious that the fan blades of the electric fan are also rotating slowly. Because the control functions are basically normal, the MCU is normal, and it can be seen from the above principles that the SCR is faulty.