Problems and solutions of electric blast drying oven

       Repair of the oven
　　(1) Fault phenomenon: it can be heated, but the fan cannot work.
　　(2) Failure analysis: From the analysis of the functional module composition of the oven above, it should be that the blower and its related circuits have failed.
　　Use a multimeter to measure the resistance of the running winding and the starting winding of the fan coil respectively, indicating that the coil is not blown. Because the fan is a single-phase motor driven by 220 V, the single-phase current cannot generate a rotating magnetic field. The method that needs to be adopted is to make it generate a rotating magnetic field. The common method is to use the capacitor to separate the phases. Therefore, it is suspected that the capacitor is damaged, causing the fan to fail to start. The capacitor model is CBB61, 0.8 μf/450V, measured with the 10 k resistance gear of the multimeter, the pointer basically does not move, indicating that the capacitor cannot be charged and discharged normally.
　　(3) Problem solving: Replace the capacitor. Since the capacitor of the same specification could not be purchased, replace it with a 1 μf/450 V capacitor. After the fan is turned on, the fan runs normally.
　　2.2 Maintenance of the oven
　　(1) Fault phenomenon: The oven cannot be heated, and the temperature parameters can be set on the panel.
　　(2) Failure analysis: ① The oven as a whole can be powered on, and the temperature controller panel can also be operated. It is suspected that the heating tube is damaged. Use a multimeter to measure the resistance of the heating wire, about 10 Ω, which should be normal. ②Set the target temperature on the thermostat to 70 °C, measure the voltage across the heating wire, and find that it is 0 V. Further measure the output voltage of the thermostat, and the output is 0 V. Then make a judgment that the thermostat is damaged. The temperature controller adopts single chip technology, switching power supply, and has the functions of temperature control, timing and over-temperature alarm.
　　(3) Problem solving: In order to repair the oven as soon as possible, without opening the controller to repair the components, directly replace the thermostat of the same type, and start the machine normally after the replacement.
　　in conclusion
　　In order to prolong the service life of the electric blast drying box, in terms of maintenance and maintenance, the inside of the box should be wiped and cleaned regularly, and volatile and corrosive products should not be placed in the studio. Regularly check whether the fan of the electric blast drying box is running normally. If there is any abnormal sound, turn off the machine immediately for inspection. Regularly check whether the ventilation openings of the drying box are blocked, and regularly clean up the dust.