Failure analysis and treatment of electronic expansion valve
There will be one or another malfunction of the EEV. When the fault occurs, it is necessary to analyze the fault, so as to take correct measures to solve the fault of the electronic expansion valve. The faults of electronic expansion valve in Yulong, Jiaxing and Beijing can be roughly divided into three categories: one is electronic throttle component failure, one is nozzle component failure, the other is valve body component failure. The following are the fault analysis and treatment methods summarized for these three types of faults.
One. Failure analysis and treatment of electronic throttle components
Open the shell of the electronic throttle element, turn on the power supply of the device, and hold the coil of the electronic expansion valve by hand to check whether there is any action and whether the coil has working indication. If there is no action, check according to the following steps:
1. Check whether the coil body of EEV is broken. If so, re connect the wires.
2 check whether the connection between the coil of the electronic expansion valve and the main board connector is loose. If so, please re insert.
3. Check whether there is fault alarm on the main board and eliminate other factors.
4 检查主板输出电压是否正常DC 12V。
4. Check whether the output voltage of main board is normal DC 12V.
5 .measure whether the coil resistance of the electronic expansion valve is normal 463. If abnormal, replace the coil.
Two. Failure analysis and treatment of nozzle
Apply soapy water to all welding parts and nut connection parts of the pipe to see if there are bubbles. If there is leakage, re weld or adjust.
2. Before re welding the pipeline, the valve body should be protected according to the use requirements, and the system should be cleaned.
3. Fault analysis and treatment of valve body
After confirming that the resistance and connector of the coil part are normal, turn on the power supply of the unit for operation, hold the valve body with your hand, and feel whether the valve body acts. The time from fully open to fully closed valve body is about 6 seconds. When the valve body is in the fully open or fully closed position, if the voltage is continuously applied, the valve body will emit a great jamming tower sound. If the action time is too short or does not act, the valve body limiting mechanism or valve needle may be stuck. Please perform the following operations:
1 remove the coil and check whether there are collision marks on the stainless steel shell of the valve body. If so, replace the valve body.
2 if the valve body does not move, gently tap the valve body part of the valve body. If not, go to the next step.
3 turn the machine on and off repeatedly. In case of heating and cooling equipment, repeat the cooling / heating conversion three times. If the valve body moves after power on, it indicates that impurities are stuck in the system. If it still does not work, remove the electronic throttle component.
4. Purge the removed electronic throttle elements with clean nitrogen in the positive and negative directions, and then send pulse signals to the monomer to observe whether the valve body acts. If there is no action, return to the factory for further analysis.
After the above steps, the monomer can be re installed and used normally. Before installation, the refrigeration system must be cleaned to prevent impurities from adhering again.