Common faults and analysis methods of solenoid four-way valve
Determine the four-way valve cross-gas: Start the compressor and reverse the four-way valve, and touch the three pipes E, S, and C of the four-way valve at the same time with your hands. If all three pipes are hot, it proves that the four-way valve is not reversed in place.
The failure of the four-way valve to change direction normally
① The solenoid coil is damaged and the pilot valve does not work;
② The valve slide in the four-way valve is stuck or stuck by dirt (scale, debris, degraded grease) inside the system. Part of the problem can be solved by tapping the four-way valve body with a wooden stick or glue stick;
③The valve body is damaged by external impact (the valve body is concave), causing the slide valve to be unable to change direction, which can be judged from the appearance;
④ Due to the liquid shock inside the system, the valve slide guide frame is broken, the end cover is damaged and deformed, and the direction cannot be changed;
⑤The internal gap of the four-way valve is too large, and the valve seat is slightly burned during welding and the leakage exceeds the standard, causing air leakage, balancing the pressure at both ends of the slide valve, and making it impossible to push the slide valve to change direction;
⑥The system pressure causes the main slide of the four-way valve to break, causing the main slide to be unable to change direction;
⑦ The inner cavity of the pilot valve is dirty and blocked, causing the pilot valve to not work;
⑧Due to system reasons, the main slider is in the middle of the valve body when the machine is turned on, and the pressure difference between the two ends cannot be established when the power is turned on, resulting in the inability to reverse direction. Some of this failure can be solved by tapping the valve body and adding refrigerant;
⑨ The system has slow leakage, less refrigerant, and cannot establish the pressure difference required for reversal;
⑩ There is refrigerant leakage in the valve body, capillary tube or solder joint of the four-way valve. Generally, there is a lot of grease on the surface of the valve body. Apply soapy water on the surface of the valve body. If bubbles are generated, it means there is leakage of refrigerant. If there is leakage of refrigerant in the valve body, capillary tube or capillary tube, If there are bubbles in the welding place, the four-way valve needs to be replaced. If there are bubbles in the expansion of the E, S, C or D pipe, it can be solved by repair welding.
