First. Four-way valve
The four-way valve is a main component of the outdoor unit of the cold and warm air conditioner, also called the reversing valve, which mainly plays the role of reversing. So how to judge the quality of four-way valve?
Diagnosis method of cross gas-"touch": whether in cooling or heating mode, cross gas means that the cold suction pipe is not cold and the hot exhaust pipe is not hot. The temperature difference between air intake (5~15℃ in rated refrigeration mode) and air exhaust (60~90℃ in rated refrigeration mode) can be measured by temperature testing instrument. If the error is not obvious, the four-way valve is leaking gas, and if there is no temperature measuring instrument, it can be judged by "touching" with hands.
Diagnosis method of stuck-"Listen": When working, turn the coil slightly and listen to whether there is "squeak" electromagnetic noise, which indicates that there is basically no problem with the electromagnetic coil. If there is no obvious "bam" sound when reversing, it indicates that the four-way valve may be stuck. You can tap gently with a small wooden stick to see if you can recover.
Coil diagnosis method-"measurement": Generally, the power supply voltage of the electromagnetic coil of the four-way valve is AC 220V power supply. You can first measure whether the voltage at both ends of the coil is normal, and then use the multimeter to check whether the resistance of the electromagnetic coil is normal.
Case: The four-way valve of a certain brand air conditioner does not change direction when cooling or heating, resulting in poor cooling or heating effect. When you feel the temperature of each tube of the four-way valve by hand, there is little difference in the temperature of the following three tubes.
Cause analysis:
The valve block is stuck, and the machining accuracy of the valve block is not enough; There are foreign objects in the valve body.
The coil is short-circuited, and the coil or lead of the four-way valve is disconnected.
The substrate is small and good, and the external machine substrate has no 220V output.
Capillary blockage.
Second, electronic expansion valve
Electronic expansion valve: it is a throttling element that can enter the refrigerant flow of the refrigeration device according to the preset program. Compared with the traditional throttling elements (capillary tube and thermal expansion valve), the electronic expansion valve has a wider adjustment range, quick and sensitive action, precise adjustment, stability and reliability.
Normal electronic expansion valve: there is a "click" sound after plugging in. If there is no noise, or the expansion valve begins to frost after the compressor works during refrigeration, check whether its coil and power supply are normal (12V pulse electricity). If the voltage is normal, it means that the computer board is normal. If there is no sound in the expansion valve at this time, it is a bad expansion valve. At this time, measure the DC resistance of the coil of the electronic expansion valve first. If it is normal, it may be that the internal organs of the valve body are blocked, and high-pressure gas can be used for purging.
In addition, the electronic expansion valve should be reset when power is cut off. At this time, whether there is a problem with the valve needle can be judged by listening to the sound or feeling whether it vibrates. In the shutdown state, the valve core is generally at the maximum opening. At this time, disconnect the coil lead, and then start the operation. If the refrigerant cannot pass at this time, it can be judged that the valve needle is stuck. Under normal circumstances, the two ends of the electronic expansion valve are touched by hand, and the inlet is warm and the outlet is cold.
Case: The evaporator frosted when the internal unit was not turned on (other internal mechanisms in the same system were running cold). Dismantle the internal unit panel, listen to the obvious sound of running water on the evaporator, touch the temperature difference between the steam pipe and the liquid pipe by hand, power off the internal unit and then turn it on. When the coil of the electronic expansion valve is reset, the internal mechanism is turned on cold, and the refrigeration is normal. It is judged that the electronic expansion valve of the internal unit is not closed properly and there is steam leakage.
Third, the solenoid valve
Solenoid valve is a very important part in refrigeration equipment such as cold storage, air conditioner and water heater. The main function of solenoid valve in refrigeration system is to control the on-off of fluid. The common fault is that it can't be opened or closed. What are the common faults of solenoid valve?
Solenoid valve is not powered on: Failure to power on the solenoid valve will cause the system pipeline to be completely stuck and the fluid cannot pass through. How to check whether the solenoid valve is powered on is very simple. You can use the clamp flow meter to check if there is no current in the system and the power cord to see if it is powered on.
Burn-out of solenoid valve coil: When the solenoid valve coil is burned, the spring inside the solenoid valve can't be attracted, and the system can't be accessed. The inspection method is relatively simple. The resistance value of solenoid valve can be checked through the ohm file of multimeter. If it is zero or infinite, the solenoid valve coil is burned. Another method is to check whether the valve body has magnetic attraction through a screwdriver. If there is no magnetic attraction after electrifying, the coil may have been burned. When replacing, only the coil needs to be replaced, and the valve body does not need to be replaced.
The spring of the solenoid valve is stuck: the spring in the solenoid valve is generally made of stainless steel, but the material will be problematic after long-term use. Once it rusts, it may eventually cause the spring to be stuck, and the pipeline system will not be closed tightly.
If the solenoid valve of cold storage is not closed tightly when it is stopped, it is likely to cause liquid hammer when the compressor is started again. If it is a water heater, the pipeline system is not closed tightly, which may lead to the phenomenon that the water tank may overflow. When the solenoid valve has this fault, it is only necessary to replace the valve core, and the valve body does not need to be replaced.
Shanghai KUB Refrigeration Equipment Co., Ltd.
| Address : |
No. 328 on the 4th plant hengyong Road, Jiading District, Shanghai |
| Factory Address : |
No. 328 on the 4th plant hengyong Road, Jiading District, Shanghai |
| Work Time : |
8:30-17:30(Beijing time) |
| Phone : |
86-021 -63184860-17(Work Time)
86--13916495206(Nonworking time)
|
| Fax : |
86-021-53750132 |
| Email : |
lucy@shkubao.com |
Customer Manager
Mr mick Cai
| Phone : |
+86 13588563336 |
| WhatsApp : |
+86 13588563336 |
| Skype : |
kub.mick |
| WeChat : |
CP9301 |
| Email : |
kub02@shkubao.com |
Miss. Mophy Mao
| Phone : |
+86 15001938306 |
| WhatsApp : |
+86 15001938306 |
| WeChat : |
kub-maomao |
| Email : |
kub@shhkubao.cn |
Mr Peter Huang
| Phone : |
+86 15317830025 |
| WhatsApp : |
+86 15317830025 |
| Skype : |
kub-peter |
| WeChat : |
Shkub_01 |
| Email : |
lucy@shkubao.com |
