How to analyze the causes and solutions of compressor failures

Cause Analysis of Air Conditioning Compressor Failure

1.1 There is a problem with the installation process

The air-conditioning system has a variety of components, all of which work together to ensure the normal operation of the air-conditioning system. Professional air conditioner manufacturers will carefully clean the Freon system pipes in the process of producing air conditioners, and clean the dust on the pipe walls by purging. After the purging work is completed, the staff will continue to use a white silk cloth to Wipe clean until the inside of the copper pipe is free of any dirt. Therefore, the staff needs to clean the air-conditioning equipment and clean all the parts inside the compressor. However, because the interior of the unit belonged to the peak working period at that time, the internal acid substances accumulated for a long time, which eventually caused the compressor to be damaged.

1.2. Installation under high temperature and high-pressure environment

Under the action of high temperature, the adhesion of lubricating oil is greatly reduced, and a complete oil film cannot be formed in the extruded part. The long-term operation will cause the compressor to be stuck, and due to insufficient lubrication, the compressor needs to overcome high friction. It can work normally, and the working current increases linearly, which accelerates the corrosion of the enameled wire sheath by acid substances. The increase in the condensing temperature leads to an increase in the power consumption of the equipment, but the cooling capacity of the air conditioner continues to decrease.

1.3 Maintenance problems

First, there is moisture inside the system. Freon and water dissolve each other and eventually generate acidic substances, which will seriously corrode the enameled wire sheath inside the equipment. Only 0.05% of the moisture in R12 will cause copper plating on the steel parts of the compressor. As a result, the piston, bearing, suction valve plate, and valve port of the compressor will form a serious copper plating phenomenon. As the temperature rises, the moisture inside the equipment will increase, and the copper plating will become more and more serious. Over time, it will lead to valve sealing problems, and may even seriously reduce the refrigeration capacity of the compressor, resulting in damage to the internal components of the air conditioner.

The basic method of fault diagnosis of compressor

1. Single-phase power supply cannot be started

a. Check whether the electrical connection is correct and whether it is loose;

b. Check whether the voltage between the terminals is normal, and use a multimeter to measure the resistance of CR and cs between the terminals of the terminals (the common fault is that the main and auxiliary windings are anchored, causing the auxiliary winding to burn out and the resistance value to drop; when the built-in overload protector acts, it is Infinity; when the temperature is high, the resistance value will rise);

c. Check whether the running capacitor is damaged;

d. When an external overload protector is installed, use a multimeter to measure whether the overload protector is turned on;

e. The inverter should pay special attention to the failure of the electric control.

2. The three-phase power supply cannot be started

Check whether the resistance between the terminals is normal. Use a multimeter to measure the resistance between the terminals T1, T2, and T3. When it is normal, the three resistance values should be the same (abnormality is a short circuit, open circuit, or abnormal resistance value; when the overload protector acts, the resistance value should be the same. is infinite; when the temperature is high, the resistance value will rise).

3. Boot one without compression

a. With or without charging refrigerant

b. Whether other refrigeration accessories such as four-way valves are normal;

c. Check whether the suction port is blocked by welding, let off the refrigerant, open the suction and exhaust ports, start the compressor directly, and observe whether the suction and exhaust are normal (be careful not to take too long)

d. It is absolutely forbidden to run in the air. If it is confirmed that the compressor wiring/power supply/capacitor is OK, but it still cannot be started, take the compressor off the assembly line, seal the suction and exhaust ports, etc., return to the warehouse, and hand it over to the compressor factory for processing;

e. Three-phase power supply, the reverse phase of the power supply will cause the compressor to reverse.

4. There is abnormal sound, the noise is loud

a. When the compressor starts, within 3 to 5 minutes, due to the instability of the system, the sound will be too loud;

b. Whether it is the sound of pipeline vibration, wind blade sound, rice gold vibration sound

c. When air is mixed in the system, there will be airflow sound;

d. When there are impurities or copper chips in the system, the sound of metal hitting the valve plate will occur;

e. When the sound is much higher than normal or there is continuous abnormal sound, it can be judged that the compressor is not qualified.

5. Breakdown

a. There are water droplets, impurities at the bottom of the terminal, and impurities in the protective layer of the square. Wipe the water droplets or impurities;

b. There is oxide skin inside the compressor. With the terminals, the refrigerant can be released to flush out impurities, and then the pressure resistance test of the compressor can be carried out separately;

c. After the compressor is charged with refrigerant, the insulation resistance value between the casing and the terminals may decrease to about 2MQ (normal withstand voltage), so please be careful not to use the usual 20MQ standard to measure at this time:

d. The compressor is burnt, please replace the compressor

6. Too much power

a. Whether other components of the system (mainly motors and electronic controls) work normally;

b. Whether the refrigerant charge is normal;

c. Whether the system is likely to be blocked, resulting in high pressure and low low pressure

How to Prevent Air Compressor Damage

(1) Regular cleaning of the air-cooled condenser: After the air-cooled condenser is properly cleaned, the overall operation of the air conditioner is better, and the cooling capacity is significantly improved.

(2) Clean the freon pipes inside the air-conditioning equipment every once in a while: replace the lubricating oil of the equipment and the filter element of the drying filter from time to time, only in this way can the interior of the air-conditioning equipment be kept clean enough and get rid of related failure problems.

(3) Regularly or irregularly check the resistance value of the equipment compressor.