1. Why should we control the impurity content and moisture content in compressors and air conditioning systems?
Impurities entering the friction surface of the moving parts in the refrigeration compressor body will cause abnormal scratches and wear. Besides, impurities entering the solenoid valve, expansion valve, control valve, capillary tube and stop valve in the air conditioning system will block the valve hole or make the valve not close tightly and fail.
The moisture in the compressor and air conditioning system will mainly have several adverse effects:
●The capillary tube and expansion valve will be blocked by ice, and the evaporator cooling tube will also freeze;
●Metal materials are corroded and deposits are generated;
●The valve core is corroded and not closed tightly;
● "Copper plating" phenomenon occurs on the surface of the refrigeration compressor body parts;
● Accelerating the deterioration of materials such as insulating materials, refrigerants, and refrigeration oil.
2. What effect will low voltage have on the air conditioning system?
If the voltage is too low, much lower than the specified operating voltage range of the refrigeration compressor, due to the stall, the current value is likely to fail to reach the action current specification of the protector, which will cause the protector to fail to act in time, causing the compressor motor to overheat or even burn.
3. What is the function and working principle of the compressor protector?
The function of the refrigeration compressor protector is mainly to protect the compressor from accidents such as motor burnout when it is in an abnormal situation.
Main working principle: It makes the bimetallic strip move, thereby cutting off the circuit and protecting the compressor from damage through the collective effects of the current passing through the internal heating wire of the protector and the internal resistance of the bimetallic strip to generate heat and the external heat conduction.
4. What basic steps to take after the compressor fails?
Unable to start, no suction and discharge pressure: first check the compressor wiring, pipeline connection, main and auxiliary coil impedance, compressor dielectric voltage withstand test and other basic items. If everything is normal, it is recommended to remove the compressor for idling to detect whether there is suction and discharge gas.
Method to detect whether there is the suction and discharge gas: when the compressor is running, press the finger on the discharge port for a few seconds, then remove your hand, and observe whether there is gas spraying. It is normal for a small amount of oil to spray out. If there is suction and discharge gas, and the discharge pressure is large, it means that the compressor can work normally, otherwise the compressor is abnormal.
5. Why is it forbidden for liquid refrigerant to flow back into the compressor suction chamber?
During the rotation of the crankshaft, the volume of the compressor becomes smaller and smaller and the pressure rises sharply. At this time if liquid refrigerant directly enters the suction chamber of the refrigeration compressor, it will cause abnormal stress on the compressor body parts and valve plates or even damage. Liquid slugging will also cause abnormal vibration and noise of the compressor.
In addition, after the liquid refrigerant enters the compressor chamber, it will "wash away" the lubricating oil on the surface of parts such as the piston and blades, resulting in a situation equivalent to "oil-deficient operation", abnormal wear and even causing the compressor to seize the shaft.
6. What are the effects of the wrong wiring of the compressor? Why can not the protector function?
If the compressor is connected incorrectly, it will not work properly. Depending on the different wiring errors, it may cause stalling, reversing rotation, and stop after starting, etc., and it is very likely to cause the compressor motor to burn directly.
Since the compressor protector is selected based on the working characteristics of the protector under abnormal working conditions when the compressor is correctly wired, it is impossible to ensure that the compressor is protected when it is connected incorrectly. In the case of miswiring, it is difficult to protect the compressor motor through the protector.
7. For the same system, does it need to adjust the system when changing compressors from different manufacturers?
The performance characteristics of refrigeration compressors produced by different manufacturers are different. For a specific compressor, the best performance will only be shown under specific refrigerant flow, suction and discharge pressure, temperature and other conditions.
Therefore, on the same air-conditioning system, when using different compressors, it is best to adjust the system separately to ensure that the compressor used works normally under the appropriate refrigerant flow, suction and discharge pressure and temperature conditions, so as to effectively extend the service life of the compressor and achieve the best use effect.
8. Why is there a requirement for the temperature of the compressor motor coil during operation?
This is determined by the insulation classes (A (105°C), E (120°C), B (130°C), F (155 °C), H (175°C)) and heat resistance of the insulation material used in the compressor motor. For the motor enameled wire, too high a temperature will greatly reduce its service life.
In addition, too high a motor temperature can cause excessive dissolution of polymers in the insulation material, which will precipitate and collect somewhere in the system or at the compressor discharge port, thereby affecting the performance of the compressor and the system. Besides, too high a coil temperature will cause the compressor motor efficiency to decrease.
