1. The refrigeration compressor cannot start normally
Maintenance ideas
1. First check whether the power supply voltage is too low or the motor circuit is poorly connected. If it is indeed the grid voltage is too low, restart after the grid voltage returns to normal: if the line is in poor contact, the connection between the line and the motor should be detected and repaired.
2. Check whether the exhaust valve plate is leaking: If the exhaust valve plate is damaged or the seal is not tight, the pressure in the crankcase will be too high, resulting in failure to start normally. Replace the exhaust valve plate and sealing line.
3. Check whether the energy regulating mechanism fails. Mainly check whether the oil supply pipeline is blocked, the pressure is too low, the oil piston is stuck, etc., and repair it according to the cause of the failure.
4. Check whether the temperature controller is damaged or out of balance; if it is out of balance, the temperature controller should be adjusted; if it is damaged, it should be repaired or replaced.
5. Check whether the pressure relay fails. Repair the pressure relay and reset the pressure parameters.
2. No oil pressure
Maintenance ideas
1. Check whether there is oil leakage or blockage at the connection of the oil pump pipeline system. The joint should be tightened; if it is blocked, the oil pipeline should be cleared.
2. Whether it is because the oil pressure regulating valve is opened too large or the valve core falls off. If the oil pressure regulating valve is not properly adjusted, adjust the oil pressure regulating valve and adjust the oil pressure to the required value; if the valve core falls off, re-install the valve core and tighten it firmly.
3. If there is too little oil in the crankcase or there is refrigerant, the oil pump will not feed oil. If the oil is too low, it should be refueled in time; if it is the latter, it should be stopped in time to exclude the refrigerant.
4. The oil pump is seriously worn. The gap is too large, causing the oil pressure to not come up. In this case, the oil pump should be repaired, and it should be replaced directly when the fault is serious.
5. Check whether the connecting rod bearing bush, main bearing bush, connecting rod small end bushing and piston pin have been seriously worn. At this time, the relevant parts should be replaced in time.
6. The gasket of the rear end cover of the crankcase is dislocated, which blocks the oil inlet channel of the oil pump. It should be disassembled and checked, and the position of the gasket should be re-fixed.
3. A lot of foam is generated in the crankcase
Maintenance ideas
The foaming of the lubricating oil in the crankcase causes liquid hammer, which is mainly caused by the following two reasons:
1. There is a large amount of refrigerant mixed in the lubricating oil. When the pressure is reduced, the refrigerant will evaporate and produce a lot of foam. For this, the refrigerant in the crankcase should be evacuated.
2. Too much lubricating oil is added to the crankcase, and the large end of the connecting rod stirs the lubricating oil to cause a lot of foam. For this, the excess lubricating oil in the crankcase should be released to make the oil level reach the specified oil level line. .
Fourth, the oil temperature is too high
Maintenance ideas
1. The shaft and the tile are not properly assembled. The gap is too small. The size of the shaft and tile assembly gap should be adjusted to make the gap meet the standard requirements.
2. The lubricating oil contains impurities, causing the bearing bush to be rough. In this regard, the shaved bearing bush should be scraped flat and replaced with new oil: if the tile is severely shaved, a new tile should be replaced.
3. The shaft seal friction ring is installed too tightly or the friction ring is rough. The shaft seal friction ring should be re-adjusted. If the friction ring is seriously bruised, a new friction ring should be replaced.
4. If it is caused by the high temperature of suction and discharge of compression starvation, the liquid supply valve of the system should be adjusted appropriately to make the suction and discharge temperature return to normal.
5. The pressure in the crankcase rises
Maintenance ideas
1. The seal of the piston ring is not tight, resulting in the flow of air from high pressure to low pressure. The new piston seal ring should be replaced.
2. The exhaust valve sheet is not closed tightly, causing the pressure in the crankcase to rise. The tightness of the exhaust valve seat should be checked, and if the seal is not tight, a new valve should be replaced in time.
3. The tightness of the cylinder liner and the machine base is deteriorated: the cylinder liner should be removed, the joint should be cleaned and sealed, and then reassembled.
4. Too much refrigerant enters the crankcase, and the pressure rises after evaporation: as long as the excessive refrigerant in the crankcase is evacuated.
6. Failure of the energy regulating mechanism
Maintenance ideas
1. Check whether the oil pressure is too low or the oil pipe is blocked. If the oil pressure is too low. Adjust and increase the oil pressure; if the oil pipe is blocked, the oil pipe should be cleaned and dredged.
2. Whether the oil piston is stuck: the oil piston should be removed to clean and replace the dirty oil. It can be reassembled correctly.
3. Whether the tie rod and the rotating ring are installed incorrectly, causing the rotating ring to be stuck – focus on checking the assembly of the tie rod and the rotating ring, and repair it until the rotating ring can rotate flexibly.
4. Check whether the oil distribution valve is improperly assembled. If the ventilation method is used to check whether each working position is appropriate, and the oil distribution valve can be readjusted.
7. The heat waste of the return air is too large
Maintenance ideas
1. Check whether the ammonia liquid in the evaporator is too small or the opening degree of the liquid supply valve is too small. If the system is short of ammonia, it should be replenished in time; if the liquid supply valve is not adjusted properly, the liquid supply: valve should be opened to an appropriate position.
2. Whether the insulation layer of the return gas pipeline is poorly insulated or damaged by moisture. Insulation should be thoroughly inspected and replaced with new insulation.
3. The air leakage of the suction valve is broken or damaged: if the air leakage is slight, the valve plate can be ground to make it no longer leak; if it is broken, the new suction valve plate can be replaced directly.
Eight, no oil pressure
Maintenance ideas
1. Check whether there is oil leakage or blockage at the connection of the oil pump pipeline system. The joint should be tightened; if it is blocked, the oil pipeline should be cleared.
2. Whether it is because the oil pressure regulating valve is opened too large or the valve core falls off. If the oil pressure regulating valve is not properly adjusted, adjust the oil pressure regulating valve and adjust the oil pressure to the required value; if the valve core falls off, re-install the valve core and tighten it firmly.
3. If there is too little oil in the crankcase or there is refrigerant, the oil pump will not feed oil. If the oil is too little, it should be refueled in time; if the latter, it should be stopped in time to remove the ammonia liquid.
4. The oil pump is seriously worn. The gap is too large, causing the oil pressure to not come up. In this case, the oil pump should be repaired, and it should be replaced directly when the fault is serious.
5. Check whether the connecting rod bearing bush, main bearing bush, connecting rod small end bushing and piston pin have been seriously worn. At this time, the relevant parts should be replaced in time.
6. The gasket of the rear end cover of the crankcase is dislocated, which blocks the oil inlet channel of the oil pump. It should be disassembled and checked, and the position of the gasket should be re-fixed.
9. The suction pressure of the compressor is lower than the normal evaporation pressure
Maintenance ideas
1. The opening of the liquid supply valve is too small, which can lead to insufficient liquid supply, so the evaporation pressure will drop. In this regard, as long as the liquid supply valve is opened to an appropriate extent.
2. The valve in the suction line is not fully opened or the valve core falls off. If the former, the valve should be fully opened; if the valve core falls off, the valve core should be reinstalled.
3. There is a lack of refrigerant in the system. Even if the pressure valve is opened, the evaporation pressure is still low. At this time, an appropriate amount of refrigerant should be supplemented according to the actual situation.
4. The return air pipe is thin, or there is a “liquid bag” phenomenon in the return air pipe. If the pipe diameter is too small, the appropriate return air pipe should be replaced; if there is a “liquid bag” phenomenon, the air return pipe should be replaced. Remove the “bag” section and re-weld the pipe.
10. Compressor wet stroke
Maintenance ideas
1. When the compressor starts, if the suction valve is opened too fast, it will cause a wet stroke: therefore, the suction valve should be opened slowly when starting up to avoid wet stroke and damage to the compressor.
2. If the opening of the liquid supply valve is too large, it will also cause a wet stroke. At this time, as long as the liquid supply valve is properly closed, it is enough.
3. When the refrigerator returns to normal temperature after defrosting, the suction valve should be opened slowly, and the operation of the refrigeration compressor should be observed at any time. If the return air temperature drops too fast, it should be stopped temporarily, and when the operation returns to normal, it will continue to be turned on slowly.
11. There is a knocking sound in the crankcase
Maintenance ideas
1. Check whether the clearance between the connecting rod big end bush and the axle journal is too large. At this time, the gap should be adjusted, or the new tile should be replaced directly.
2. If the gap between the main bearing and the main journal is too large, collision and friction will occur, resulting in a knocking sound. The tiles should be repaired or replaced with new ones.
3. Check whether the cotter pin is broken and the connecting rod nut is loose. If so, replace the cotter pin with a new one and tighten the connecting rod nut.
4. If the center of the coupling is not correct or the keyway of the coupling is loose. The coupling should be adjusted or the keyway should be repaired or a new key should be replaced.
5. The main bearing steel ball is worn and the bearing frame is broken. In this regard, replace the new bearing.
12. Serious oil leakage of shaft seal
Maintenance ideas
1. Check whether the shaft seal is poorly matched, causing serious oil leakage from the shaft seal. The shaft seal should be assembled correctly.
2. Check whether the friction surface of the moving ring and the fixed ring has been rough. If the pulling is serious, the sealing surface should be carefully ground and reassembled.
3. If the rubber seal garden is aging or the tightness is not properly set, oil will leak: for this, the rubber garden should be replaced with a new one, and the appropriate tightness should be adjusted.
4. Check whether the oil leakage of the shaft seal is caused by the weakening of the elastic force of the shaft seal spring: the original spring should be removed and a new spring of the same size should be replaced.
5. Check whether the sealing performance between the back of the fixing ring and the shaft seal gland is deteriorated. For this, the retaining ring should be removed, and the back ring should be cleaned and reassembled.
6. If the crankcase pressure is too high, it should be adjusted. But before stopping, the pressure of the crankcase should be lowered and the exhaust valve should be checked for leakage.
Thirteen, cylinder wall temperature overheating
Maintenance ideas
1. If the oil pump fails, causing the oil pressure to be too low or the oil circuit to be blocked: it should be stopped for a comprehensive overhaul.
2. Check whether the gap between the piston and the cylinder wall is too small or the piston is deviated: at this time, the piston should be adjusted.
3. The safety block or false cover is not tightly sealed, resulting in high and low pressure gas. Measures should be taken to repair this to improve the sealing performance.
4. Check whether the suction temperature is too high. Adjustments should be made to bring the suction temperature down.
5. If the quality of the lubricating oil is not good, the viscosity is too small. It should be stopped to replace the new lubricating oil.
6. Check whether the scale in the cooling water jacket is too thick or the amount of water is insufficient: if the scale is too thick, it should be removed in time; if the amount of bitter water is insufficient, the amount of cooling water should be increased.
7. Check whether the suction and exhaust valves are damaged. If damaged, the suction and exhaust valve plates should be replaced in time.
8. Check whether the piston ring has been seriously worn. If so, replace the piston with a new one.
Post time: May-25-2022
