1. The names of the components of the refrigeration system:
1. Compressor
2. High pressure gauge
3. High and low voltage control
4. Oil separator
5. Condenser
6. Reservoir
7. Filter
8. Sight glass
9. Solenoid valve
10. Expansion valve
11. Evaporator
12. Gas-liquid separator
13. Low pressure gauge
2.9. Oil pressure protector: ensure that the compressor has enough lubricating oil.
3. The cold storage is not refrigerated or the refrigerating effect is poor:
Check whether the condenser of the refrigerator is dirty. Check whether there is too much frost on the evaporator in the library. Check for refrigerant leakage (smear soapy water on the connection of the pipes, if bubbles are formed, it means refrigerant leakage). And ask professionals to supplement the refrigerant and deal with the leakage. Check whether the seal of the cold storage door is intact and remove it. Check whether the refrigerator in the cold storage is working. Check whether the parameter setting of the computer controller of the cold storage is correct and readjust. Check the controller of the cold storage for failure and replace it. Check whether there is enough clearance for the stacked items in the warehouse and clear it.
3.1. Is there abnormal noise when the machine is running?
Please stop the machine and check whether it is caused by vibration or mechanical failure. There is abnormal noise in the distribution box. This is the sound from the AC contactor. It is due to the partial inflexibility of the moving parts of the contactor. Please come back after power off and press the iron absorber of the contactor to eliminate the abnormal noise.
3.2. The refrigerator starts frequently or does not start for a long time or does not stop after starting for a long time or shuts down when the storage temperature is lower than?
A. Check whether there is any dirt on the condenser. Poor heat dissipation will cause the condensing pressure of the refrigerator to be too high. In order to protect the compressor, the machine will stop running under the action of the pressure controller. After the heat dissipation is good, press the pressure controller. Black reset button, the machine can automatically resume operation. B. The parameter setting of the controller is wrong, just reset it. C. The refrigeration is not good, please refer to Fault 2. D. Temperature control failure. E. Electrical appliances are damaged.
3.3. There is no response from the cold storage distribution box behind the gate, but the three-phase power is normal.
Please check whether the neutral line has 220V voltage. The components of the cold storage (various valves, controllers) have been set, and there are no parts that the user needs to adjust.
3.4. The lighting in the warehouse is not on.
Please check whether the switch is malfunctioning and whether the bulb is damaged. The power supply should be cut off during the inspection, and the waterproof of the lamp should be paid attention to when installing the lampshade.
3.5. When the ambient temperature is too high, after the refrigerator runs for a period of time, the storage temperature does not reach the set value, and the refrigerator stops early?
This is because the condensing pressure of the refrigerator is too high due to the increase of the ambient temperature. In order to protect the compressor from stopping under the action of the pressure controller, after the heat dissipation is good, press the black reset button on the voltage controller, and the machine will automatically reset. resume operation. And check whether the water condenser dissipates heat well. Do not adjust the set value on the pressure controller arbitrarily, otherwise the pressure controller will not be able to protect the refrigerator.
4. Poor cooling effect
Poor cooling effect means that the cold storage can operate normally and cool, but the temperature in the storage does not drop to the set temperature under the specified working conditions. The main reason is:
4.1. Refrigerant leakage
After the refrigerant leaks in the system, the cooling capacity is insufficient, the suction and discharge pressures are low, and the intermittent "squeak" airflow sound much louder than usual can be heard at the expansion valve. There is no frost on the evaporator or a small amount of floating frost on the corner. If the expansion valve hole is increased, the suction pressure will not change much. After the shutdown, the equilibrium pressure in the system is generally lower than the saturation pressure corresponding to the same ambient temperature.
Troubleshooting method: After the refrigerant leaks, do not rush to fill the system with refrigerant, but find the leak point immediately, and fill the refrigerant after repairing. Refrigeration systems using open compressors have more joints and sealing surfaces, and correspondingly more potential leakage points. When overhauling, you must pay attention to the links that are prone to leakage, and use experience to find out whether there are oil leakage, broken pipelines, and loose streets at the main leakage points.
4.2. Too much refrigerant is charged after maintenance
If the amount of refrigerant charged in the repaired refrigeration system exceeds the capacity of the system, the refrigerant will occupy a certain volume of the condenser, reduce the heat dissipation area, reduce the cooling effect, and cause the suction and discharge pressure to be generally higher than the normal pressure. value, the evaporator does not have solid frost, and the temperature in the storage cools down slowly.
Troubleshooting method: According to the operating procedures, the excess refrigerant must be released at the high-pressure stop valve after a few minutes of shutdown, and the residual air in the system can also be released at this time.
4.3. There is air in the refrigeration system
The air in the refrigeration system will reduce the refrigeration efficiency. The prominent phenomenon is that the suction and exhaust pressure increase (but the exhaust pressure has not exceeded the rated value), and the temperature between the outlet of the compressor and the inlet of the condenser increases significantly. Air, exhaust pressure, and exhaust temperature all rise.
Troubleshooting method: You can release air from the high-pressure shut-off valve several times in a row after a few minutes after shutdown, and you can also properly charge some refrigerant according to the actual situation.
4.4. Low compressor efficiency
The low efficiency of refrigeration compressors means that under the condition of constant working conditions, the actual displacement decreases, resulting in a corresponding decrease in cooling capacity. This phenomenon often occurs on compressors that have been used for a long time. The wear and tear is large, the fitting clearance of each component is large, and the sealing performance of the air valve is reduced, resulting in a decrease in the actual displacement.
Judgment method: close the suction shut-off valve and let the compressor run for a few minutes, discharge the refrigerant in the crankcase into the condenser, stop the machine and immediately close the exhaust valve, and install high-pressure compressors in the bypass holes of the suction and exhaust shut-off valves. , low pressure gauge, turn on the machine again, unscrew the connection of the bypass hole of the suction stop valve, let the air slowly inhale the compressor, so that the pressure in the discharge chamber of the compressor rises slowly, and the pressure rises to 1.MPa, then tighten it The buckle stops sucking in air and lets the compressor continue to run for a few minutes to stop, and then stop for 10 minutes to see how the low-pressure vacuum rises. If the high and low pressures are balanced within 10 minutes, it means that the valve plate has serious leakage.
Remedy: (1) Check whether the cylinder head paper gasket is broken down and cause leakage, and replace it if any. (2) Check whether the high and low pressure exhaust valves are not tightly closed, and replace them if they are found. (3) Check the matching gap between the piston and the cylinder, and replace it if the gap is too large.
4.5. Too thick frost on the surface of the evaporator
The cold storage evaporator that has been used for a long time should defrost regularly. If it does not defrost, the frost layer on the evaporator pipeline will accumulate thicker and thicker. When the entire pipeline is wrapped into a transparent ice layer, it will seriously affect the heat transfer and cause the temperature inside the storage falls below the required range.
Troubleshooting method: Shut down to defrost, open the warehouse door to let the air circulate, or use a fan to speed up the circulation and shorten the defrost time. Do not hit the frost layer with irons, wooden sticks, etc., so as not to damage the evaporator pipeline.
4.6. There is refrigerated oil in the evaporator pipeline
During the refrigeration cycle, some refrigerated oil remains in the evaporator pipeline. After a long period of use, when there is a lot of residual oil in the evaporator, it will seriously affect its heat transfer effect and cause poor refrigeration.
Judgment method: (1) Check whether there is less refrigerant oil in the crankcase of the compressor than before or open the expansion valve to observe the oil in the refrigerant. (2) Judging from the frosting of the evaporator, if the hoarfrost on the evaporator is sparse and incomplete, and no other faults are found at this time, it can be concluded that the cooling effect is poor due to oil.
Remedy: Clear the refrigerant oil in the evaporator. Remove the evaporator, blow it out and then dry it. If it is not easy to disassemble, you can use a compressor to inflate it from the evaporator inlet, and then dry it with a blowtorch.
4.7. Refrigeration system is not smooth
Because the refrigeration system is not clean, after a certain period of use, the dirt gradually accumulates in the filter, and some meshes are blocked, resulting in a decrease in the refrigerant flow rate and affecting the cooling effect. In the system, the expansion valve and the filter screen at the suction port of the compressor are also slightly blocked.
Judgment method: The exhaust pressure is low, the exhaust temperature drops, the temperature of the blocked part is lower than normal, and frost condensation will occur when the blockage is serious.
Remedy: Remove the micro-blocking parts, clean them, dry them, and then install them.
5. The small refrigerator does not cool
5.1. All the refrigerant in the system leaks,
There are two reasons for refrigerant leakage:
Slow leakage: It is not used for a period of time, and the leakage is discovered when it is used, or it is found that it is gradually not cold during use, and finally no cooling.
Rapid leakage: due to the sudden rupture of the system pipeline, the refrigerant leaks out quickly.
Judgment method: The compressor starts easily (when the compressor parts are not damaged), the suction pressure is vacuum-like, the discharge pressure is very low, the discharge pipe is cool, and the sound of liquid flow in the evaporator cannot be heard.
Remedy: Check the whole machine, mainly the parts that are prone to leakage. After the leak is found, it can be repaired according to the specific situation, and finally vacuumized and filled with refrigerant.
5.2. The refrigeration system is blocked;
Expansion valve hole freezing
Failure analysis: (1) Improper drying of main components in the refrigeration system; (2) Incomplete vacuuming of the entire system; (3) Exceeding the moisture content of the refrigerant.
Judgment method: Intermittent refrigeration: The refrigeration is normal at the beginning, and after a period of time, the entire surface of the expansion valve begins to frost, and the evaporation temperature reaches below 0 degrees, and moisture gathers at the expansion valve hole, gradually blocking the valve hole. Then there is frost at the evaporator, and the sound of air flow is not heard, and the suction pressure is in a vacuum state. Heating the expansion valve with hot water will melt the ice layer at the valve hole and allow normal cooling.
Drain method: put a filter with moisture absorbing agent (silica gel, anhydrous calcium chloride) in series in the refrigeration system, filter out the moisture in the system, and then remove the filter.
The expansion valve filter is dirty and clogged
Fault analysis: When there is a lot of coarse powdery dirt in the system, the entire filter will be blocked, and the refrigerant cannot pass through, resulting in no refrigeration.
Judgment method: Tap the expansion valve, and sometimes refrigeration can be achieved through some refrigerant.
Exhaust method: Remove the filter, clean it, dry it, and reinstall it into the system.
clogged filter
Fault analysis: The desiccant has been used for a long time and becomes a paste to seal the filter or dirt gradually accumulates in the filter to cause blockage.
Judgment method: Ventilation will occur after tapping the filter, and the filter is cooler than usual when touched by hand.
Exhaust method: Remove the filter, wash it, dry it, replace the desiccant, and put it into the system.
5.3. Leakage of refrigerant in the temperature sensing bag of the expansion valve
Fault analysis: After the temperature-sensing agent in the temperature-sensing package of the expansion valve leaks, the two forces below the diaphragm push the diaphragm to move upward, which means the valve hole is closed, and the refrigerant in the system cannot pass through, resulting in no refrigeration. At this time, the expansion valve does not frost. , the low pressure is vacuum, and the sound of air flow cannot be heard in the evaporator.
Judgment method: (1) Unscrew the inlet of the expansion valve to see if there is refrigerant spraying out, if yes, close it quickly. (2) Open the expansion valve port to see if there is refrigerant spraying out, if there is no refrigerant, it means it is blocked.
Exhaust method: stop the machine and close the shut-off valve, remove the expansion valve to check whether the filter screen is blocked, if not, blow the inlet of the expansion valve with your mouth to see if it is ventilated. It can also be visually inspected or disassembled for inspection, and replaced if damaged.
Too much refrigerant in the system
Failure analysis: Too much refrigerant causes the exhaust pressure to rise significantly, exceeding the normal value.
Discharging method: stop the machine, and discharge excess refrigerant from the system through the high-pressure exhaust hole.
There is residual air in the system
Fault analysis: There is air circulation in the system, the exhaust pressure is too high, the exhaust temperature is high, the exhaust pipe is hot, the cooling effect is poor, the compressor runs for a short time, the exhaust pressure exceeds the normal value, and the pressure relay is forced to operate.
Exhaust method: Stop the machine and release air at the exhaust valve hole.
Shutdown due to low suction pressure
Fault analysis: When the suction pressure in the system is lower than the setting value of the pressure relay, it will get an electric shock and cut off the power supply.
Discharge method: 1. Refrigerant leakage. 2. The system is blocked.
5.4: The compressor stops suddenly during operation
Shutdown caused by excessive exhaust pressure. (The cooling effect of the condenser is poor)
Fault analysis: Cold storage with air-cooled condenser (1) The fan is not turned on (2) The fan motor is damaged (3) The fan is reversed (4) The ambient temperature is high (up to 40 degrees or more) (5) The heat sink of the condenser is damaged Oil and dust block the air flow.
The motor is overloaded.
Fault analysis: 1. When using, put too much food in the warehouse; 2. The power supply is abnormal.
Discharge method: reduce heat load, pay attention to changes in power supply voltage.
An electrical failure caused a shutdown.
Fault analysis: The thermostat is out of adjustment or the temperature sensing package is improperly installed.
Exhaust method: Remove the thermostat to overhaul its electric shock, adjust, and adjust the position of the temperature sensor.
(4) Sudden shutdown caused by other reasons.
Fault analysis: In the process of use and maintenance, it is often necessary to open and close the shut-off valves such as exhaust, suction, and liquid storage. Sometimes the shut-off valve is opened due to negligence, causing the exhaust pressure to rise suddenly.
Discharge method: Stop immediately to prevent danger.
Normal shutdown: When the temperature in the library reaches the set value, the thermostat will automatically shut down.
(2) Check whether the high and low pressure exhaust valves are not tightly closed, and replace them if they are found. (3) Check the matching gap between the piston and the cylinder, and replace it if the gap is too large.
4.5. Too thick frost on the surface of the evaporator
The cold storage evaporator that has been used for a long time should defrost regularly. If it does not defrost, the frost layer on the evaporator pipeline will accumulate thicker and thicker. When the entire pipeline is wrapped into a transparent ice layer, it will seriously affect the heat transfer and cause the temperature inside the storage falls below the required range.
Troubleshooting method: Shut down to defrost, open the warehouse door to let the air circulate, or use a fan to speed up the circulation and shorten the defrost time. Do not hit the frost layer with irons, wooden sticks, etc., so as not to damage the evaporator pipeline.
4.6. There is refrigerated oil in the evaporator pipeline
During the refrigeration cycle, some refrigerated oil remains in the evaporator pipeline. After a long period of use, when there is a lot of residual oil in the evaporator, it will seriously affect its heat transfer effect and cause poor refrigeration.
Judgment method: (1) Check whether there is less refrigerant oil in the crankcase of the compressor than before or open the expansion valve to observe the oil in the refrigerant. (2) Judging from the frosting of the evaporator, if the hoarfrost on the evaporator is sparse and incomplete, and no other faults are found at this time, it can be concluded that the cooling effect is poor due to oil.
Remedy: Clear the refrigerant oil in the evaporator. Remove the evaporator, blow it out and then dry it. If it is not easy to disassemble, you can use a compressor to inflate it from the evaporator inlet, and then dry it with a blowtorch.
4.7. Refrigeration system is not smooth
Because the refrigeration system is not clean, after a certain period of use, the dirt gradually accumulates in the filter, and some meshes are blocked, resulting in a decrease in the refrigerant flow rate and affecting the cooling effect. In the system, the expansion valve and the filter screen at the suction port of the compressor are also slightly blocked.
Judgment method: The exhaust pressure is low, the exhaust temperature drops, the temperature of the blocked part is lower than normal, and frost condensation will occur when the blockage is serious.
Remedy: Remove the micro-blocking parts, clean them, dry them, and then install them.
5. The small refrigerator does not cool
5.1. All the refrigerant in the system leaks,
There are two reasons for refrigerant leakage:
Slow leakage: It is not used for a period of time, and the leakage is discovered when it is used, or it is found that it is gradually not cold during use, and finally no cooling.
Rapid leakage: due to the sudden rupture of the system pipeline, the refrigerant leaks out quickly.
Judgment method: The compressor starts easily (when the compressor parts are not damaged), the suction pressure is vacuum-like, the discharge pressure is very low, the discharge pipe is cool, and the sound of liquid flow in the evaporator cannot be heard.
Remedy: Check the whole machine, mainly the parts that are prone to leakage. After the leak is found, it can be repaired according to the specific situation, and finally vacuumized and filled with refrigerant.
5.2. The refrigeration system is blocked;
Expansion valve hole freezing
Failure analysis: (1) Improper drying of main components in the refrigeration system; (2) Incomplete vacuuming of the entire system; (3) Exceeding the moisture content of the refrigerant.
Judgment method: Intermittent refrigeration: The refrigeration is normal at the beginning, and after a period of time, the entire surface of the expansion valve begins to frost, and the evaporation temperature reaches below 0 degrees, and moisture gathers at the expansion valve hole, gradually blocking the valve hole. Then there is frost at the evaporator, and the sound of air flow is not heard, and the suction pressure is in a vacuum state. Heating the expansion valve with hot water will melt the ice layer at the valve hole and allow normal cooling.
Drain method: put a filter with moisture absorbing agent (silica gel, anhydrous calcium chloride) in series in the refrigeration system, filter out the moisture in the system, and then remove the filter.
The expansion valve filter is dirty and clogged
Fault analysis: When there is a lot of coarse powdery dirt in the system, the entire filter will be blocked, and the refrigerant cannot pass through, resulting in no refrigeration.
Judgment method: Tap the expansion valve, and sometimes refrigeration can be achieved through some refrigerant.
Exhaust method: Remove the filter, clean it, dry it, and reinstall it into the system.
clogged filter
Fault analysis: The desiccant has been used for a long time and becomes a paste to seal the filter or dirt gradually accumulates in the filter to cause blockage.
Judgment method: Ventilation will occur after tapping the filter, and the filter is cooler than usual when touched by hand.
Exhaust method: Remove the filter, wash it, dry it, replace the desiccant, and put it into the system.
5.3. Leakage of refrigerant in the temperature sensing bag of the expansion valve
Fault analysis: After the temperature-sensing agent in the temperature-sensing package of the expansion valve leaks, the two forces below the diaphragm push the diaphragm to move upward, which means the valve hole is closed, and the refrigerant in the system cannot pass through, resulting in no refrigeration. At this time, the expansion valve does not frost. , the low pressure is vacuum, and the sound of air flow cannot be heard in the evaporator.
Judgment method: (1) Unscrew the inlet of the expansion valve to see if there is refrigerant spraying out, if yes, close it quickly. (2) Open the expansion valve port to see if there is refrigerant spraying out, if there is no refrigerant, it means it is blocked.
Exhaust method: stop the machine and close the shut-off valve, remove the expansion valve to check whether the filter screen is blocked, if not, blow the inlet of the expansion valve with your mouth to see if it is ventilated. It can also be visually inspected or disassembled for inspection, and replaced if damaged.
Too much refrigerant in the system
Failure analysis: Too much refrigerant causes the exhaust pressure to rise significantly, exceeding the normal value.
Discharging method: stop the machine, and discharge excess refrigerant from the system through the high-pressure exhaust hole.
There is residual air in the system
Fault analysis: There is air circulation in the system, the exhaust pressure is too high, the exhaust temperature is high, the exhaust pipe is hot, the cooling effect is poor, the compressor runs for a short time, the exhaust pressure exceeds the normal value, and the pressure relay is forced to operate.
Exhaust method: Stop the machine and release air at the exhaust valve hole.
Shutdown due to low suction pressure
Fault analysis: When the suction pressure in the system is lower than the setting value of the pressure relay, it will get an electric shock and cut off the power supply.
Discharge method: 1. Refrigerant leakage. 2. The system is blocked.
5.4: The compressor stops suddenly during operation
Shutdown caused by excessive exhaust pressure. (The cooling effect of the condenser is poor)
Fault analysis: Cold storage with air-cooled condenser (1) The fan is not turned on (2) The fan motor is damaged (3) The fan is reversed (4) The ambient temperature is high (up to 40 degrees or more) (5) The heat sink of the condenser is damaged Oil and dust block the air flow.
The motor is overloaded.
Fault analysis: 1. When using, put too much food in the warehouse; 2. The power supply is abnormal.
Discharge method: reduce heat load, pay attention to changes in power supply voltage.
An electrical failure caused a shutdown.
Fault analysis: The thermostat is out of adjustment or the temperature sensing package is improperly installed.
Exhaust method: Remove the thermostat to overhaul its electric shock, adjust, and adjust the position of the temperature sensor.
(4) Sudden shutdown caused by other reasons.
Fault analysis: In the process of use and maintenance, it is often necessary to open and close the shut-off valves such as exhaust, suction, and liquid storage. Sometimes the shut-off valve is opened due to negligence, causing the exhaust pressure to rise suddenly.
Discharge method: Stop immediately to prevent danger.
Normal shutdown: When the temperature in the library reaches the set value, the thermostat will automatically shut down.
| 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 |