1, Pre operation inspection
The pre startup inspection of refrigeration equipment is a crucial step related to its normal operation, so operators and maintenance personnel should be particularly careful and meticulous when inspecting:
1. Is the power supply within the range of 380V ± 5%.
2. Is the power supply and control switch in the closed position.
3. Are the buttons, switches, and indicator lights on the control cabinet panel intact and functioning properly.
4. Is the controller displaying normally, and is there any malfunction in displaying barcodes or text.
5. Is the oil level of the refrigeration unit at 1/2 of the oil indicator, and what is the oil color.
6. Is the oil temperature of the refrigeration unit within the normal temperature range.
7. Is the high and low pressure of the refrigeration unit balanced.
8. Are there any leaks in the refrigeration unit and system.
9. Check whether the valves on the refrigeration unit and refrigeration system, including the cooling water system, are fully open.
10. Is the liquid supply solenoid valve working properly.
11. Is there any abnormal noise from the evaporator system coil.
12. Are there any oil droplets generated in the condensate of the evaporator.
13. Is there any abnormal noise when manually starting the evaporator fan.
14. Is the direction of the evaporator fan normal.
15. Check if the control panel and various sensors of the refrigeration unit are intact.
16. Confirm whether the various setting data of the refrigeration unit control panel are correct.
17. View user menu history fault records.
18. Check that there are no fault prompts on the control panel display.
19. The compressor motor can be tapped first to see if it can start and if there are any faults such as excessive starting current.
20. It is particularly important to determine whether the direction of the refrigeration compressor is correct, as the compressor cannot be reversed.
2, Inspection of refrigeration auxiliary equipment
The pre startup inspection of refrigeration auxiliary equipment is an important part related to whether the refrigeration equipment can operate normally for a long time, so the operation and maintenance personnel must carefully inspect it:
1. Is there any leakage in the cooling tower water pool.
2. Is there any water in the cooling tower pool and is the water level normal.
3. Whether the cooling tower water heater is broken or detached.
4. Is the water quality of the cooling tower normal.
5. Is there any abnormal noise when manually starting the cooling tower fan.
6. Is the cooling tower fan turning correctly.
7. Is the operating current of the cooling tower fan normal.
8. Is there any water leakage at the root of the cooling water pump and are all valves open.
9. Is there any abnormal noise when manually starting the cooling water pump.
10. Is the direction of the cooling water pump correct.
11. Is the operating current of the cooling water pump normal.
12. Is the instrument of the cooling water pump system damaged.
13. Is there any leakage in the cooling water pump system.
14. If it is an air-cooled condenser, check the direction of rotation, speed, current and voltage of the air-cooled condenser.
3, Refrigeration equipment startup
Before officially starting up, please confirm the above content again:
1. Press the start button of the compressor, and the cooling water pump will start running. Please check whether the operating voltage and starting current of the cooling water pump are normal in a timely manner, and then check whether the inlet and outlet pressures of the cooling water pump are normal. Is the solenoid valve for liquid supply open? R22 liquid is supplied to the evaporator in the system through the thermal expansion valve. After a few seconds, the suction pressure rises to a certain value, and the compressor will make a motion sound. The compressor starts, and its starting current is twice the rated current of the motor, instantly converting to the rated current of the normal compressor motor.
2. When the compressor is running normally, the compressor oil heater stops running and the electric heater indicator light will turn off.
3. After the compressor runs, the coils or air coolers in the warehouse will start running and begin to cool down.
4. When the cooling water temperature reaches 25 ℃, the refrigeration encyclopedia prompts: Check the set temperature here, and the cooling tower fan will automatically start running, forcing air convection to reduce the temperature of the cooling water. At this time, the operator needs to confirm whether the operating voltage, current, and sound of the fan are normal.
5. When the compressor is fully operational, it is necessary to confirm the operating voltage, operating current, and compressor operating sound. Refrigeration Encyclopedia Tip: The fully automatic unit initially operates a compressor. When the cooling capacity of the compressor cannot meet the external energy, the CPU issues an instruction to start the second compressor to achieve dual machine operation.
6. If the machine is a dual head refrigeration compressor unit, one compressor is started at the beginning of operation. When the temperature sensor on the computer board detects that the temperature curve does not cool down, the computer drives the second compressor to start running. When the temperature of the refrigeration system reaches the set requirement, the CPU unloads one compressor to run. When the temperature of the warehouse completely reaches the set temperature, the CPU commands the first compressor to stop working and enter standby mode. When the second operating temperature is higher than the set temperature of the room, the CPU starts the first compressor to start working first.
7. After the compressor system is running normally, the operator needs to confirm the compressor's exhaust pressure, exhaust temperature, return pressure, return temperature, compressor oil pressure, oil temperature, oil level (refrigeration encyclopedia prompt: the oil level cannot be lower than 1/3 of the oil cup), oil color, condenser inlet temperature, and condenser outlet temperature. The above technical indicators must be within the normal range of compressor operation.
8. After the compressor has been running for a period of time, observe the cooling rate of the warehouse temperature. A fast cooling rate in the warehouse indicates that the refrigeration compressor has a large cooling capacity, and the fan stirs the airflow more thoroughly in the warehouse. In addition, check if there is any vibration sound in the lower tray, if there is any abnormal noise from the air cooler, if the fan is turning correctly, and if there is any backflow in the condensate pipe.
9. When the temperature in the warehouse approaches the set value and the refrigeration compressor is running at full load, the system evaporation temperature and the outlet temperature of the fan coil should be checked, as well as the liquid flow situation of the supply liquid indicator.
10. When the refrigeration compressor is used to cool down the warehouse, and the operating cycle of the compressor is switched from one cycle to another, the operator needs to determine the cycle time of the compressor on and off, and it is best to record it.
