1. Installation of  the cold room evaporators
1). When choosing the position of the lifting point, first consider the best position for air circulation, and secondly, consider the structural direction of the library body. The clearance between the air cooler and the library board should be greater than the thickness of the cold room evaporators.

2. Group installation of cold room condensing unit
1). The semi-hermetic or hermetic compressor should be equipped with an oil separator, and an appropriate amount of oil should be added to the oil. When the evaporation temperature is lower than -15 degrees, a gas-liquid separator and an appropriate amount of refrigerating oil should be installed.
2). The compressor base should be equipped with a shock-absorbing rubber seat, and there should be maintenance space for the installation of the cold room condensing unit, so that it is easy to observe the adjustment of the instrument and the valve.
3). The diameter of the copper pipe should be selected strictly in accordance with the compressor suction and discharge valve interface. When the cold room condensers and the compressor are separated by more than 3 meters, the pipe diameter should be increased. Keep a distance of more than 400mm between the suction surface of the condenser and the wall, and keep a distance of more than 3 meters between the air outlet and obstacles.
4). The diameter of the inlet and outlet of the liquid storage tank shall be based on the exhaust and liquid outlet pipe diameters marked on the unit sample. The compressor suction pipe and the air cooler return pipe shall not be smaller than the size indicated in the sample to reduce the internal resistance of the evaporation pipe.

3. Fluoride and debugging of refrigeration system
1). Measure the power supply voltage, and measure the resistance of the three windings of the compressor and the insulation of the motor.
2). After pumping out, pour refrigerant into the liquid storage to 70%-80% of the standard charge, and then run the compressor, add air from low pressure to enough, set the temperature according to the frosting and use of the cold storage Parameters and opening degree of expansion valve
3). After starting up, first listen to whether the sound of the compressor is normal, check whether the cold room condensers and cold room condensers are running normally, and whether the three-phase current of the compressor is stable. After normal cooling, check all parts of the refrigeration system, discharge pressure, suction pressure, discharge temperature, suction temperature, motor temperature, crankcase temperature, temperature before the expansion valve, observe the frosting of the evaporator and expansion valve, and observe the oil The oil level and color of the mirror have changed, and whether the sound of the equipment is abnormal.

4, matters needing attention during debugging
1）. Check whether each valve in the refrigeration system is in a normal open state, especially the exhaust shut-off valve, do not close it. Open the cooling water valve of the condenser. If it is an air-cooled condenser, turn on the fan, check the direction of rotation, and the water volume and air volume should meet the requirements.
2）. The electrical control circuit should be tested separately in advance, and attention should be paid to whether the power supply voltage is normal before starting. Whether the oil level of the compressor crankcase is in the normal position, generally should be kept at the horizontal centerline position of the sight glass.

3）. Listen for the sound of refrigerant flowing in the expansion valve, and observe whether there is normal condensation (air conditioning) and frosting (cold storage) in the pipeline behind the expansion valve. The compressor with energy unloading should work at full load at the beginning of operation. This can be based on the temperature of the cylinder head by hand. The temperature of the cylinder head is higher, and the temperature of the cylinder is lower in the working cylinder head. The cylinder is unloaded. When the unloading test is carried out, The motor current should drop significantly.
4）. The safety protection devices installed in the refrigeration system, such as high and low pressure relays, oil pressure differential relays, cooling water and chilled water cut-off relays, chilled water freezing protection relays and safety valves, should be dealt with during the commissioning stage. The action is identified to avoid malfunction or inaction. Check whether the indicated values of various other instruments are within the specified range. If abnormal conditions occur, stop the machine immediately for inspection.

The above information is summarized and compiled by the engineers of KITDOO Refrigeration Company. KITDOO provides customers with professional one-stop cold chain optimization services.