Gree CN851W1000, Руководство по обслуживанию

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120
DC Inverter Multi
VRF Service Manual
5.11.3 Vacuum pumping
The steps are as follows:
a. Expel the nitrogen after leakage detection;
Connect the pressure gauge to Freon nozzle on outdoor liquid valve and gas valve, and connect a vacuum pump.
Then, establish vacuum simultaneously from high pressure side and low pressure side.
Connector on liquid side
Pressure gauge connector valve
Connector on gas side
Vacuum pump
Start the vacuum pump and turn on “LO” and “HI” knobs;
b. Continue for 0.5~1.0 hour after the vacuum level reaches -0.1MPa (gauge pressure -1kgf/cm2). Then, close the
“VH” knob on high pressure end and “VL” knob on low pressure end to stop the vacuum pump.
c. Remove the hose connected to vacuum pump and reconnect it to the refrigerant tank. Expel the air in the hose.
Open the “VL” knob on low pressure end to charge refrigerant to the system piping. When the pressure reaches 0.0kgf/
cm2, close the “VL” knob on low pressure end.
d. Remove the hose connected to refrigerant tank and reconnect it to vacuum pump. Start the vacuum pump and open
the “VH” knob on high pressure end. Pump for 30 minutes from high pressure end and then open the “VL” knob to pump
from low pressure end, until the vacuum level reaches -0.1MPa (gauge pressure -1kgf/cm2).
If the vacuum level reaches -0.1MPa (gauge pressure) or lower, the vacuuming process is then ended. Stop the
vacuum pump and place still for 1 hour. Then, check the vacuum level for any change. In case of any change, it indicates
that there is leakage. In this case, proceed to leakage detection and repair.
e. When the procedures for vacuum pumping are finished, refrigerant shall be charged.
5�12 Refrigerant Charge
5.12.1 Calculation method for refrigerant charging
Refrigerant shall be charged according to calculated amount specified in engineering drawings.
Method for calculation of added refrigerant volume (based on liquid pipe)
Mass of refrigerant to be charged =∑ length of liquid pipe × refrigerant charge amount of every meter of liquid pipe.
Amount of refrigerant charge for every meter of liquid pipe(kg/m)
Φ22.2 Φ19.05 Φ15.9 Φ12.7 Φ9.52 Φ6.35
0.35 0.25 0.17 0.11 0.054 0.022
Note:
a� Standard pipe length is 15m� If refrigerant piping (L) is shorter than or equal to 15m, no additional refrigerant
is needed If piping is longer than 15m (based on liquid pipe), more refrigerant shall be added� The above table
shows how much refrigerant shall be charged for every one additional meter of piping�
b. Electronic balance shall be used for refrigerant charge.
c. Thickness of pipe wall shall be 0.5~1.0mm and pressure-bearing capability shall be 3.0MPa.
d. The longer the piping, the more refrigerating capacity and heating capacity shall be weakened.