Huawei NetCol5000-A050 Quick Manual page 19

8.3
Refrigerant Precharging
1. Take off the vacuum pump from the vacuumizing device, and replace the vacuum pump with a
refrigerant cylinder.
2. Slightly open the refrigerant cylinder valve and slightly loosen the connection nut on the
rubber hose. Tighten the nut when cold air escapes out of the nut.
3. Put the refrigerant cylinder upside down on an electronic balance. Set the reading on the
balance to zero.
4. Open all pressure gauge valves and the refrigerant cylinder valve to charge refrigerant.
5. The amount of precharged refrigerant must be greater than or equal to half of the total charge
amount calculated and less than or equal to the total charge amount. If the total refrigerant
amount cannot be fully precharged, charge the remaining amount of refrigerant after startup.
6. After the refrigerant is charged, close all pressure gauge valves and the refrigerant cylinder
valve.
Charge Amount of
Refrigerant
Standard amount (kg)
Charge amount (kg) =
Standard charge amount +
Extra charge amount
Charge amount (kg) =
Standard charge amount +
Extra charge amount
Without a Low Temperature Component
• The pressure gauge on the left is a low-
pressure gauge, and the one on the right
is a high-pressure gauge.
• The needle valve specifications are 7/16-
20UNF.
One-Way Pipe Total
Length (L)
≤ 10 m
10 m ＜ L ≤ 60 m
60 m ＜ L ≤ 100 m
Low-pressure
needle valve
Exhaust pipe
needle valve
Valve Valve
Connection
nut
18
NetCol500-A060
(NetCol500-A120)
10.2
10.2 + (L – 10) x 0.19 35.8 + (L – 10) x 0.19
10.2 + (L – 10) x 0.25 35.8 + (L – 10) x 0.27
1. Leakage test with
nitrogen
2. Vacuumization
3. Refrigerant
precharging
Reducing
valve
Nitrogen
cylinder
NetCol500-A060
(NetCol500-A120) &
Low Temperature
Component
35.8
Vacuum
pump
Refrigerant
cylinder
Electronic
scale