17
3). Air purging.
Open the valves on the charging cylinder and the
charge set. Purge the air by loosening the flare
nut on the 2-
way valve approximately 45’ for 3
seconds then closing it for 1 minute; repeat 3
times.
After purging the air, use a torque wrench to
tighten the flare nut on the 2-way valve.
4). Check the gas leakage.
Check the flare connections for gas leakage.
5). Discharge the refrigerant.
Close the valve on the charging cylinder and
discharge the refrigerant by loosening the flare
nut on the 2-
way valve approximately 45’ until the
gauge indicates 0.3 to 0.5 Mpa.
6). Disconnect the charge set and the charging
cylinder, and set the 2-way and 3-way valves to
the open position.
Be sure to use a hexagonal wrench to operate the
valve stems.
7). Mount the valve stems nuts and the service
port cap.
Be sure to use a torque wrench to tighten the
service port cap to a torque 18N
·
m.
Be sure to check the gas leakage.
3. Adding the refrigerant if the pipe
length >5m
Procedure:
1). Connect the charge hose to the charging
cylinder, open the 2-way valve and the 3-way
valve.
Connect
the
charge
hose
which
you
disconnected from the vacuum pump to the
valve at the bottom of the cylinder. If the
refrigerant is R410A, make the cylinder bottom
up to ensure the liquid charge.
2). Purge the air from the charge hose.
Open the valve at the bottom of the cylinder
and press the check valve on the charge set to
purge the air (be careful of the liquid
refrigerant).
3) Put the charging cylinder onto the electronic
scale and record the weight.
4) Operate the air conditioner at the cooling
mode.
5) Open the valves (Low side) on the charge set
and charge the system with liquid refrigerant.
6).When the electronic scale displays the proper
weight (refer to the table), disconnect the charge
hose from the 3-
way valve’s service port
immediately and turn off the air conditioner before
disconnecting the hose.
7). Mount the valve stem caps and the service
port
Use torque wrench to tighten the service port
cap to a torque of 18N.m.
Be sure to check for gas leakage.
5.5 Adding the refrigerant after running
the system for many years
Procedure:
1). Connect the charge hose to the 3-way service
port, open the 2-way valve and the 3-way valve.
Connect the charge hose to the valve at the
bottom of the cylinder. If the refrigerant is
R410A, make the cylinder bottom up to ensure
liquid charge.
2). Purge the air from the charge hose.
Open the valve at the bottom of the cylinder
