Carrier 38QUA009DS, Service Manual, Page: 72 / 116

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After purging the air, use a torque wrench to
tighten the flare nut on the 2-way valve.
4). Check for gas leaks.
Check the flare connections for gas leaks.
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 displays a value between 0.3 to 0.5
Mpa(43.5 to 72.5Psi)
6). Disconnect the charge set and the charging
cylinder. Set the 2-way and 3-way valves to the
open position.
Be sure to use a hexagonal wrench to open and
close 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 of 18N·m.
Be sure to check for gas leaks.
13.4.4 Adding Refrigerant after Long-Term
System Operation
Procedure
1). Connect the charge hose to the 3-way
service port and open the 2-way and 3-way
valve.
Connect the charge hose to the valve at the
bottom of the cylinder. If the refrigerant is
R410A, place 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
and press the check valve on the charge set to
purge the air (be careful of the liquid
refrigerant).
3) Place the charging cylinder onto the
electronic scale and record the weight.
4) Turn on the air conditioner in 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 gauge and the
pressure of the low side), 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 leaks.
13.4.5 Re-installation When Indoor Unit
Requires Repairs
1. Collecting the Refrigerant into the
Outdoor Unit
Procedure
1). Confirm that both the 2-way and 3-way
valves are open.
Remove the valve stem caps and confirm that
the valve stems are open.
Be sure to use a hexagonal wrench to operate
the valve stems.
2). Connect the charge hose with the push pin
of handle lo to the 3-way valves gas service
port.
3). Purge the air from the charge hose.
Open the handle Lo valve of the manifold valve
slightly to purge air from the charge hose for 5
seconds and then close it quickly.
4). Close the 2-way valve.