Carrier 42QHF009DS Service Manual page 34

3. Adding the refrigerant if the pipe length >5m
Electronic scale
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
8) Be sure to check the gas leakage.
Brush some bubble water at connections which have been connected during installation especially for the
valve connections
Note:
Be sure to use a torque wrench to tighten the service port cap to a torque 18N.m..
10.5 Adding the refrigerant after running the system for many years
34 / 78