Carrier 42QHF009DS Service Manual page 35

Electronic scale
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 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 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
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.
.
35 / 78