Collecting Refrigerant For Replacing Indoor Unit - Hitachi RPI-0.8FSG1 Service Manual

2.12 Collecting Refrigerant for Replacing Indoor Unit

(1) Prepare an empty refrigerant cylinder at -760mmHg with a charging hose. Measure the empty
cylinder's weight.
(2) After shutting the stop valve on the cylinder, connect the charge hose to the liquid line stop valve.
Connect a pressure gauge to the check joint on the gas line stop valve.
(3) Air purge inside of the hose between the liquid line stop valve and cylinder by loosening connection
of the liquid line stop valve and close the connecting port of the cylinder after air purging.
(4) Operate the unit as cooling mode at a frequency of 48Hz.
Liquid Line
Stop Valve
(5) Open the liquid line stop valve on the cylinder to collect refrigerant into it. The cylinder capacity shall
be equivalent to half of the total refrigerant capacity. Check the refrigerant quantity by measuring the
weight.
(6) Close the liquid line stop valve on the cylinder gradually during the cooling operation.
(7) Fix the opening of the liquid line stop valve at a slightly opened position. Continue the cooling
operation.
(8) Finally close the liquid line stop valve and then gas line stop valve and stop the units at the same
time when the pressure at the liquid line stop valve reaches at -400mmHg.
NOTE:
In the case that the collected refrigerant is recharged into the system, charge it by let the cylinder up
side down so that refrigerant and oil can be charged together.
Hose
Connecting
Port
Cylinder
Pressure Gauge
Gas Line
Stop Valve
(2.12 Collecting Refrigerant for Replacing Indoor Unit)
NOTES:
1. The cylinder capacity shall be equivalent
to half of the total refrigerant capacity.
2. In case of 8HP and 10HP outdoor units;
Remove the terminals of the constant
speed compressor, and cover the
terminals of the cables by insulator.
SERVICING
2-133