Panasonic U-72MF2U9 Service Manual page 73

4. Recovering Refrigerant
4. Recovering Refrigerant
4-2-1. Cooling operation (for all units)
(1) If the remote controller is used for maintenance of the outdoor unit
1. Connect the outdoor unit maintenance remote controller to the RC connector (3P) (BLU) (CN73) on any
one of the outdoor unit control PCBs. Then start a test run of all units. (Press and hold the
button for 4 seconds or longer.)
2. Press the
See the Section 3 for the detail of the outdoor maintenance remote controller operation.
It may be possible to determine whether operation is cooling or heating by touching the suction tube or
discharge tube.
Cooling : low temperature (68 °F (20 °C) or lower)
Heating : high temperature (140 °F (60 °C) or higher)
CAUTION
(2) If the remote controller is not available for maintenance of the outdoor unit.
1. Determine the outdoor unit where the unit No. setting (SW5) (3P DIP switch) (Blue) on the outdoor unit
control PCB is set to No. 1.
2. Short-circuit the MODE pin ("COOL" side of CN40) on the main outdoor unit control PCB.
3. Short-circuit the CHK pin (CN23) on the PCB to start test run operation.
4-2-2. Refrigerant recovery procedures (1) (using indoor unit ball valve)
(1) If a ball valve with a service port has been provided in the indoor unit as shown in Fig. 4, follow the instructions
given in (2) through (7) below. If the service port is instead located in the outdoor side, follow the instructions in
"4-2-3. Refrigerant recovery procedures (2)".
(2) Close the discharge tube ball valve.
(3) After running the unit in Cooling mode for about 5 minutes as described in "4-2-1. Cooling operation (for all
units)", fully close the liquid tube ball valve.
(4) Run the unit in Cooling mode for 10 to 20 minutes more.
(5) Fully close the suction tube ball valve, and stop the operation of all units.
(6) Use hoses to connect the manifold gauge valves, refrigerant recovery unit, and refrigerant recovery cylinder
with each other. (Fig. 4) Do each connection quickly to prevent air from entering the tube.
CAUTION
(7) Recover the remaining refrigerant from the
indoor unit using the refrigerant recovery unit.
NOTE
To determine completion of refrigerant
recovery, follow the instructions that
came with the refrigerant recovery unit.
(MODE) button and change to cooling operation and ensure that the cooling is performed.
The discharge tube becomes hot (140 °F (60 °C) or higher) in heating mode.
Be careful so as not to be burnt when touching the tube.
Remaining refrigerant may create internal pressure, therefore care should be taken
when connecting the hoses.
Ball valve (separately purchased)
Refrigerant recovery cylinder
Outdoor Unit Repair Procedures
Outdoor Unit Repair Procedures
Suction tube
Outdoor
Discharge tube
unit
side
Liquid tube
Manifold
gauge
Refrigerant
recovery
unit
2 - 9
2WAY VRF SYSTEM
3WAY VRF SYSTEM
(CHECK)
Service port
Solenoid Solenoid
valve kit valve kit
Indoor uni
t
Fig. 4
1
2
3
4
5
6
7
8
9