2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
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4. Recovering Refrigerant
2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
4. Recovering Refrigerant
Type: 120, 144
Fig. 3-b
Lo
Hi
Refrigerant
recovery unit
Manifold
gauge
Refrigerant recovery cylinder
High-pressure outlet port
(for ø5/16” (ø7.94mm)-dia connector)
Low-pressure outlet port
(for ø5/16” (ø7.94mm)-dia connector)
Liquid tube service port
(for ø5/16” (ø7.94mm)-dia connector)
Gas tube service port
(for ø5/16” (ø7.94mm)-dia connector)
4-2. Refrigerant Recovery Procedures (Indoor Unit)
The flowchart below shows the refrigerant recovery procedures you must follow when replacing or repairing the indoor
unit due to trouble in the refrigerant circuit.
*
NO
YES
YES
YES
NO
NO
Service work performed on indoor units is done simultaneously
using the service ports at the liquid tube side and the gas tube
side ball valves. Refer to each section in the “Installation
Instructions” on refrigerant charging, leak checking, and
evacuation procedures.
4-2-1. Cooling operation (for all units)
Ball valve is provided
in the indoor unit
4-2-2. Refrigerant recovery procedures (1)
Turn off all equipment in system
When
replacing or repairing
a faulty unit, let other normal indoor
units run (excluding indoor unit where
refrigerant is
recovered)
Power
can independently be turned off
for indoor unit where refrigerant is
recovered
Change controllable number of indoor units (including
changes in group control and integrated-control settings)
Other indoor units can operate normally
Replace or repair faulty unit
Check for leakage in repaired unit H*
Evacuate air from repaired unit H*
Open ball valve
Ready for normal operation
Change controllable number of indoor units (including
changes in group control and integrated-control settings)
Charge refrigerant in repaired unit H* (Amount of charge
should equal that recovered by refrigerant recovery unit)
Turn off all equipment in system
Check for leakage in repaired unit
Evacuate air from repaired unit
Charge refrigerant in repaired unit
(Amount of charge should equal that
recovered by refrigerant recovery unit)
Ready for operation
Replace or repair faulty unit
4-2-3. Refrigerant
recovery procedures (2)
Modify power to permit
turning off power to
refrigerant-recovered
indoor units independently
Replace or repair faulty unit
Check for leakage in repaired unit H*
Evacuate air in repaired unit H*
Open the ball valve
Ready for normal operation
Charge refrigerant in repaired unit H*
(Amount of charge should equal that
recovered by refrigerant recovery unit)
Figs. 2-a, 2-b,
2-c and 2-d
START
END
END
END
4-2-1. Cooling operation (for all units)
(CHECK)
button for 4 seconds or longer.)
(1) If the remote controller is used for maintenance of the outdoor unit
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 (6) below. If the service port is instead located in the outdoor side, follow the instructions in
“4-2-3. Refrigerant recovery procedures (2).”
(2) 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.
(3) Run the unit in Cooling mode for 10 to 20 minutes more.
(6) Recover the remaining refrigerant from the
indoor unit using the refrigerant recovery unit.
(4) Fully close the gas tube ball valve, and stop the operation of all units.
(5) 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 tubing.
(2) If the remote controller is not available 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
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.
3. Short-circuit the CHK pin (CHK)(CN23) on the PCB to start test run operation.
2. Short-circuit the MODE pin (“COOL” side of CN40) on the main outdoor unit control PCB.
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 gas tubing.
Cooling : low temperature (68 °F (20 °C) or lower)
Heating : high temperature (140 °F (60 °C) or higher)
(MODE) button and change to cooling operation and ensure that the cooling is performed.
The gas tubing becomes hot (140 °F (60 °C) or higher) in heating mode.
Be careful so as not to be burnt when touching the tubing.
CAUTION
Remaining refrigerant may create internal
pressure, therefore care should be taken
when connecting the hoses.
CAUTION
2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
4. Recovering Refrigerant
NOTE
To determine completion of refrigerant
recovery, follow the instructions that
came with the refrigerant recovery unit.
Lo
Hi
Refrigerant
recovery unit
Ball valve
(field supply)
Indoor
unit
Outdoor unit side
M
Ball valve
(field supply)
Service port
Manifold
gauge
Refrigerant recovery cylinder
Gas tube
Liquid tube
M
Fig. 4
SM830237-07_北米向け2WAY_VRF.indb 10
18/06/18 18:48:10
