2
- 25
1
2
3
4
5
6
7
8
9
2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
8. Pumping Out Refrigerant from Outdoor Unit
8-2. If Remote Controller is Not Available for maintenance of Outdoor Unit
(1)
(2) Connect the manifold gauge valves at the Lo side to the low-pressure outlet port of the outdoor unit to be
repaired. Also connect the refrigerant recovery cylinder to any one of the normal outdoor units at the liquid tube
service port (Schrader-type push-to-release valve). Perform the connection work quickly so that no air is
allowed to enter. (Fig. 15)
See “3. Backup Operation” and perform backup operation.
(3) Determine the outdoor unit where the unit No. setting (SW5)(3P DIP switch)(BLU) on the outdoor unit control
PCB is set to No.1.
(5) Short-circuit the CHK pin (CN23) to start operation, leave the unit running for a while. Touch the gas tubing
with fingers to determine whether the unit is running in cooling mode.
* Switching of the 4-way valve occurs immediately before operation starts. Therefore it does not change at this
time. (Mode change cannot be judged from the sound.)
(4) Short-circuit the MODE pin (“COOL” side of CN40) on the outdoor unit control PCB of the No. 1 unit.
The hoses may be subject to internal pressure from the refrigerant inside the outdoor
unit. Check that the manifold gauge valves are fully closed beforehand.
A Schrader-type push-to-release valve is provided at each connection port.
* Connecting the refrigerant recovery cylinder is done to prevent pressure from rising excessively during the
backup operation by recovering the refrigerant from the outdoor unit to be repaired.
(Measure the weight of the refrigerant and cylinder itself beforehand and provide sufficient safety measures,
such as installing a high-pressure cutout in the circuit.)
CAUTION
Fig. 15
To indoor unit
Measuring scale
Connect from here to
refrigerant recovery unit
Refrigerant
recovery
cylinder
Faulty outdoor unit
Other outdoor unit
Lo
Hi
Manifold
gauge
High-pressure outlet port
(for ø5/16” (ø7.94mm)-
dia connector)
Low-pressure outlet port
(for ø5/16” (ø7.94m)-
dia connector)
Liquid tube service port
(for ø5/16” (ø7.94mm)-
dia connector)
8. Pumping Out Refrigerant from Outdoor Unit
2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
(6) Close the gas tube and balance tube on the outdoor unit to be repaired. Then slowly close the liquid tube service
valve.
(7) Connect the high-pressure gauge side of the manifold gauge to the high-pressure outlet port on the outdoor
unit to be repaired, and connect the manifold gauge to the refrigerant recovery device. Be sure that no air
enters the tubing at this time.
(8) Open both Hi- and Lo-side valves on the manifold gauge valves, and recover the refrigerant remaining in the
outdoor unit. After that, measure the amount of recovered refrigerant.
* When the low pressure at the outdoor unit to be repaired reaches 72.5 psi (0.5MPa) or below, pull out the SCT
connector (2P) (YEL) (CN65) from the outdoor unit control PCB of that outdoor unit. Then immediately fully close
the gas tube valve on that outdoor unit.
* Pulling out the SCT connector immediately stops all of the outdoor units.
While closing the valves, the rise in discharge temperature or another factor may
cause a protective device to activate, stopping the operation of the outdoor unit.
If this occurs, immediately fully close the gas tube valve on the outdoor unit to be
repaired.
CAUTION
8. Pumping Out Refrigerant from Outdoor Unit
NOTE
To determine the completion of refrigerant recovery, follow the instructions that came with the
refrigerant recovery unit.
SM830237-07_北米向け2WAY_VRF.indb 25
18/06/18 18:48:17