2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
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7. Charging Compressor Oil
2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
7. Charging Compressor Oil
7-1. If Refrigerant Has Already Been Charged to Outdoor Unit
Fig. 9
Lo
Hi
Manifold
gauge
Be sure to use an exclusive oil-charging tank for charging compressor oil. Prior to charging, carry out vacuum drying
inside the tank and take care that no air (in the form of bubbles) is permitted to enter the tank.
The oil charging procedures are given below.
* The receiver tank used for maintenance may be used as an exclusive oil-charging tank.
When installing the oil-charging
tank to the refrigerant system to
serve as a safety bypass circuit for
refrigerant, connect it to the gas
tube service port carefully to
avoid releasing refrigerant into the
atmosphere.
(DPR : CV623-081-7937)
Nipple
Packless valve
(Receiver-tank:
CV638-015-2988)
Perform oil charging
work carefully so that no
liquid refrigerant enters
the charging tank.
CAUTION
(1) Evacuation drying in oil-charging tank
With the lower side valve fully closed, open the upper side valve and connect it to the vacuum pump via the
manifold gauge valves as shown below. Run the vacuum pump and evacuate the tank until the pressure falls to
below –14.7 psig { -101 kPa, 5 Torr } for the evacuation drying. After the evacuation drying is finished, fully
close the upper valve. Next, fully close the manifold gauge valves and stop the vacuum pump.
To ensure proper evacuation, refer to the operating instructions
that came with the vacuum pump.
CAUTION
Open Close
Upper side
valve
Lower side
valve
Close
Fig. 8
Vacuum pump
Lo
Hi
Manifold
gauge
High-pressure outlet port
(for ø5/16” (ø7.94mm)-
dia connector)
Type: 72, 96
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)
2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
7. Charging Compressor Oil
(2) Charging compressor oil into oil-charging tank
Connect a piece of pipe to the lower valve and then insert the other end deeply into the bottom of the oil con-
tainer. Make sure you avoid letting any air be sucked into the tube. Next, run the vacuum pump and open the
manifold gauge valves, then open the upper and lower valves to begin charging oil into the charging tank.
When the predetermined amount of oil has been charged into the oil-charging tank, immediately close the lower
valve. Next, run the vacuum pump until the system pressure reaches lower than -14.7 psig { -101 kPa, 5 Torr }.
Close the upper valve and then, stop the vacuum pump.
Do this operation quickly because compressor oil easily absorbs moisture from
the air.
(3) Charging compressor oil into outdoor unit
Connect the lower valve to the low-pressure outlet (with Schrader-type push-to-release valve) in the outdoor
unit to be oil-charged, and then connect the high-pressure outlet (with push-to-release valve) to the upper valve
via the manifold gauge valves (at Hi-pressure gauge side). In addition, connect the gas tube service port (with
push-to-release valve) to the DPR (Discharge Pressure Regulator). Carry out the connection work quickly to
avoid letting air enter.
•
•
The hoses may be subject to internal pressure from the refrigerant inside the outdoor
unit. A Schrader-type push-to-release valve is provided at each connection port.
Since the DPR valve opens at pressures of 362.6 psi (2.5 MPa) and above, be sure to
connect the DPR to the gas tube service port (low-pressure side).
Fig. 10
Fig. 11-a
Close → Open
Close → Open
Close
Close
Upper side
valve
Lower side
valve
Lower side
valve
Vacuum pump
CAUTION
CAUTION
Lo
Hi
Manifold
gauge
Upper side
valve
DPR
SM830237-07_北米向け2WAY_VRF.indb 16
18/06/18 18:48:14