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2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
7. Charging Compressor Oil
2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
7. Charging Compressor Oil
7-2. If Outdoor Unit Has Not Been Charged with Refrigerant
When a compressor has been replaced or in any other case where the outdoor unit has not been charged with
refrigerant, first charge with refrigerant then follow the instructions in “7-1. If Refrigerant Has Already Been
Charged to Outdoor Unit” and charge with oil.
Or, alternatively, follow the procedure below.
(1) Connect a tube to the oil outlet port on the outdoor unit to be charged with oil. Insert the other end of the tube
into the oil container.
(2) Follow the instructions in “6. Evacuating System,” and apply vacuum to the outdoor unit to be charged with oil.
When this is done, oil is charged into the outdoor unit through the oil outlet port.
(3) When the unit has been charged with the designated amount of oil, stop the vacuum pump.
The oil absorbs moisture readily. This work must be completed quickly.
CAUTION
Lo
Hi
Manifold
gauge
Vacuum pump
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)
Oil
Balance tube service port
(for ø5/16” (ø7.94mm)-
dia connector)
Fig. 13
7-3. If Outdoor Unit Has Not Been Charged with Refrigerant
The rated amount of oil is pre-charged in the compressors as given below:
Model name
Compressor model
Q'ty
Pre-charged amount of oil
gallon
liter
U-72ME2U9
C-9RVN393H0M
1
0.502
1.9
U-96ME2U9
C-9RVN393H0N
1
0.502
1.9
U-120ME2U9
C-9RVN393H0M
2
1
0.502
1.9
C-9RVN393H0M
1
0.502
1.9
U-144ME2U9
C-9RVN393H0M
2
1
0.502
1.9
C-9RVN393H0M
1
0.502
1.9
U-72ME2U94
C-9RVN393H0K
1
0.502
1.9
U-96ME2U94
C-9RVN393H0L
1
0.502
1.9
U-120ME2U94
C-9RVN393H0K
2
1
0.502
1.9
C-9RVN393H0K
1
0.502
1.9
U-144ME2U94
C-9RVN393H0K
2
1
0.502
1.9
C-9RVN393H0K
1
0.502
1.9
When replacing a faulty compressor, be sure to first measure the amount of remaining oil in the compressor.
Charge additional new oil equal to the difference in the remaining oil and the rated amount as listed above.
For example: Type of replaced compressor: C-9RVN393H0M
Remaining oil in the removed compressor: 0.581 gal (2.2 liter)
Additional oil to be charged:
Remaining oil in the removed compressor – rated oil amount
= 0.581 gal - 0.502 gal (= 2.2 liter - 1.9 liter)
=0.079 gal (0.3 liter)
* If the result is a negative amount (remaining oil in the removed compressor is less than the rated amount), it is
not necessary to discharge the extra oil from the system.
For the method used for additional oil charging after compressor replacement, see “7-1. If Refrigerant Has
Already Been Charged to Outdoor Unit”.
Required equipment and tools:Jumper wire with clips, adjustable wrench, set of manifold gauge valves for the
refrigerant R410A, refrigerant recovery unit, pre-purged refrigerant cylinder for
recovery, flat-head screwdriver, and outdoor unit maintenance remote controller.
This work is performed in order to collect the refrigerant from an outdoor unit where repairs (other than compressor
replacement) will be performed into other outdoor units and indoor units, and the refrigerant tubing.
SM830237-07_北米向け2WAY_VRF.indb 21
18/06/18 18:48:15
