2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
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2. Discharging Compressor Oil
2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
2. Discharging Compressor Oil
Recover the refrigerant in the outdoor unit following the procedures in “4. Recovering Refrigerant.” Remove the
compressor and discharge the oil in it. See “9. Compressor” for detailed procedures.
2-2. Discharging Oil in Compressor
Acceptance/rejection criteria for the oil
2-3. Checking the Oil
It is difficult to measure the total acid value in the field, therefore oil hue and odor are the rule of thumb.
Checking for carbon deposits and abrasive metal powder can additionally be used to assess the system condition.
Judgment criteria for changing oil*
Condition of
refrigeration cycle
Color
Odor
Total acid value
Hue
Normal
Yellowish
None
0.02 or less
3.5 or less
0.06 or over
4.0 or over
Abnormal overheat-
operation
Brownish
Smells somewhat
(not as strong as below)
Changing the oil and system cleaning
with dry-cores are necessary.
Motor burnout
Brownish /
blackish
Pungent / burnt odor
Changing the oil and system cleaning
with dry-cores are necessary.
Condition of oil
*
3-1. Automatic Backup
This system includes an emergency automatic backup function that allows the air conditioner to operate during the
period after trouble occurs until repairs are made. However, during repair and at other times, use manual backup
operation.
For details, see the item “11. Backup Operation” under the section 1.
3-2. Manual Backup
3-2-1. Backup operation by disconnecting the outdoor unit
(1) Changing the outdoor unit control PCB settings
This backup operation is the conventional method of backup operation. It involves disconnecting the failed outdoor
unit from the system, and operating only the normal outdoor units.
For details, see “(2) Manual Backup Operation” of “11. Backup Operation” under the section 1.
After the alarm details are sent to the control device, control for automatic backup operation begins when the
ON/OFF button of the wired remote controller is pressed again (operation is started after the alarm is cleared).
During this operating mode, “ ” blinks on the wired remote controller only to inform the user that operation
is in backup mode. However this is not displayed on any other control devices.
Backup operation is intended as emergency operation until repairs are completed.
Have repairs made as soon as possible.
2WAY VRF SYSTEM
Outdoor Unit Repair Procedures
3. Backup Operation
If the power is not reset on the control PCB of the No. 1 outdoor unit (main unit),
backup mode operation will continue after the repairs are completed.
In order to cancel automatic backup mode, it is necessary to reset the power of all the outdoor units in the system.
Settings at No. 1 unit (main unit)
Settings at normal outdoor units other than the No. 1 unit
No particular changes
Settings at the failed outdoor unit
No particular changes
However, close all service valves (gas tubes, liquid tube, and balance tube) at the failed outdoor unit, and
disconnect the communication wiring between the outdoor units.
Action
No change
No change
Subtract the number of failed units from the current setting.
Switch on outdoor unit control PCB
System address (SW2, SW1)
No. of indoor units (SW4, SW3)
No. of outdoor units (SW6)
Outdoor unit No. (SW5)
No change
CAUTION
SM830237-07_北米向け2WAY_VRF.indb 6
18/06/18 18:48:09
