Panasonic U-20ME1E81, Service Manual

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2WAY SYSTEM
Control Functions-Outdoor Unit
1
12. Backup Operation
12-1-2. Start of automatic backup operation
If the above alarms occur, the alarm is displayed on the remote controller, etc. Pressing the remote contoller
button again starts automatic backup mode.
12-1-3. Backup operation information display
If a wired remote controller is present,
12-1-4. Check for Blinks When Automatic Backup Setting
When operating the automatic backup by setting the outdoor unit EEPROM, blink check on the remote controller
and centralized control systems is enabled to change for non-displayed.
display blinks during operation.
12-2. Manual Backup Operation
The manual backup can be used when it is necessary to close the service valve for maintenance etc.
- Backup operation procedure
[1] Disconnecting the failed outdoor unit
(1) Reduce the number of outdoor units set at outdoor unit No.1 by only the number of failed outdoor units.
(2) At the SW7 switch on the PCB of the failed outdoor unit, turn ON the switches for all compressor to dis-
able, and turn ON the “backup” switch.
Outdoor unit hp 8 hp, 10 hp 12 hp, 14 hp, 16 hp 18 hp, 20 hp
Switches to turn ON INV+BU INV+AC1+BU INV+AC1+AC2+BU
(3) Close all service valves at the failed outdoor units.
(4) Reset the power at outdoor unit No.1.
* The outdoor unit that backed up all compressors is not controlled by CCU (main outdoor unit). Even if all
compressors of the main outdoor unit are backed up, they are not controlled by CCU. However, the CCU
function stays active.
[2] Disabling operation of 1 compressor
At the SW7 switch on the PCB of the failed outdoor unit, turn ON the switch for the compressor to disable,
and turn ON the “backup” switch.
<SW7 switch>
INV AC1 AC2
Backup
ON
OFF
(A) Compressor 2 backup (B) Compressor 3 backup
ON
OFF
ON
OFF
• In order to per form simultaneous backup operation for 2 or more compressors, use a combination of the switch
settings shown above.
EEPROM setting in main outdoor unit
CODE: 49
Setting No.
0
1
Display (factory preset mode)
Non-displayed
12. Backup Operation
2WAY SYSTEM
Control Functions-Outdoor Unit
* Backup operation caused by an alarm listed in “alarm list 2” will finish automatically after 24 hours if the same
alarm does not occur again for 24 hours.
A : When there is one outdoor unit in the system, only compressor that has sensor failure stops.
B : When there is one outdoor unit in the system, the backup operation does not work.
Alarm list 2 (Backup operation continues as long as the problem is not solved.)
Discharge temperature sensor failure for compressor 1
Discharge temperature sensor failure for compressor 2
Gas temperature sensor in heat exchanger 1
Liquid temperature sensor in heat exchanger 1
Ambient air temperature
Suction temperature
Temp. sensor at refrigerant gas outlet of dual-tube
High pressure sensor failure
Low pressure sensor failure
Gas temperature sensor in heat exchanger 2
Liquid temperature sensor in heat exchanger 2
Compressor 1 discharge temperature sensor disconnected
Oil temperature sensor 1 (Inverter compressor)
Compressor 2 CT sensor disconnected or short-circuit
Compressor 3 CT sensor disconnected or short-circuit
Compressor 2 discharge temperature sensor disconnected
Compressor 3 discharge temperature sensor disconnected
Oil temperature sensor 2 (Constant-speed compressor 1)
Oil temperature sensor 3 (Constant-speed compressor 2)
Compressor 1 discharge temperature trouble
Compressor 2 discharge temperature trouble
Compressor 3 discharge temperature trouble
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
Alarm display
F05
F04
F06
F08
F07
F12
F16
F14
F23
F17
F24
H08
H05
H13
H27
H28
H15
H23
H25
P17
P18
P03
When there are multiple outdoor units in the system, only the outdoor unit which contains the problem
stops but the other outdoor units in the system operate normally.
When there are multiple outdoor units in the system, only the outdoor unit which contains the problem
stops but the other outdoor units in the system operate normally.
SM830204-05_2WAY SYS.indb 39 2015/01/21 17:00:05