Panasonic U-120ME2U9 Service Manual page 45

12. Backup Operation
11. Backup Operation
Alarm list 2 (Backup operation continues as long as the problems are not solved.)
Alarm display
DISCH1 thermistor at the discharge of 1st compressor reading is abnormal
F04
F05 DISCH2 thermistor at the discharge of 2nd compressor reading is abnormal
EXG1 thermistor at the gas side of 1st heat exchanger of the outdoor unit
F06
has failure (EXG1)
EXL1 thermistor at the liquid side of 1st heat exchanger of the outdoor unit
F07
has failure (EXL1)
F08 TO thermistor for outdoor ambient air temperature has failure (TO)
F12 SCT thermistor at the suction refrigerant of compressors has failure (SCT)
SCG thermistor at the outlet of subcooling heat exchanger in outdoor unit
F14
has failure (SCG)
F16 High pressure sensor of the outdoor unit has failure (HPS)
F17 Low pressure sensor of the outdoor unit has failure (LPS)
EXG2 thermistor at the gas side of 2nd heat exchanger of the outdoor unit
F23
has failure (EXG2)
EXL2 thermistor at the liquid side of 2nd heat exchanger of the outdoor unit
F24
has failure (EXL2)
DISCH1 thermistor at the discharge of 1st compressor is disconnected,
H05
shorted or misplaced (DISCH1)
H08 OIL1 thermistor for the oil of 1st compressor has failure (OIL1)
DISCH2 thermistor at the discharge of 2nd compressor is disconnected,
H15
shorted or misplaced (DISCH2)
H27 OIL2 thermistor for the oil of 2nd compressor has failure (OIL2)
P03 1st compressor discharge temperature too high
P17 2nd compressor discharge temperature too high
A : When there is one outdoor unit in the system, only compressor that has sensor failure stops.
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.
B : When there is one outdoor unit in the system, the backup operation does not work.
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.
* 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.
1-2. Start of automatic backup operation
If the above alarms occur, the alarm is displayed on the remote controller, etc.
Pressing the remote controller button again starts automatic backup mode.
1-3. Backup operation information display
If a wired remote controller is present, display blinks during operation.
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3WAY SYSTEM
2WAY VRF SYSTEM
Control Functions
Control Functions
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