19
OCH724
Check Code
Abnormal point and detection method
Cause
Countermeasure
P8
1
Slight temperature difference
between indoor room
temperature and pipe <liquid
or condenser/evaporator>
temperature thermistor
• Shortage of refrigerant
• Disconnected holder of pipe
<liquid or condenser /
evaporator> thermistor
• Defective refrigerant circuit
2
Reversed connection of
extension pipe (on plural units
connection)
3
Reversed wiring of indoor/
outdoor unit connecting wire
(on plural units connection)
4
Defective detection of indoor
room temperature and pipe
<condenser/evaporator>
temperature thermistor
5
Stop valve is not opened
completely.
Pipe temperature
<Cooling mode>
Detected as abnormal when the pipe
temperature is not in the cooling range
3 minutes after compressor start and 6
minutes after the liquid or condenser/
evaporator pipe is out of cooling range.
Note 1: It takes at least 9 minutes to
detect.
Note 2: Abnormality P8 is not detected in
drying mode.
Cooling range : −
3°C
]
(TH
−
TH1)
TH: Lower temperature between:
liquid pipe temperature (TH2) and
condenser/evaporator temperature
(TH5)
TH1: Intake temperature
<Heating mode>
When 10 seconds have passed after the
compressor starts operation and the hot
adjustment mode has finished, the unit is
detected as abnormal when condenser/
evaporator pipe temperature is not in
heating range within 20 minutes.
Note 3: It takes at least 27 minutes to
detect abnormality.
Note 4: It excludes the period of defrosting.
(Detection restarts when defrosting
mode is over.)
Heating range: 3°C
[
(TH5
−
TH1)
14
Check pipe <liquid or condenser/
evaporator> temperature with room
temperature display on remote controller
and outdoor controller circuit board.
Pipe <liquid or condenser/evaporator>
temperature display is indicated by
setting SW2 of outdoor controller circuit
board as follows.
23
Check reversed connection of extension
pipe or reversed wiring of indoor/outdoor
unit connecting wire.
P9
Pipe temperature thermistor /
Condenser-Evaporator (TH5)
1
The unit is in 3-minute resume protection
mode if short/open of thermistor is
detected. Abnormal if the unit does not
get back to normal within 3 minutes. (The
unit returns to normal operation, if it has
been reset normally.)
2
Constantly detected during cooling,
drying, and heating operation (except
defrosting)
Short: 90°C or more
Open:
−
40°C or less
1
Defective thermistor
characteristics
2
Contact failure of connector
(CN44) on the indoor controller
board (Insert failure)
3
Breaking of wire or contact
failure of thermistor wiring
4
Defective refrigerant
circuit iscausing thermistor
temperature of 90°C or more or
−40°C or less.
5
Defective indoor controller
board
1
–
3
Check resistance value of thermistor.
For characteristics, refer to (P1).
2
Check contact failure of connector (CN44) on
the indoor controller board.
Refer to "9-6. TEST POINT DIAGRAM".
Turn the power on and check restart after
inserting connector again.
4
Operate in test run mode and check pipe
<condenser/evaporator> temperature with
outdoor controller circuit board. If pipe
<condenser/evaporator> temperature is
extremely low (in cooling mode) or high (in
heating mode), refrigerant circuit may have
defect.
5
Operate in test run mode and check pipe
<condenser/evaporator> temperature
with outdoor control circuit board. If there
is extreme difference with actual pipe
<condenser/evaporator> temperature, replace
indoor controller board.
No abnormality when above countermesures
have no problems.
Turn the power off and on again to operate.
In the case of checking pipe temperature
with outdoor controller circuit board, be
sure to connect A-control service tool (PAC-
SK52ST).
*1
*1: only P-series outdoor unit
In the case of checking pipe temperature
with outdoor controller circuit board, be
sure to connect A-control service tool (PAC-
SK52ST).
*1
