Mitsubishi Electric Mr.Slim PUZ-HA30NHA2 Service Manual page 32

Error Code Abnormal point and detection method
Serial communication error
1. Abnormal if serial communication
between outdoor controller circuit board
and outdoor power circuit board is defec-
tive.
Ed
(0403)
2. Abnormal if communication between out-
door controller circuit board and M-NET
board is not available.
Pipe temperature
<Cooling mode>
Detected as abnormal when the pipe tem-
perature is not in the cooling range 3 min-
utes 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 : Indoor pipe temperature
(TH2 or TH5) – room temperature
(TH1) [ -3 deg [-5.4˚F]
TH: Lower temperature between liquid pipe
temperature and condenser/
evaporator temperature
P8
<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 heat-
ing 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 deg [5.4˚F] [ (Condenser/
Evaporator temperature(TH5) –
room temperature(TH1))
Case
1 Breaking of wire or contact
failure of connector CN2
between the outdoor controller
circuit board and the outdoor
power circuit board
2 Breaking of wire or contact
failure of connector CN4
between the outdoor controller
circuit board and the outdoor
power circuit board
3 Defective communication circuit
of outdoor power circuit board
4 Defective communication cir-
cuit of outdoor controller circuit
board for outdoor power circuit
board
1 Breaking of wire or contact
failure of connector between
outdoor controller circuit board
and M-NET board
2 Contact failure of M-NET board
power supply line
3 Noise has entered into M-NET
transmission wire.
1 Slight temperature difference
between indoor room tempera-
ture and pipe <liquid or con-
denser/evaporator> tempera-
ture thermistor
• Shortage of refrigerant
• Disconnected holder of pipe
<liquid or condenser/
evaporator> thermistor
• Defective refrigerant circuit
2 Converse connection of exten-
sion pipe (on plural units con-
nection)
3 Converse 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 com-
pletely.
32
Judgment and action
12 Check connection of each connector CN2
and CN4 between the outdoor controller
circuit board and the outdoor power circuit
board.
3 Replace outdoor power circuit board.
4 Replace outdoor controller circuit board.
1 Check disconnection, looseness, or breaking of
connection wire between outdoor controller cir-
cuit board (CNMNT) and M-NET board (CN5).
2 Check disconnection, looseness, or breaking
of connection wire between outdoor controller
circuit board(CNMNT) and M-NET board (CND).
3 Check M-NET transmission wiring method.
1~4 Check pipe <liquid or condenser/
evaporator> temperature with room tem-
perature 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.
(
Conduct temperature check with outdoor
controller circuit board after connecting
'A-Control Service Tool(PAC-SK52ST)'.
Temperature display of indoor condenser/
Temperature display of indoor liquid pipe
evaporator pipe Indoor 1
Indoor 1
1 2 3 4 5 6 1 2
ON
OFF
Temperature display of indoor condenser/
Temperature display of indoor liquid pipe
evaporator pipe Indoor 2
Indoor 2
1 2 3 4 5 6 1 2
ON
OFF
A-Control Service Tool SW2 setting
23 Check converse connection of extension
pipe or converse wiring of indoor/outdoor
unit connecting wire.
)
3 4 5 6
ON
OFF
3 4 5 6
ON
OFF