Mitsubishi Electric Mr.SLIM PUZ-ZM200YKA Service Manual page 43

Check Code Abnormal points and detection method
Serial communication error
1 Abnormal if serial communication between
outdoor controller circuit board and out-
door power circuit board is defective.
Ed
(0403)
2 Abnormal if communication between
outdoor controller circuit board and
M-NET board is not available.
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 :
Indoor pipe temperature (TH2 or
TH5)−intake temperature (TH1) [ −3:
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 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: [ (Condenser/ Evaporator
temperature(TH5)−intake
temperature(TH1))
Abnormal refrigerant circuit
During Cooling, Dry, or Auto Cooling
operation, the following conditions are
regarded as failures when detected for 1
second.
a) The compressor continues to run for 30 or
more seconds.
PL
b) The liquid pipe temperature or the
condenser/evaporator temperature is 75°C
or more.
These detected errors will not be
cancelled until the power source is
reset.
OCH738
Cause
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 circuit of
outdoor controller circuit board for
outdoor power circuit board
1 Breaking of wire or contact fail-
ure of connector between out-
door 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 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 Converse connection of extension
pipe (on plural units connection)
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
completely.
1 Abnormal operation of 4-way valve
2 Disconnection of or leakage in
refrigerant pipes
3 Air into refrigerant piping
4 Abnormal operation (no rotation) of
indoor fan
· Defective fan motor
· Defective indoor control board
5 Defective refrigerant circuit
(clogging)
43
Judgment and action
12 Check connection of each connector CN2
and CN4 between the outdoor controller
circuit board and the outdoor power cir-
cuit board.
3 Replace outdoor power circuit board.
4 Replace outdoor controller circuit board.
1 Check disconnection, looseness, or breaking
of connection wire between outdoor control-
ler circuit board (CNMNT) and M-NET board
(CN5).
2 Check disconnection, looseness, or breaking
of connection wire between outdoor control-
ler 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
temperature display on remote controller
and outdoor controller circuit board.
Pipe <liquid or condenser/evaporator>
temperature display is indicated by set-
ting 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
5 Check converse connection of extension
pipe or converse wiring of indoor/outdoor
unit connecting wire.
1 When this error occurs, be sure to
replace the 4-way valve.
2 Check refrigerant pipes for disconnection
or leakage.
3 After the recovery of refrigerant, vacuum
dry the whole refrigerant circuit.
4 Refer to "10-6. HOW TO CHECK THE
PARTS".
5 Check refrigerant circuit for operation.
To avoid entry of moisture or air into
refrigerant circuit which could cause
abnormal high pressure, purge air in
refrigerant circuit or replace refrigerant.
)
3 4 5 6
ON
OFF
3 4 5 6
ON
OFF