Mitsubishi Electric PUZ-ZM60VHA2 Service Manual page 48

Check Code Abnormal points and detection method
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°C
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.
b) The liquid pipe temperature or the
PL
condenser/evaporator temperature is 75°C
or more.
These detected errors will not be
cancelled until the power source is
reset.
OCH771
Cause
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.
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)
48
Judgment and action
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 3
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 3
ON
OFF
A-Control Service Tool SW2 setting
23 Check reversed connection of extension
pipe or reversed 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 "10-5. 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.
)
4 5 6
ON
OFF
4 5 6
ON
OFF