Mitsubishi Electric PUZ-SWM60VAA Service Manual page 32

Check code Abnormal point and detection method
Indoor/outdoor unit communication
error (Signal receiving error) (Outdoor
unit)
Abnormal if outdoor controller circuit board
could not receive anything normally for 3
E8
minutes.
(6840)
Indoor/outdoor unit communication
error (Transmitting error) (Outdoor unit)
Abnormal if "0" receiving is detected 30
times continuously though outdoor
controller circuit board has transmitted
E9
"1".
(6841)
Abnormal if outdoor controller circuit
board could not find blank of
transmission path for 3 minutes.
Non defined check code
This code is displayed when non defined
check code is received.
EF
(6607
or
6608)
Serial communication error
Abnormal if serial communication
between outdoor controller circuit board
and outdoor power circuit board is
defective.
Ed
(0403)
Pipe 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 defrost-
ing mode is over)
P8
Heating range : 3°C ≤ (Condenser/
Evaporator temperature(TH5)−
room temperature(TH1))
OCH809A
Cause
Contact failure of indoor/
outdoor unit connecting wire
Defective communication circuit
of outdoor controller circuit board
Defective communication circuit
of indoor controller board
Noise has entered into indoor/
outdoor unit connecting wire.
Indoor/ outdoor unit connecting
wire has contact failure.
Defective communication circuit
of outdoor controller circuit board
Noise has entered power supply.
Noise has entered indoor/
outdoor unit connecting wire.
Noise has entered transmission
wire of remote controller.
Noise has entered indoor/
outdoor unit connecting wire.
Outdoor unit is not inverter
models.
Breaking of wire or contact
failure of connector CN2
between the outdoor controller
circuit board and the outdoor
power circuit board
Breaking of wire or contact
failure of connector CN4
between the outdoor controller
circuit board and the outdoor
power circuit board
Defective communication circuit
of outdoor power circuit board
Defective communication circuit
of outdoor controller circuit
board for outdoor power circuit
board
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
Converse connection of
extension pipe (on plural units
connection)
Converse wiring of indoor/
outdoor unit connecting wire
(on plural units connection)
Defective detection of indoor
room temperature and pipe
<condenser/evaporator>
temperature thermistor
Stop valve is not opened
completely.
32
Judgment and action
Check disconnection or looseness of indoor/
outdoor unit connecting wire of indoor or
outdoor units.
– Turn the power off, and on again to check.
Replace indoor controller board or outdoor
controller circuit board if abnormality is
displayed again.
Check disconnection or looseness of indoor/
outdoor unit connecting wire.
– Turn the power off, and on again to check.
Replace outdoor controller circuit board if
abnormality is displayed again.
Turn the power off, and on again to check.
Replace indoor controller board or outdoor
controller circuit board if abnormality is
displayed again.
Replace outdoor unit with inverter type
outdoor unit.
Check connection of each connector CN2
and CN4 between the outdoor controller cir-
cuit board and the outdoor power circuit
board.
Replace outdoor power circuit board.
Replace outdoor controller circuit board.
– 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.
(
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
Check converse connection of extension
pipe or converse wiring of indoor/outdoor
unit connecting wire.
Check the stop valve is opened completely.
)
3 4 5 6
ON
OFF
3 4 5 6
ON
OFF