Mitsubishi Electric PUHZ-P100VHA2 Service Manual page 57

Abnormal points and detection method
Error Code
Indoor/outdoor unit communication
error (Signal receiving error)
(Outdoor unit)
(1) Abnormal if outdoor controller circuit
E8
board could not receive anything
(6840)
normally for 3 minutes.
Indoor/outdoor unit communication
error (Transmitting error) (Outdoor unit)
(1) Abnormal if "0" receiving is detected
30 times continuously though outdoor
E9
controller circuit board has transmitted "1".
(6841)
(2) Abnormal if outdoor controller circuit
board could not find blank of transmission
path for three minutes.
Serial communication error
1. Abnormal if serial communication
between outdoor controller circuit board
and outdoor 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 later of compressor start and 6
minutes later of the liquid or condenser/
evaporator pipe is out of cooling range.
Note 1) It takes at least 9 min. to detect.
Note 2) Abnormality P8 is not detected in
drying mode.
Cooling range : Indoor pipe temperature
(TH2 or TH5) – intake temperature
(TH1) [ -3 deg
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 deg [ (Condenser/
Evaporator temperature(TH5) –
intake temperature(TH1))
OCH415G
Case
1 Contact failure of indoor/
outdoor unit connecting wire
2 Defective communication circuit
of outdoor controller circuit board
3 Defective communication circuit
of indoor controller board
4 Noise has entered into indoor/
outdoor unit connecting wire.
1 Indoor/ outdoor unit connecting
wire has contact failure.
2 Defective communication circuit
of outdoor controller circuit board
3 Noise has entered power supply.
4 Noise has entered indoor/
outdoor unit connecting wire.
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
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
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.
57
Judgment and action
1 Check disconnection or looseness of indoor/
outdoor unit connecting wire of indoor or
outdoor units.
2~4 Turn the power off, and on again to
check. Replace indoor controller board
or outdoor controller circuit board if
abnormality is displayed again.
1 Check disconnection or looseness of indoor/
outdoor unit connecting wire.
2~4 Turn the power off, and on again to
check. Replace outdoor controller circuit
board if abnormality is displayed again.
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
circuit 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
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
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
ON
OFF
A-Control Service Tool SW2 setting
23 Check converse connection of extension
pipe or converse wiring of indoor/outdoor
unit connecting wire.
)
2 3 4 5 6
ON
OFF
2 3 4 5 6
ON
OFF