Mitsubishi Electric PKA-RP1.6GAL Service Technical Manual page 107

Error Code Meaning of error code and detection method
Freezing/overheating protection is
working
1 Freezing protection (Cooling mode)
The unit is in six-minute resume prevention
mode if pipe <liquid or condenser/evap-
orator> temperature stays under
-15: for three minutes, three minutes
after the compressor started. Abnormal
if it stays under -15: for three minutes
again within 16 minutes after six-minute
resume prevention mode.
2 Frost abnormality (Only for the combination
with inverter-type outdoor unit)
Suspensive abnormal if unit operates in
frost prevention mode (below) for 9
minutes or more. After that, when frost
prevention mode is released and
compressor restarts its operation, unit is
not detected as abnormal if compressor
keeps operating for 20 minutes
continuously and abnormal if compressor
stops operating within 20 minutes and
unit operates in frost prevention mode
for more than 9 minutes again. (Not
P6
abnormal if unit stops operating in frost
prevention mode within 9 minutes)
<Frost prevention mode>
If pipe <liquid or condenser-evaporator>
temperature is 2: or below when 16
minutes has passed after compressor
starts operating, unit will start operating
in frost prevention mode which stops
compressor operation. After that, when
pipe <liquid or condenser/evaporator>
temperature stays 10: or more for 3
minutes, frost prevention mode will be
released and compressor will restart its
operation.
3 Overheating protection (Heating mode)
The units is in six-minute resume
prevention mode if pipe <condenser /
evaporator> temperature is detected as
over 74: after the compressor started.
Abnormal if the temperature of over
74: is detected again within 10 minutes
after six-minute resume prevention
mode.
Abnormality of pipe temperature
<Cooling mode>
Detected as abnormal when the pipe tem-
perature is not in the cooling range 3 min-
utes later of compressor start and 6 min-
utes later of the liquid or condenser/evapo-
rator 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))
Case
(Cooling or drying mode)
1 Clogged filter (reduced airflow)
2 Short cycle of air path
3 Low-load (low temperature)
operation beyond the tolerance
range
4 Defective indoor fan motor
• Fan motor is defective.
• Indoor controller board is
defective.
5 Overcharge of refrigerant
6 Defective refrigerant circuit
(clogs)
(Heating mode)
1 Clogged filter (reduced airflow)
2 Short cycle of air path
3 Over-load (high temperature)
operation beyond the tolerance
range
4 Defective indoor fan motor
• Fan motor is defective.
• Indoor controller board is
defective.
5 Overcharge of refrigerant
6 Defective refrigerant circuit
(clogs)
7 Bypass circuit of outdoor unit
is defective.
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.
107
Judgment and action
(Cooling or drying mode)
1 Check clogs of the filter.
2 Remove shields.
4 Measure the resistance of fan motor's winding.
Measure the output voltage of fan's connector
(FAN) on the indoor controller board.
WThe indoor controller board should be
normal when voltage of AC220V to 240V is
detected while fan motor is connected.
Refer to page 119 and 120.
56 Check operating condition of refrigerant
circuit.
(Heating mode)
1 Check clogs of the filter.
2 Remove shields.
4 Measure the resistance of fan motor's
winding.
Measure the output voltage of fan's connector
(FAN) on the indoor controller board.
WThe indoor controller board should be
normal when voltage of AC220V to 240V
is detected while fan motor is connected.
Refer to page 119 and 120.
5~7Check operating condition of refrigerant
circuit.
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 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
23Check 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