Mitsubishi Electric MUZ-AP25VG, Service Manual

Page: 45 / 76

45
3. Table of outdoor unit failure mode recall function
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (12-3.).
Upper lamp
(Indoor unit)
Abnormal point
(Failure mode/protection)
LED indication
(Outdoor P.C. board)
Condition Remedy
Indoor/outdoor
unit failure
mode recall
function
Outdoor unit
failure mode
recall function
OFF None (Normal) — — — — —
1-time blink
2.5 seconds
OFF Indoor/outdoor
communication, receiving
error
—
Any signals from the inverter P.C.
board cannot be received normally for
3 minutes. •Refer to 12-5. How
to check miswiring and
serial signal error.
○ ○
Indoor/outdoor
communication, receiving
error
—
Although the inverter P.C. board
sends signal "0", signal "1" has been
received 30 consecutive times. •Refer to 12-5. How
to check miswiring and
serial signal error.
2-time blink
2.5 seconds
OFF Outdoor power system
—
Overcurrent protection cut-out
operates 3 consecutive times within
1 minute after the compressor gets
started.
• Reconnect
connectors.
• Refer to 12-5. "How
to check inverter/
compressor".
• Check stop valve.
○ ○
3-time blink
2.5 seconds
OFF Discharge temperature
thermistor 1-time blink every
2.5 seconds Thermistor shorts or opens during
compressor running.
• Refer to 12-5.
"Check of outdoor
thermistors".
Defective outdoor
thermistors can be
identified by checking
the blinking pattern of
LED.
○ ○
Defrost thermistor
Fin temperature thermistor 3-time blink
2.5 seconds OFF
P.C. board temperature
thermistor 4-time blink
2.5 seconds OFF
Ambient temperature
thermistor 2-time blink
2.5 seconds OFF
Outdoor heat exchanger
temperature thermistor
—
4-time blink
2.5 seconds
OFF Overcurrent 11-time blink
2.5 seconds OFF
Large current flows into power module
(IC700).
• Reconnect
compressor connector.
• Refer to 12-5. "How
to check inverter/
compressor".
• Check stop valve.
—
○
Compressor synchronous
abnormality (Compressor
start-up failure protection) 12-time blink
2.5 seconds OFF Waveform of compressor current is
distorted.
• Reconnect
compressor connector.
• Refer to 12-5. "How
to check inverter/
compressor".
—
○
5-time blink
2.5 seconds
OFF Discharge temperature
—
Temperature of discharge temperature
thermistor exceeds 116°C, compressor
stops.
Compressor can restart if discharge
temperature thermistor reads 100°C or
less 3 minutes later.
• Check refrigerant
circuit and refrigerant
amount.
• Refer to 12-5. "Check
of LEV".
—
○
6-time blink
2.5 seconds
OFF High pressure
—
Temperature of indoor coil thermistor
exceeds 70°C in HEAT mode.
Temperature of defrost thermistor
exceeds 70°C in COOL mode.
• Check refrigerant
circuit and refrigerant
amount.
• Check stop valve.
—
○
7-time blink
2.5 seconds
OFF Fin temperature/P.C. board
temperature 7-time blink
2.5 seconds OFF
Temperature of fin temperature thermistor
on the inverter P.C. board exceeds 75 ~
86°C (
MUZ-AP25/35/42/50/60 ) / 75 ~ 80°C
( MUZ-AP71 ), or temperature of P.C. board
temperature thermistor on the inverter
P.C. board exceeds 72 ~ 85°C (
MUZ-
AP25/35/42/50/60 ) / 70 ~ 75°C ( MUZ-
AP71 ).
• Check around outdoor
unit.
• Check outdoor unit air
passage.
• Refer to 12-5. "Check
of outdoor fan motor".
—
○
8-time blink
2.5 seconds
OFF Outdoor fan motor
—
Outdoor fan has stopped 3 times in a
row within 30 seconds after outdoor
fan startup.
• Refer to 12-5. "Check
of outdoor fan motor".
Refer to 12-5. "Check
of inverter P.C. board".
—
○
9-time blink
2.5 seconds
OFF Nonvolatile memory data 5-time blink
2.5 seconds OFF Nonvolatile memory data cannot be
read properly.
• Replace the inverter
P.C. board.
○
○
Power module (IC700) 6-time blink
2.5 seconds OFF The interface short circuit occurs in the
output of the power module (IC700).
The compressor winding shorts circuit.
• Refer to 12-5. "How
to check inverter/
compressor".
—
OBH789A