58
3. Outdoor unit failure mode table
MXZ-2B/3B/4B
NOTE
: Blinking patterns of this mode differ from the ones of Troubleshooting check table (11-4.).
The left lamp of
OPERATION IN-
DICATOR lamp
(Indoor unit)
Abnormal point
(Failure mode/protection)
LED indication
(Outdoor P.C.
board)
Condition
Remedy
Indoor/out-
door unit
failure mode
recall function
LED 1
LED 2
OFF
None (Normal)
Lighted Lighted
2-time
fl
ash
Outdoor power system
Lighted Lighted Overcurrent protection cut-out operates 3 con-
secutive times within 1 minute after the com-
pressor gets started, or converter protection
cut-out or bus-bar voltage protection cut-out
operates 3 consecutive times within 3 minutes
after start-up.
• Check the connection
of the compressor
connecting wire.
• Refer to 11-6.
"How to check inverter/compres-
sor".
• Check the stop valve.
○
3-time
fl
ash
Discharge temperature thermistor
Lighted
Once
A thermistor shorts or opens during
compressor running.
• Refer to 11-6. "Check of outdoor
thermistors".
○
Defrost thermistor
Lighted
Once
Ambient temperature thermistor
Lighted
Twice
Fin temperature thermistor
Lighted 3 times
P.C. board temperature thermis-
tor
Lighted 4 times
• Replace the outdoor electronic con-
trol P.C. board.
Outdoor heat exchanger tem-
perature thermistor
Lighted 9 times
• Refer to 11-6. "Check of outdoor
thermistors".
4-time
fl
ash
Overcurrent
Once
Not
lighted
28 A current
fl
ows into intelligent power mod-
ule.
• Reconnect compressor connector.
• Refer to 11-6. "How to check in-
verter/compressor".
• Check the stop valve.
—
5-time
fl
ash
Discharge temperature
Lighted Lighted The discharge temperature exceeds 240.8°F
during operation.
Compressor can restart if discharge tempera-
ture thermistor reads 212°F or less 3 minutes
later.
• Check refrigerant circuit and refrig-
erant amount.
• Refer to 11-6. "Check of LEV".
—
6-time
fl
ash
High pressure
Lighted Lighted The outdoor heat exchanger temperature ex-
ceeds 158°F during cooling or the indoor gas
pipe temperature exceeds 158°F during heat-
ing.
• Check refrigerant circuit and refrig-
erant amount.
• Check the stop valve.
—
7-time
fl
ash
Fin temperature
3 times
Not
lighted
The fin temperature exceeds 188.6°F during
operation.
• Check around outdoor unit.
• Check outdoor unit air passage.
• Refer to 11-6. "Check of outdoor
fan motor".
—
P.C. board temperature
4 times
Not
lighted
The P.C. board temperature exceeds 158°F
during operation.
8-time
fl
ash
Outdoor fan motor
Lighted Lighted A failure occurs 3 consecutive times within 30
seconds after the fan gets started.
• Refer to 11-6. "Check of outdoor
fan motor".
—
9-time
fl
ash
Nonvolatile memory data
Lighted 5 times Nonvolatile memory data cannot be read prop-
erly.
• Replace the outdoor electronic control
P.C. board.
○
10-time
fl
ash
Discharge temperature
Lighted Lighted The frequency of the compressor is kept 80Hz
or more and the discharge temperature is kept
under 102.2°F for more than 20 minutes.
• Check refrigerant circuit and refrig-
erant amount.
• Refer to 11-6. "Check of LEV".
—
11-time
fl
ash
Communication error
between P.C. boards
Lighted 6 times Communication error occurs between the
electronic control P.C. board and power board
for more than 10 seconds.
• Check the connecting wire between
outdoor electronic control P.C.
board and power board.
—
The communication between boards protection
cut-out operates 2 consecutive times.
○
Current sensor
Lighted 7 times A short or open circuit is detected in the
current sensor during compressor operating.
—
Current sensor protection cut-out operates 2
consecutive times.
○
Zero cross detecting circuit
5 times
Not
lighted
Zero cross signal cannot be detected while the
compressor is operating.
• Check the connecting wire among
electronic control P.C. board, noise
fi
lter P.C. board and power board.
—
The protection cut-out of the zero cross
detecting circuit operates 10 consecutive
times.
○
Converter
5 times
Not
lighted
A failure is detected in the operation of the
converter during operation.
• Check the voltage of power supply.
• Replace the power board.
—
Bus-bar voltage
(1)
5 times
Not
lighted
The bus-bar voltage exceeds 400V or falls to
200V or below during compressor operating.
Bus-bar voltage
(2)
Even if this protection stop is per-
formed continuously three times, it
does not mean the abnormality in
outdoor power system.
6 times
Not
lighted
The bus-bar voltage exceeds 400V or falls to
50V or below during compressor operating.
• Check the voltage of power
supply.
• Replace the outdoor
electronic control P.C. board.
15-time
fl
ash
LEV and drain pump
Lighted Lighted The indoor unit detects an abnormality
in the LEV and drain pump.
• Refer to 11-6. "Check of LEV".•
Check the drain pump of the indoor
unit.
—
OBH560G
