Service Manual

85
3. Table of outdoor unit failure mode recall function
The left lamp of
OPERATION IN-
DICATOR lamp
(Indoor unit)
Abnormal point
(Failure mode/protection)
LED indication
(Outdoor P.C.
board)
Condition Remedy
Indoor/outdoor
unit failure
mode recall
function
LED 1 LED 2
OFF None (Normal) Lit Lit
2-time blink Outdoor power system Lit Lit Overcurrent protection cut-out operates 3
consecutive times within 1 minute after the
compressor gets started, or converter pro-
tection cut-out or bus-bar voltage protection
cut-out operates 3 consecutive times within
3 minutes after startup.
• Check the connection of the com-
pressor connecting wire.
• Refer to 12-6.
"How to check inverter/compressor".
• Check the stop valve.
○
3-time blink Discharge temperature thermistor Lit Once A thermistor shorts or opens during com-
pressor running.
• Refer to 12-6.
"Check of outdoor
thermistors".
○
Defrost thermistor Lit Once
Ambient temperature thermistor Lit Twice
Fin temperature thermistor Lit 3 times
P.C. board temperature thermistor Lit 4 times • Replace the outdoor control P.C. board.
Outdoor heat exchanger tempera-
ture thermistor
Lit 9 times
• Refer to 12-6.
"Check of outdoor
thermistors".
4-time blink Overcurrent Once Not lit
18A (MXZ-2C20NA2)/21 A (MXZ-3C24/3C30/4C36NA,
MXZ-3C24/3C30/4C36NA2)/28 A (MXZ-5C42NA, MXZ-
2C20/3C24/3C30NAHZ, MXZ-5C42NA2, MXZ-2C20/
3C24/3C30NAHZ2) current ows into power module.
• Reconnect compressor connector.
• Refer to 12-6.
"How to check in-
verter/compressor".
• Check the stop valve.
—
5-time blink Discharge temperature Lit Lit
The discharge temperature exceeds 239°F (MXZ-
2C20NA2)/222.8°F (MXZ-3C24/3C30/4C36NA,
MXZ-3C24/3C30/4C36NA2)/240.8°F (MXZ-2C20/
3C24/3C30NAHZ, 5C42NA, MXZ-2C20/3C24/
3C30NAHZ2, 5C42NA2) during operation.
Compressor can restart if discharge temperature
thermistor reads 176°F (MXZ-2C20NA2)/203°F
(MXZ-3C24/3C30/4C36NA, MXZ-3C24/3C30/
4C36NA2)/212°F (MXZ-2C20/3C24/3C30NAHZ,
5C42NA, MXZ-2C20/3C24/3C30NAHZ2, 5C42NA2)
or less 3 minutes later.
• Check refrigerant circuit and refrig-
erant amount.
• Refer to 12-6.
"Check of LEV".
—
6-time blink High pressure Lit Lit
The outdoor heat exchanger temperature ex-
ceeds 158°F during cooling or the indoor gas
pipe temperature
exceeds 158°F during heating.
• Check refrigerant circuit and refrig-
erant amount.
• Check the stop valve.
—
7-time blink Fin temperature 3 times Not lit
The n temperature exceeds 190°F (MXZ-3C24/3C30/
4C36NA, MXZ-2C20/3C24/3C30/4C36NA2)/192°F
(MXZ-2C20/3C24/3C30NAHZ, 5C42NA, MXZ-2C20/
3C24/3C30NAHZ2, 5C42NA2) during operation.
• Check around outdoor unit.
• Check outdoor unit air passage.
• Refer to 12-6.
"Check of outdoor
fan motor".
—
P.C. board temperature 4 times Not lit
The P.C. board temperature exceeds 152°F (MXZ-
3C24/3C30/4C36NA, MXZ-2C20/3C24/3C30/
4C36NA2)/189°F (MXZ-2C20/3C24/3C30NAHZ,
MXZ-5C42NA, MXZ-2C20/3C24/3C30NAHZ2,
5C42NA2) during operation.
8-time blink Outdoor fan motor Lit Lit A failure occurs 3 consecutive times within
30 seconds after the fan gets started.
• Refer to 12-6.
"Check of outdoor
fan motor".
—
4-way valve switching operation
abnormality.
Lit
12 times Connector of R.V. coil is disconnected, poorly
connected or 4-way valve is faulty.
• Refer to 12-6. "Check of R.V. coil".
• Check the 4-way valve.
○
9-time blink Outdoor control system Lit 5 times Nonvolatile memory data cannot be read
properly.
• Replace the outdoor control P.C.
board.
○
10-time blink Low discharge temperature
protection
Lit Lit The frequency of the compressor is kept 80
Hz 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 12-6.
"Check of LEV".
—
11-time blink Communication error
between P.C. boards
Lit 6 times
Communication error occurs between the out-
door control P.C. board and outdoor power P.C.
board for more than 10 seconds.
• Check the connecting wire between
outdoor control P.C. board and out-
door power P.C. board.
—
The communication between boards protec-
tion cut-out operates 2 consecutive times.
○
Current sensor Lit 7 times A short or open circuit is detected in the cur-
rent sensor during compressor operating.
—
—
Current sensor protection cut-out operates
2 consecutive times.
○
Zero cross detecting circuit 5 times Not lit Zero cross signal cannot be detected while
the compressor is operating.
• Check the connecting wire among
outdoor control P.C. board and out-
door power P.C. board.
—
The protection cut-out of the zero cross de-
tecting circuit operates 10 consecutive times.
○
Converter 5 times Not lit A failure is detected in the operation of the
converter during operation.
• Check the voltage of power supply.
• Replace the outdoor power P.C.
board.
—
Bus-bar voltage 5 times Not lit The bus-bar voltage exceeds 400 V or falls
to low level during compressor operating.
• Check the voltage of power supply.
•
Replace the outdoor power P.C. board
or the outdoor control P.C. board.
14-time blink 4-way valve switching operation
abnormality.
Lit 12 times Connector of R.V. coil is disconnected, poorly
connected or 4-way valve is faulty.
• Refer to 12-6. "Check of R.V. coil".
• Check the 4-way valve.
○
15-time blink LEV and drain pump Lit Lit The indoor unit detects an abnormality in
the LEV and drain pump.
• Refer to 12-6. "Check of LEV".
•
Check the drain pump of the indoor unit.
—
NOTE: Blinking patterns of this mode differ from the ones of
TROUBLESHOOTING CHECK TABLE (12-4.).
OBH702H