Table Of Outdoor Unit Failure Mode Recall Function - Mitsubishi Electric MXZ-2C20NA2-U1 Service Manual

The left lamp of
OPERATION IN- Abnormal point
DICATOR lamp (Failure mode/protection)
(Indoor unit)
OFF None (Normal)
2-time blink Outdoor power system
3-time blink Discharge temperature thermistor
Defrost thermistor
Ambient temperature thermistor
Fin temperature thermistor
P.C. board temperature thermistor
Outdoor heat exchanger tem-
perature thermistor
4-time blink Overcurrent
5-time blink Discharge temperature
6-time blink High pressure
7-time blink Fin temperature
P.C. board temperature
8-time blink Outdoor fan motor
9-time blink Outdoor control system
10-time blink Low discharge temperature
protection
11-time blink Communication error
between P.C. boards
Current sensor
Zero cross detecting circuit
Converter
Bus-bar voltage
15-time blink LEV and drain pump
OBH702G
NOTE: Blinking patterns of this mode differ from the ones of
LED indication
(Outdoor P.C.
Condition
board)
LED 1 LED 2
Lit Lit
Lit Lit Overcurrent protection cut-out operates
3 consecutive times within 1 minute after
the compressor gets started, or converter
protection cut-out or bus-bar voltage
protection cut-out operates 3 consecutive
times within 3 minutes after startup.
Lit Once A thermistor shorts or opens during
compressor running.
Lit Once
Lit Twice
Lit 3 times
Lit 4 times
Lit 9 times
Once Not lit 18A (MXZ-2C20NA2)/21 A (
Lit Lit The discharge temperature exceeds 239°F (MXZ-
2C20NA2)/222.8°F (
Compressor can restart if discharge temperature
thermistor reads 176°F (MXZ-2C20NA2) 203°F
(
)/212°F (
or less 3 minutes later.
Lit Lit The outdoor heat exchanger temperature ex-
ceeds 158°F during cooling or the indoor gas
pipe temperature exceeds 158°F during heating.
3 times Not lit
(
4 times Not lit The P.C. board temperature exceeds 152°F (MXZ-
4C36NA2)/189°F (
5C42NA2) during operation.
Lit Lit A failure occurs 3 consecutive times within
30 seconds after the fan gets started.
Lit 5 times Nonvolatile memory data cannot be read
properly.
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.
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.
The communication between boards protec-
tion cut-out operates 2 consecutive times.
Lit 7 times A short or open circuit is detected in the cur-
rent sensor during compressor operating.
Current sensor protection cut-out oper-
ates 2 consecutive times.
5 times Not lit Zero cross signal cannot be detected
while the compressor is operating.
The protection cut-out of the zero cross de-
tecting circuit operates 10 consecutive times.
5 times Not lit A failure is detected in the operation of the
converter during operation.
5 times Not lit The bus-bar voltage exceeds 400 V or
falls to low level during compressor oper-
ating.
Lit Lit The indoor unit detects an abnormality in
the LEV and drain pump.
81
TROUBLESHOOTING CHECK TABLE (11-4.).
• Check the connection of the com-
pressor connecting wire.
• Refer to 11-6.
"How to check inverter/compres-
sor".
• Check the stop valve.
• Refer to 11-6.
thermistors".
• Replace the outdoor control P.C. board.
• Refer to 11-6.
thermistors".
• Reconnect compressor connector.
)/28 A ( • Refer to 11-6.
verter/compressor".
• Check the stop valve.
• Check refrigerant circuit and refrig-
erant amount.
)/240.8°F (MXZ-2C20 • Refer to 11-6.
) during operation.
)
• Check refrigerant circuit and refrig-
erant amount.
• Check the stop valve.
)/192°F
• Check around outdoor unit.
) during operation.
• Check outdoor unit air passage.
• Refer to 11-6.
fan motor".
• Refer to 11-6.
fan motor".
• Replace the outdoor control P.C.
board.
• Check refrigerant circuit and refrig-
erant amount.
• Refer to 11-6.
• Check the connecting wire between
outdoor control P.C. board and out-
door power P.C. board.
• Check the connecting wire among
outdoor control P.C. board and out-
door power P.C. board.
• Check the voltage of power supply.
• Replace the outdoor power P.C.
board.
• Check the voltage of power supply.
• Replace the outdoor power P.C. board
or the outdoor control P.C. board.
• Refer to 11-6.
• Check the drain pump of the indoor unit.
Indoor/
outdoor unit
Remedy
failure mode
recall function
"Check of outdoor
"Check of outdoor
"How to check in-
—
"Check of LEV".
—
—
—
"Check of outdoor
"Check of outdoor
—
—
"Check of LEV".
—
—
—
—
—
"Check of LEV".
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