Mitsubishi Electric MXZ-2C30VA, Service Manual

Page: 90 / 396

90
MXZ-6C
Upper or
left lamp of
OPERATION
INDICATOR
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) Lighted Lighted
2-time fl ash Outdoor power system Lighted Lighted Overcurrent protection cut-out operates
3 consecutive times, bus-bar voltage
protection cut-out operates 3 consecu-
tive times, or primary current protection
cut-out operates 3 consecutive times
within 1minute after the compressor
gets started. • Check the connection of
the compressor connecting
wire.
• Refer to 11-6. How to
check inverter/compressor.
• Check the stop valve.
○
3-time fl ash Discharge temperature thermis-
tor Lighted Once 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 • Replace the power board
(MXZ-6C120VA)
/outdoor pow-
er P.C. board
(MXZ-6C122VA)
.
P.C. board temperature thermis-
tor Lighted 4 times • Replace the power board
(MXZ-6C120VA)
/outdoor pow-
er P.C. board
(MXZ-6C122VA)
.
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
40 A current fl ows into intelligent power
module.
• Reconnect compressor con-
nector.
• Refer to 11-6. "How to
check inverter/compressor".
• Check the stop valve.
—
Out-of-step protection 9 times Not
lighted
Waveform of compressor current is dis-
torted. • Refer to 11-6. " How to
check inverter/compressor.
5-time fl ash Discharge temperature Lighted Lighted Discharge temperature exceeds 114 °C
during operation.
Compressor can restart if discharge
temperature thermistor reads 100 °C or
less 3 minutes later. • Check the refrigerant circuit
and the refrigerant amount.
• Refer to 11-6. "Check of
LEV".
—
6-time fl ash High pressure Lighted Lighted High-pressure is detected with the
high-pressure switch (HPS) during op-
eration. • Check the refrigerant circuit
and the refrigerant amount.
• Check the stop valve.
—
The outdoor heat exchanger tempera-
ture exceeds 70 °C during cooling or
the indoor gas pipe temperature ex-
ceeds 70°C during heating.
7-time fl ash Fin temperature 3 times Not
lighted
The fin temperature exceeds
:
110 °C
(MXZ-6C120VC- E1 )
/ 105°C
(MXZ-
6C120VC- E2 , MXZ-6C122VC- E1
) dur-
ing operation.
• Check around the outdoor
unit.
• Check the 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
95 °C during operation.
8-time fl ash Outdoor fan motor Lighted Lighted The fan motor speed is 50 rpm or less
or 1500 rpm or more for 1 minute, or
the fan motor speed is 100 rpm or
less for 15 seconds when the outside
temperature is 20 °C or more.
• 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 properly. • Replace the control P.C. board
( M X Z - 6 C 1 2 0 VA )
/ o u t d o o r
control P.C. board
( M X Z -
6C122VA)
.
• Replace the power board
(MXZ-6C120VA)
/outdoor pow-
er P.C. board
(MXZ-6C122VA)
.
○
10-time fl ash Discharge temperature Lighted Lighted The frequency of the compressor is
kept 58Hz or more and the discharge
temperature is kept under 50 °C (cool-
ing)/40 °C (heating) for more than 40
minutes. • Check the refrigerant circuit
and the refrigerant amount.
• Refer to 11-6. "Check of
LEV".
—
OBH584G