Mitsubishi MUZ-HC25VA, Service Manual

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3. Outdoor unit failure mode table
The upper
lamp of
OPERATION
INDICTOR
lamp (Indoor
unit)
Abnormal point
(Failure mode / protection)
LED indication
(Outdoor P.C. board)
Condition Correspondence
Indoor/outdoor
unit failure
mode recall
function
Outdoor unit
failure mode
recall function
OFF None (Normal)
— — — — —
2-time fl ash
2.5 seconds
OFF Outdoor power system
—
Over current protection stop is
continuously performed 3 times within
1 minute after the compressor gets
started. • Reconnect connectors.
• Refer to 11-5. ”How
to check inverter/
compressor”.
• Check stop valve.
○ ○
3-time fl ash
2.5 seconds
OFF Discharge temperature
thermistor 1-time fl ash every
2.5 seconds Thermistor shorts or opens during
compressor running. • Refer to 11-5. ”Check
of outdoor thermistors”
.
Defective outdoor
thermistors can be
identifi ed by checking
the blinking pattern of
LED.
○ ○
Defrost thermistor
Fin temperature thermistor 3-time fl ash 2.5
seconds OFF
P.C. board temperature
thermistor 4-time fl ash 2.5
seconds OFF
4-time fl ash
2.5 seconds
OFF Overcurrent 11-time fl ash 2.5
seconds OFF
12 A ( HC25 ) / 14 A ( HC35 ) current fl ow
into intelligent power module.
• Reconnect compressor
connector.
• Refer to 11-5. ”How
to check inverter/
compressor”.
• Check stop valve.
—
○
Compressor synchronous
abnormality (Compressor
start-up failure protection) 12-time fl ash 2.5
seconds OFF Waveform of compressor current is
distorted. • Reconnect compressor
connector.
• Refer to 11-5. ”How
to check inverter/
compressor”.
—
○
5-time fl ash
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 11-5. ”Check
of LEV”.
—
○
6-time fl ash
2.5 seconds
OFF High pressure
—
Temperature of indoor coil thermistor
exceeds 70°C in HEAT mode. When
defrost thermistor exceeds 70°C in
COOL mode. • Check refrigerant
circuit and refrigerant
amount.
• Check stop valve.
—
○
7-time fl ash
2.5 seconds
OFF Fin temperature/ P.C. board
temperature 7-time fl ash 2.5
seconds OFF Temperature of fi n temperature
thermistor on the inverter P.C.
board exceeds 82°C (
HC25 ) / 83°C
( HC35 ), or temperature of P.C. board
temperature thermistor on the inverter
P.C. board exceeds 81°C (
HC25 ) / 85°
C ( HC35 ).
• Check around outdoor
unit.
• Check outdoor unit air
passage.
• Refer to 11-5. ”Check
of outdoor fan motor”.
—
○
9-time fl ash
2.5 seconds
OFF Nonvolatile memory data 5-time fl ash 2.5
seconds OFF Nonvolatile memory data cannot be
read properly. • Replace the inverter
P.C. board.
○ ○
10-time fl ash
2.5 seconds
OFF Discharge temperature
—
Temperature of discharge temperature
thermistor has been 50°C or less for 20
minutes. • Refer to 11-5. ”Check
of LEV”.
• Check refrigerant
circuit and refrigerant
amount.
—
○
11-time fl ash
2.5 seconds
OFF DC voltage 8-time fl ash 2.5
seconds OFF DC voltage of inverter cannot be
detected normally. • Refer to 11-5. ”How
to check inverter/
compressor”.
—
○
Each phase current of
compressor 9-time fl ash 2.5
seconds OFF Each phase current of compressor
cannot be detected normally.
12-time fl ash
2.5 seconds
OFF Overcurrent Compressor
open-phase 10-time fl ash 2.5
seconds OFF 12 A ( HC25 ) / 14 A ( HC35 ) current fl ow
into intelligent power module (IPM).
When the open-phase operation of
compressor is detected. When the
interphase short out occurs in the
output of the intelligent power module
(IPM). When the compressor winding
shorts out.
• Reconnect compressor
connector.
• Refer to 11-5. ”How
to check inverter/
compressor”.
—
○
14-time fl ash
2.5 seconds
OFF Stop valve (Closed valve) 14-time fl ash 2.5
seconds OFF Closed valve is detected by compressor
current. • Check stop valve.
○ ○
NOTE : Blinking patterns of this mode differ from the ones of Troubleshooting check table (11-3.).