Mitsubishi Electric M Series Manual page 167

M series
MUZ-FD25VA MUZ-GE25VA
MUZ-FD25VABH MUZ-GE25VAH
MUZ-FD35VA MUZ-GE35VA
MUZ-FD35VABH MUZ-GE35VAH
Troubleshooting check table
No. Symptom LED indication
Outdoor unit 1-time flash eve-
1
does not op- ry 2.5 seconds
erate.
2
3
6-time flash
4
2.5 seconds OFF
11-time flash
5
2.5 seconds OFF
14-time flash
6
2.5 seconds OFF
'Outdoor unit 2-time flash
stops and 2.5 seconds OFF
7
restarts 3
minutes later'
3-time flash
is repeated.
2.5 seconds OFF
8
4-time flash
2.5 seconds OFF
9
5-time flash
10
2.5 seconds OFF
8-time flash
2.5 seconds OFF
11
MUZ-FD, MUZ-GE
12 10-time flash
2.5 seconds OFF
12-time flash
13
2.5 seconds OFF
13-time flash
14
2.5 seconds OFF
Outdoor unit 1-time flash
15
operates. 2.5 seconds OFF
3-time flash
2.5 seconds OFF
16
4-time flash
2.5 seconds OFF
17
Outdoor unit 7-time flash
18
operates. 2.5 seconds OFF
8-time flash
2.5 seconds OFF
19
9-time flash
20
2.5 seconds OFF
NOTE: 1. The location of LED is illustrated at the right figure.
2. LED is lighted during normal operation.
The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the flashing frequency is "2".
ON
2.5-second OFF
OFF
MUZ-GE42VA
MUZ-GE42VAH
MUZ-GE50VA
MUZ-GE50VAH
Abnormal point/
Condition
Outdoor power Overcurrent protection stop is continuously performed 3 times within 1 minute after the compressor
system gets started, [or failure of restart of compressor has repeated 24 times (MUZ-HC)].
Outdoor thermistors Discharge temperature thermistor, fin temperature thermistor, defrost thermistor, P.C. board tem-
perature thermistor, outdoor heat exchanger temperature thermistor or ambient temperature ther-
mistor shorts or opens during compressor running.
Outdoor control Nonvolatile memory data cannot be read properly.
system (POWER (MSZ-FD)/the upper (MSZ-GE, MSZ-HC) lamp of OPERATION INDICATOR lamp of the
indoor unit lights up or flashes 7-time.)
Serial signal The communication fails between the indoor and outdoor unit for 3 minutes.
Stop valve/ Closed valve is detected by compressor current.
Closed valve
Outdoor unit Outdoor unit is defective.
(Other abnormality)
Overcurrent protec- Large current flows into intelligent power module.
tion w When overcurrent protection occurs whithin 10 seconds after compressor starts, compressor
restarts after 15 seconds (MUZ-HC).
Discharge tem- Temperature of discharge temperature thermistor exceeds
perature overheat 116°C, compressor stops. Compressor can restart if discharge temperature thermistor reads 100°C
protection or less 3 minutes later.
Fin temperature Temperature of fin temperature thermistor on the heat sink exceeds 75°C~ 80°C (MUZ-FD, MUZ-
/P.C. board tem- GE)/82°C (MUZ-HC25)/83°C (MUZ-HC35) or temperature of P.C. board temperature thermistor on
perature thermistor the inverter P.C. board exceeds 70°C~ 75°C (MUZ-FD,MUZ-GE)/81°C (MUZ-HC25)/85°C (MUZ-
overheat protection HC35).
High pressure pro- Indoor coil thermistor exceeds 70°C in HEAT mode. Defrost thermistor exceeds 70°C in COOL
tection mode.
Compressor syn- The waveform of compressor current is distorted.
chronous abnormal-
ity
Outdoor fan motor Outdoor fan has stopped 3 times in a row within 30 seconds after outdoor fan start-up.
Each phase current Each phase current of compressor cannot be detected normally.
of compressor
DC voltage DC voltage of inverter cannot be detected normally.
Frequency drop by Current from power outlet is nearing breaker capacity.
current protection PFC module stops due to overcurrent. (MUZ-GE60/71)
Frequency drop by Temperature of indoor coil thermistor exceeds 55°C in HEAT mode, compressor frequency lowers.
high pressure pro-
tection
Frequency drop by Indoor coil thermistor reads 8°C or less in COOL mode, compressor frequency lowers.
defrosting in COOL
mode
Frequency drop by Temperature of discharge temperature thermistor exceeds 111°C, compressor frequency lowers.
discharge tempera-
ture protection
Low discharge tem- Temperature of discharge temperature thermistor has been 50°C or less for 20 minutes.
perature protection
MUZ-FD, MUZ- The overcurrent flows into IGBT (Insulated Gate Bipolar transistor: TR821) or the bus-bar voltage
GE25/35/42/50, MUZ-HC reaches 320 V or more, PAM stops and restarts.
PAM protection
PAM: Pulse Ampli-
tude Modulation
MUZ-GE60/71 Zero cross signal for PAM control cannot be detected.
Zero cross detect-
ing circuit
Inverter check The connector of compressor is disconnected, inverter check mode starts.
mode
0.5-second ON
2.5-second OFF
WALL-MOUNTED Inverter Heat Pump
MUZ-GE60VA MUZ-HC25VA
MUZ-GE71VA MUZ-HC35VA
MUZ-HC35VAB
Condition
Inverter P.C. board
0.5-second ON
MUZ-FD,
Flashing →
MUZ-GE25/
LED
35/42/50,
MUZ-HC
MUZ-GE
Flashing 60/71
→
LED
C-165