Mitsubishi Electric SUZ-KA25VA Technical & Service Manual page 57

12-3. Troubleshooting check table
SUZ-KA25VA.TH
SUZ-KA25VAH.TH SUZ-KA35VAH.TH
NOTE 1. The location of LED is illustrated at the right figure. Refer to 12-6-1.
2. LED lights up during normal operation.
No. Symptom LED indication
1-time flash every
Outdoor unit
2.5 seconds
does not
1
operate
2
3
6-time flash
4
2.5 seconds OFF
14-time flash
5 2.5 seconds OFF
2-time flash
'Outdoor unit
2.5 seconds OFF
stops and
6 restarts 3
minutes later'
is repeated
3-time flash
2.5 seconds OFF
7
4-time flash
2.5 seconds OFF
8
5-time flash
2.5 seconds OFF
9
8-time flash
2.5 seconds OFF
10
10-time flash
2.5 seconds OFF
11
12-time flash
12
2.5 seconds OFF
13-time flash
2.5 seconds OFF
13
1-time flash
Outdoor unit
2.5 seconds OFF
14
operates
3-time flash
2.5 seconds OFF
15
4-time flash
2.5 seconds OFF
16
Outdoor unit
7-time flash
operates
17
2.5 seconds OFF
8-time flash
2.5 seconds OFF
18
9-time flash
2.5 seconds OFF
19
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
OFF
SUZ-KA35VA.TH
Abnormal point/ Condition
When it consecutively occurs 3times that the compressor stops
Outdoor power
for overcurrent protection or start-up failure protection within
system
1minute start-up.
When discharge temperature thermistor, fin temperature
Outdoor
thermistors thermistor, defrost thermistor, P.C. board temperature
thermistor or ambient temperature thermistor shorts or opens
during compressor running.
When nonvolatile memory data cannot be read properly,
Outdoor control
compressor stops.
system
When the communication failure between the indoor and
Serial signal
outdoor unit for 3 minutes.
Outdoor unit
When outdoor unit is defective.
(Other abnormality)
Overcurrent When 14A(SUZ-KA25VA(H))/ 24A(SUZ-KA35VA(H)) current
protection flows into intelligent power module.
Discharge When discharge temperature thermistor exceeds 116:,
temperature
compressor stops. Compressor can restart if discharge
overheat temperature thermistor reads 100: or less 3 minutes later.
protection
Fin temperature
When temperature of fin temperature thermistor on the heat
/P.C. board
sink exceeds 83:(SUZ-KA25VA(H))/ 82:(SUZ-KA35VA(H))
temperature
or temperature of P.C. board temperature thermistor exceeds
thermistor 85:(SUZ-KA25VA(H))/ 81:(SUZ-KA35VA(H)), compressor
overheat protection
stops and restarts 3 minutes later.
When indoor coil thermistor exceeds 70: in HEAT mode.
High pressure
When the defrost thermistor exceeds 70: in COOL mode.
protection
Compressor
When the waveform of compressor current is distorted.
synchronous
abnormality
Outdoor fan
When outdoor fan has stopped within 30 seconds 3 times a
row after outdoor fan start-up, unit stops.
Each phase current
When compressor each phase current cannot be detected
of compressor
normally
DC voltage When DC voltage of inverter cannot be detected normally.
Frequency drop by When current from power outlet exceeds 6.1A(SUZ-
current protection
KA25VA(H))/ 9.2A(SUZ-KA35VA(H)), compressor frequency
lowers.
Frequency drop by
When indoor coil thermistor exceeds 55: in HEAT mode,
high pressure
compressor frequency lowers.
protection
Frequency drop by When indoor coil thermistor reads 8: or less in COOL mode,
defrosting in COOL compressor frequency lowers.
mode
Frequency drop by When discharge temperature thermistor exceeds 111:,
discharge compressor frequency lowers.
temperature
protection
Low discharge
When discharge temperature has been 50: or less for 20
temperature
minutes.
protection
When the overcurrent flows into IGBT(Insulated Gate Bipolar
PAM protection
transistor : TR821) or when the bus-bar voltage reaches 320V
or more, PAM stops and restarts.
PAM:
Pulse
Amplitude
Modulation
When the connector of compressor is disconnected, inverter
Inverter check
check mode starts.
mode
2.5-second OFF
Detection method
0.5-second ON
2.5-second OFF
57
Inverter P.C. board (Parts side)
LED
Flashing
Check point
· Check stop valve.
· Reconnect connector of compressor.
· Refer to 12-5.A "How to check
inverter/ compressor".
· Refer to 12-5.G "Check of outdoor
thermistors".
Replace inverter P.C. board.
Refer to 12-5.O "How to check mis-
wiring and serial signal error.
Refer to 12-2-3.
Check [output pattern B]
· Check stop valve.
· Reconnect connector of compressor.
· Refer to 12-5.A "How to check
inverter/compressor".
· Check refrigerant circuit and
refrigerant amount.
· Refer to 12-5.L "Check of LEV".
· Check around outdoor unit.
· Check outdoor unit air passage.
· Refer to 12-5.I "Check of outdoor
fan motor".
· Check refrigerant circuit and
refrigerant amount.
· Check stop valve.
· Reconnect connector of compressor.
· Refer to 12-5.A "How to check
inverter/compressor".
· Refer to 12-5.I "Check of outdoor
fan motor.
· Refer to 12-5.N "Check of inverter
P.C. board.
· Refer to 12-5.A "How to check
inverter/compressor".
· Refer to 12-5.A "How to check
inverter/compressor".
The unit is normal, but check the
following.
· Check if indoor filters are clogged.
· Check if refrigerant is short.
· Check if indoor/outdoor unit air
circulation is short cycled.
· Check refrigerant circuit and
refrigerant amount.
· Refer to 12-5.L "Check of
LEV".
· Refer to 12-5.G "Check of
outdoor thermistors".
· Refer to 12-5.L "Check of LEV".
· Check refrigerant circuit and
refrigerant amount.
This is not malfunction.
PAM protection will be activated in
the following cases;
1Instantaneous power voltage drop
(Short time power failure)
2When the power supply voltage is
high.
Check if the connector of the
compressor is correctly connected.
Refer to 12-5.A "How to check
inverter/ compressor".
0.5-second ON