Service manual

31
No. Symptom LED indication
Abnormal point/
Condition
Condition Correspondence
1
Outdoor unit
does not op-
erate.
1-time ash every
2.5 seconds
Outdoor power sys-
tem
Overcurrent protection stop is continuously performed 3 times
within 1 minute after the compressor gets started.
Reconnect connector of compres-
sor.
Refer to 11-5.a "How to check in-
verter/compressor".
Check stop valve.
2
Outdoor thermistors Discharge temperature thermistor, n temperature thermistor,
defrost thermistor, P.C. board temperature thermistor, outdoor
heat exchanger temperature thermistor or ambient tempera-
ture thermistor shorts or opens during compressor running.
Refer to 11-5.g "Check of outdoor
thermistors".
3
Outdoor control sys-
tem
Nonvolatile memory data cannot be read properly.
(The upper lamp of OPERATION INDICATOR lamp of the in-
door unit lights up or ashes 7-time.)
Replace inverter P.C. board.
4
6-time ash
2.5 seconds OFF
Serial signal The communication fails between the indoor and outdoor unit
for 3 minutes.
Refer to 11-5. m"How to check mis-
wiring and serial signal error.
5
11-time ash
2.5 seconds OFF
Stop valve/
Closed valve
Closed valve is detected by compressor current. Check stop valve.
6
14-time ash
2.5 seconds OFF
Outdoor unit
(Other abnormality)
Outdoor unit is defective. Refer to 11-2.1. "Flow chart of the
detailed outdoor unit failure mode
recall function".
7
'Outdoor unit
stops and
restarts 3
minutes later'
is repeated.
2-time ash
2.5 seconds OFF
Overcurrent protec-
tion
Large current ows into intelligent power module. Reconnect connector of compres-
sor.
Refer to 11-5. a"How to check in-
verter/compressor".
Check stop valve.
8
3-time ash
2.5 seconds OFF
Discharge tempera-
ture overheat protec-
tion
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 refrig-
erant amount.
Refer to 11-5. k"Check of LEV".
9
4-time ash
2.5 seconds OFF
Fin temperature
/P.C. board tem-
perature thermistor
overheat protection
Temperature of n temperature thermistor on the heat sink
exceeds 75 ~ 80°C or temperature of P.C. board temperature
thermistor on the inverter P.C.board exceeds 70 ~ 75°C.
Check around outdoor unit.
Check outdoor unit air passage.
Refer to 11-5. i"Check of outdoor
fan motor".
10
5-time ash
2.5 seconds OFF
High pressure pro-
tection
Indoor coil thermistor exceeds 70°C in HEAT mode. Defrost
thermistor exceeds 70°C in COOL mode.
Check refrigerant circuit and refrig-
erant amount.
Check stop valve.
11
8-time ash
2.5 seconds OFF
Compressor syn-
chronous abnormal-
ity
The waveform of compressor current is distorted. Reconnect connector of compres-
sor.
Refer to 11-5. a"How to check in-
verter/compressor".
12
10-time ash
2.5 seconds OFF
Outdoor fan motor Outdoor fan has stopped 3 times in a row within 30 seconds
after outdoor fan start-up.
Refer to 11-5. i"Check of outdoor
fan motor.
Refer to 11-5. l"Check of inverter
P.C. board.
13
12-time ash
2.5 seconds OFF
Each phase current
of compressor
Each phase current of compressor cannot be detected nor-
mally.
Refer to 11-5. a"How to check in-
verter/compressor".
14
13-time ash
2.5 seconds OFF
DC voltage DC voltage of inverter cannot be detected normally. Refer to 11-5. a"How to check in-
verter/compressor".
15
Outdoor unit
operates.
1-time ash
2.5 seconds OFF
Frequency drop by
current protection
Current from power outlet is nearing breaker capacity.
PFC module stops due to overcurrent.
The unit is normal, but check the
following.
Check if indoor lters are clogged.
Check if refrigerant is short.
Check if indoor/outdoor unit air cir-
culation is short cycled.
16
3-time ash
2.5 seconds OFF
Frequency drop by
high pressure pro-
tection
Temperature of indoor coil thermistor exceeds 55°C in HEAT
mode, compressor frequency lowers.
Frequency drop by
defrosting in COOL
mode
Indoor coil thermistor reads 8°C or less in COOL mode, com-
pressor frequency lowers.
17
4-time ash
2.5 seconds OFF
Frequency drop by
discharge tempera-
ture protection
Temperature of discharge temperature thermistor exceeds
111°C, compressor frequency lowers.
Check refrigerant circuit and refrig-
erant amount.
Refer to 11-5. k"Check of LEV".
Refer to 11-5. g"Check of outdoor
thermistors".
18
Outdoor unit
operates.
7-time ash
2.5 seconds OFF
Low discharge tem-
perature protection
Temperature of discharge temperature thermistor has been
50°C or less for 20 minutes.
Refer to 11-5. k"Check of LEV".
Check refrigerant circuit and refrig-
erant amount.
19
8-time ash
2.5 seconds OFF
Zero cross detecting
circuit
Zero cross signal for PAM control cannot be detected. This is not malfunction. PAM pro-
tection will be activated in the fol-
lowing cases:
1 Instantaneous power voltage
drop. (Short time power failure)
2 When the power supply voltage
is high.
20
9-time ash
2.5 seconds OFF
Inverter check mode The connector of compressor is disconnected, inverter check
mode starts.
Check if the connector of the com-
pressor is correctly connected.
Refer to 11-5. a"How to check
inverter/compressor".
NOTE: 1. The location of LED is illustrated at the right gure. Refer to 11-6-3.
2. LED is lighted during normal operation.
The ashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the ashing frequency is “2”.
ON
OFF
2.5-second OFF
2.5-second OFF
0.5-second ON
0.5-second ON
Inverter P.C. board
LED
Flashing
SUZ-KA71VA2.TH
OCH472A