Mitsubishi Electric SVZ-KP18NA Service Manual page 17

10-2. TROUBLE SHOOTING CHECK TABLE
SUZ-KA09NA
LED
No. Symptoms
indication
Outdoor unit 1-time flash
1
does not op-
every
erate.
2.5 seconds
2
3
6-time flash
2.5 seconds
4
OFF
11-time flash
5
2.5 seconds OFF
'Outdoor unit
2-time flash
stops and
2.5 seconds OFF
restarts 3
6
minutes later'
is repeated.
3-time flash
7
2.5 seconds OFF
4-time flash
2.5 seconds OFF
8
5-time flash
2.5 seconds OFF
9
8-time flash
10
2.5 seconds OFF
10-time flash
11
2.5 seconds OFF
12-time flash
12
2.5 seconds OFF
13-time flash
13
2.5 seconds OFF
Outdoor unit 1-time flash
operates. 2.5 seconds OFF
14
3-time flash
2.5 seconds OFF
15
4-time flash
2.5 seconds OFF
16
7-time flash
2.5 seconds OFF
17
8-time flash
2.5 seconds OFF
18
9-time flash
2.5 seconds OFF
19
NOTE: 1. The location of LED is illustrated at the right figure. Refer to "10-6. TEST POINT DIAGRAM".
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
TCH022
SUZ-KA12NA
check
Abnormal point/ Condition
code
Overcurrent protection cut-out operates 3 consecutive times
Outdoor power sys-
UP
tem
within 1 minute after the compressor gets started.
Outdoor thermistors Discharge temperature thermistor shorts, or opens during
U3
compressor running.
Fin temperature thermistor,
temperature thermistor, outdoor heat exchanger temperature
U4
thermistor or ambient temperature thermistor shorts, or opens
during compressor running.
FC
Outdoor control system Nonvolatile memory data cannot be read properly.
E8 Serial signal The communication fails between the indoor and outdoor unit
/ for 3 minutes.
E9
Stop valve/
Closed valve is detected by compressor current.
UE
Closed valve
Large current flows into intelligent power module.
Overcurrent protec-
tion
Discharge tempera- Temperature of discharge temperature thermistor exceeds
ture overheat pro- 116°C, compressor stops. Compressor can restart if discharge
tection temperature thermistor reads 100°C or less 3 minutes later.
Fin temperature Temperature of fin temperature thermistor on the heat sink
/P.C. board tem- exceeds 72 to 86°C or temperature of P.C. board temperature
perature thermistor thermistor on the inverter P.C.board exceeds 72 to 85°C.
overheat protection
High pressure pro- Indoor coil thermistor exceeds 70°C in HEAT mode. Defrost
tection thermistor exceeds 70°C in COOL 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 nor-
of compressor mally.
DC voltage DC voltage of inverter cannot be detected normally.
Frequency drop by
When the input current exceeds approximately 7A(KA09)/
current protection
8A(KA12)/14A(KA15)/16A(KA18), compressor
frequency lowers.
Frequency drop by
Temperature of indoor coil thermistor exceeds 131 °F [55 °C]
high pressure pro-
in HEAT mode, compressor frequency lowers.
tection
Frequency drop by Indoor coil thermistor reads 46 °F [8 °C] or less in COOL
defrosting in COOL
mode, compressor frequency lowers.
mode
Frequency drop by
Temperature of discharge temperature thermistor exceeds
discharge tempera-
232 °F [111 °C], compressor frequency lowers.
ture protection
Low discharge tem- Temperature of discharge temperature thermistor has been
perature protection 122 °F [50 °C] or less for 20 minutes.
The overcurrent flows into IGBT (Insulated Gate Biopolar tran-
PAM protection
sistor: TR821) or the bus-bar voltage reaches 320 V or more,
PAM: Pulse Ampli-
tude Modulation PAM stops and restarts.
Zero cross detecting Zero cross signal for PAM control cannot be detected.
circuit
Inverter check mode The connector of compressor is disconnected, inverter check
mode starts.
0.5-second ON
2.5-second OFF
SUZ-KA15NA
Condition
defrost thermistor, P.C. board
0.5-second ON
17
SUZ-KA18NA
• Reconnect connector of compressor.
• Refer to "10-5. How to check in-
verter/compressor".
• Check stop valve.
• Refer to "10-5.F Check of outdoor
thermistors".
• Replace inverter P.C. board.
• Check indoor/outdoor connecting wire.
•
Replace indoor or outdoor P.C.
board if abnormality is displayed
again.
• Check stop valve.
• Reconnect connector of compressor.
• Refer to "10-5.
verter/compressor".
• Check stop valve.
• Check refrigerant circuit and refrig-
erant amount.
• Refer to "10-5. k Check of LEV".
• Check around outdoor unit.
• Check outdoor unit air passage.
• Refer to "10-5. Check of outdoor
fan motor".
• Check refrigerant circuit and refrig-
erant amount.
• Check stop valve.
• Reconnect connector of compressor.
• Refer to "10-5.
verter/compressor".
• Refer to "10-5. Check of outdoor
fan motor.
Refer to "10-5.
•
P.C. board.
•
Refer to "10-5
verter/compressor".
•
Refer to "10-5
verter/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 refrig-
erant amount.
• Refer to "10-5.
• Refer to "10-5.
thermistors".
• Refer to "10-5.
• Check refrigerant circuit and refrig-
erant amount.
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.
•
Check if the connector of the com-
pressor is correctly connected.
• Refer to "10-5.
inverter/compressor".
Inverter P.C. board
Flashing
Remedy
How to check in-
I
How to check in-
I
Check of inverter
L
How to check in-
L
.
How to check in-
A
.
Check of LEV".
K
Check of outdoor
G
Check of LEV".
K
How to check
LED