Mitsubishi Electric SUZ-KA09NAH2.MX Service Manual page 14

10-2. TROUBLE SHOOTING CHECK TABLE
SUZ-KA09NA(H)2.MX SUZ-KA12NA(H)2.MX SUZ-KA15NA(H)2.MX
LED check
No. Symptoms
code
indication
Outdoor 1-time blink
unit does not every
1
UP
operate. 2.5 seconds
U3 Outdoor thermistors
2
U4
3 FC Outdoor control system
6-time blink
E8
4
2.5 seconds
E9
OFF
11-time
blink
5
UE
2.5 seconds
OFF
16-time PL Outdoor refrigerant
blink
6
2.5 seconds
OFF
'Outdoor unit 2-time blink
stops and 2.5 seconds OFF
7
restarts
3 minutes
3-time blink
later' is
8
2.5 seconds OFF
repeated.
4-time blink
9
2.5 seconds OFF
5-time blink
10
2.5 seconds OFF
8-time blink
11
2.5 seconds OFF
10-time blink
12
2.5 seconds OFF
12-time blink
13
2.5 seconds OFF
13-time blink
14
2.5 seconds OFF
Outdoor unit 1-time blink
15
operates. 2.5 seconds OFF
3-time blink
2.5 seconds OFF
16
4-time blink
17
2.5 seconds OFF
7-time blink
18
2.5 seconds OFF
8-time blink
2.5 seconds OFF
19
9-time blink
2.5 seconds OFF
20
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 blinking frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the blinking frequency is "2".
ON
2.5-second OFF
OFF
OCH699
Abnormal point/ Condition
Overcurrent protection cut-out operates 3 consecutive times
Outdoor power system
within 1 minute after the compressor gets started.
Discharge temperature thermistor shorts, or opens during com-
pressor running.
Fin temperature thermistor, defrost thermistor, P.C. board
temperature thermistor, outdoor heat exchanger
temperature thermistor or ambient temperature thermistor
shorts, or opens during compressor running.
Nonvolatile memory data cannot be read properly.
Serial signal The communication fails between the indoor and outdoor unit for
3 minutes.
Stop valve/Closed valve Closed valve is detected by compressor current.
A closed valve and air trapped in the refrigerant circuit are
detected based on the temperature sensed by the indoor and
system abnormality
outdoor thermistors and the current of the compressor.
Overcurrent protection
Temperature of discharge temperature thermistor exceeds
Discharge temperature
116°C, compressor stops. Compressor can restart if discharge
overheat protection
temperature thermistor reads 100°C or less 3 minutes later.
Fin temperature/P.C. Temperature of fin temperature thermistor on the heat sink
exceeds 72 to 86°C or temperature of P.C. board temperature
board temperature therm-
thermistor on the inverter P.C.board exceeds 72 to 85°C.
istor overheat protection
High pressure protection Indoor coil thermistor exceeds 70°C in HEAT mode. Defrost
thermistor exceeds 70°C in COOL mode.
Compressor synchronous The waveform of compressor current is distorted.
abnormality
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 of inverter cannot be detected normally.
DC voltage
When the input current exceeds approximately
Frequency drop by
7A(KA09)/8A(KA12)/9A(KA15), compressor
current protection
Frequency drop by Temperature of indoor coil thermistor exceeds 131 °F [55 °C] in
HEAT mode, compressor frequency lowers.
high pressure protection
Frequency drop by Indoor coil thermistor reads 46 °F [8 °C] or less in COOL mode,
compressor frequency lowers.
defrosting in COOL mode
Frequency drop by Temperature of discharge temperature thermistor exceeds 232
°F [111 °C], compressor frequency lowers.
discharge temperature
protection
Low discharge tempera- Temperature of discharge temperature thermistor has been 122
°F [50 °C] or less for 20 minutes.
ture protection
PAM protection The overcurrent flows into IGBT (Insulated Gate Biopolar
transistor:TR821) or the bus-bar voltage reaches 320 V or more,
PAM: Pulse Amplitude
PAM stops and restarts.
Modulation
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
Condition
0.5-second ON
14
Remedy
AHow to check inverter/
compressor".
F Check of outdoor thermistors".
abnormality is displayed again.
O
circuit".
AHow to check inverter/
compressor".
kCheck of LEV".
ICheck of outdoor fan motor".
AHow to check inverter/
compressor".
ICheck of outdoor fan motor".
LCheck of inverter P.C. board".
LCheck of inverter P.C. board".
AHow to check inverter/
compressor".
The unit is normal, but check the following.
circulation is short cycled.
kCheck of LEV".
GCheck of outdoor thermistors".
kCheck of LEV".
This is not malfunction. PAM protection
will be activated in the following cases:
1. Instantaneous power voltage
drop. (Short time power failure)
2. When the power supply voltage is high.
correctly connected.
AHow to check
inverter/compressor".
Inverter P.C. board
Blinking
LED