Service manual

43
1. Troubleshooting check table
Operation Indicator
flashing
· Flashing of the OPERATION INDICATOR lamp (on the left-hand side)
indicates possible abnormalities.
· The OPERATION INDICATOR lamp (on the left-hand side) is lighted during
normal operation.
• The following indication applies regardless of shape of the indicatior.
· Flashing of the operation indicator lamp (on the left-hand side) indicates possible abnormalities.
· The operation indicator lamp (on the left-hand side) is lighted during normal operation.
No.
1
2
3
5
6
7
Symptom
Operation indicator lamp Abnormal point Detection method Checkpoint
Outdoor unit
does not
operate.
repeated flashes
every 0.5 seconds
1-time flash
2.5 seconds OFF
2-time flash
2.5 seconds OFF
5-time flash
2.5 seconds OFF
Mis-Wiring
Serial signal
Outdoor power
system
6-time flash
2.5 seconds OFF
Outdoor
thermistors
7-time flash
2.5 seconds OFF
Outdoor control
system
Indoor coil
thermistor
Auxiliary indoor
coil thermistor
Room
temperature
thermistor
When the unit operates by the remote controller or
emergency operation switch at 3 minutes after the main
power supply is turned on.
3 minutes after power supply turns ON, when serial signal is
not received.
When indoor electronic control P.C. board does not
receive serial signals from outdoor unit for 4 to 5
seconds,
Indoor electronic control P.C. board constantly
detects resistance every 8 seconds.
When thermistor shorts or opens.
When compressor has stopped due to overcurrent
protection or start-up failure protection 3 times in a
row within 1 minute after start-up.
<Thermistor short>
Thermistors are abnormal when they short after
compressor start-up.
<Thermistor open>
Thermistors are abnormal when they open after
compressor start-up.
Discharge temperature thermistor is abnormal when
open circuit is detected more than 10 minutes after
compressor start-up.
Defrost thermistor is abnormal when open circuit is
detected more than 1 minutes after compressor
start-up.
When nonvolatile memory data cannot be read properly
on outdoor control P.C. board, outdoor unit stops and
restarts 3 minutes later.
· Shortage of
refrigerant
· Outdoor electronic
control P.C. board
Refer to J "Check
of outdoor
thermistors" on
page 51.
Refer to the
characteristics of main
indoor coil thermistor,
sub indoor coil
thermistor, and room
temperature thermistor
on page 56 or 57.
Refer to A "How to
check inverter/
compressor" on page
47.
Replace outdoor
electronic control P.C.
board.
Refer to 'Checking
serial signal error' on
page 55.
4
3-time flash
2.5 seconds OFF
Indoor fan motor
When rotational frequency feedback signal is not
emit during 12-second indoor fan operation.
Refer to G "Check of
indoor fan motor" on
page 49.
Indoor fan
motor repeats
12 seconds
ON and 3
minutes OFF.
When the
indoor fan
motor breaks,
the fan keeps
stopping.
Outdoor unit
does not
operate.
When the indoor unit has started operation and the above detection method has detected an abnormality (the first
detection after the power ON), the indoor electronic control P.C. board turns OFF the indoor fan motor with the
OPERATION INDICATOR lamp flashing.
OB297--2.qxp 04.2.4 4:21 PM Page 43