35
How to check miswiring and serial signal error
When the left lamp of OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second.
Outdoor unit does not operate.
Is there rated voltage of
230V AC in the power
supply?
In 3 minutes after turning ON the
power supply of the outdoor unit, does
the LED on the inverter P.C. board
repeat quick blinking "3.6-second-OFF
and 0.8-second-ON"?
Be sure to check above in 3 minutes
after turning ON. After 3 minutes, LED
blinks 6 times. When the inverter P.C.
board is normal, LED also blinks 6
times after 3 minutes.
Is there any miswiring,
poor contact or wire
disconnection of the
indoor/outdoor
connecting wire?
1. Mis-wiring may damage indoor electronic control
P.C. board during operation.
Be sure to confirm the wiring is correct before the
operation starts.
(Lighting)
No
Yes
No
Yes
Yes
No
Yes
No
Yes
No
2 Be careful of the residual
voltage of smoothing capacitor.
Be sure to release the failure-mode recall function after checking.
No
No
Yes
No
Yes
Yes
Yes
No
Yes
As for outdoor unit, refer to outdoor unit service manual.
Inverter P.C. board
(Parts side)
LED
Blinking
Turn OFF the power supply.
Turn ON the power supply.
Is there 230V AC between
outdoor terminal block S1 and
S2?
Does the left lamp of OPERATION INDICATOR
lamp light up? <Confirmation of the power
supply to the indoor unit>
Press EMERGENCY OPERATION switch once.
Check the power
supply.
Is the serial signal error indicated 6 minutes later?
A
Turn OFF the power supply.
Check once again if the indoor/outdoor
connecting wire is not wrongly connected.
Short-circuit the outdoor terminal block S2
and S3.
1
B
Turn ON the power supply of the outdoor unit.
Check the wiring.
Correct the wiring.
Remove the short-circuit between
outdoor terminal block S2 and S3.
Is there amplitude of 10 to 20V DC
between outdoor terminal block S2
and S3? <Confirmation of serial
signal>
Is there 230V AC between outdoor
terminal block S1 and S2?
<Confirmation of power voltage>
Replace the indoor electronic control P.C. board.
Replace the inverter
P.C. board.
2
Is there any error of the
indoor/outdoor connecting wire,
such as the damage of the wire,
intermediate connection, poor
contact to the terminal block?
Is there any error of the
indoor/outdoor connecting wire,
such as the damage of the wire,
intermediate connection, poor
contact to the terminal block?
Replace the
indoor/outdoor
connecting.
Replace the
indoor/outdoor
connecting.
Is the serial
signal error
indicated 6
minutes later?
Yes
No
· Turn OFF inverter-controlled lighting
equipment.
· Turn OFF the power supply and then
turn it ON again.
· Press EMERGENCY OPERATION
switch.
B
· Reinstall
either the
unit or the
light away
from each
other.
· Attach a filter
on receiving
section of
the indoor
unit.
A
No
D
OB409E
