47
M How to check miswiring and serial signal error
Turn the power supply OFF.
Is there rated voltage of 230 V AC in the
power supply?
Yes
No
Press the emergency operation switch once.
Check the power supply.
No
Check for miswiring, broken wires, and loose
wire connection between the power supply and
outdoor terminal block S1 and between the
power supply and outdoor terminal block S2.
Wait for 2 or more minutes after the power supply is turned on.
Touch S2 and S3 with tester probes and start the emergency operation.
When the emergency operation starts, does the rated voltage occur for 2
seconds between indoor terminal block S2 and S3?
Yes
Turn the power supply OFF.
Turn the power supply ON.
Wait for 2 or more minutes after the
power supply is turned ON. Touch
CN202 and GND with tester probes
and start the emergency operation.
During the emergency opera-
tion, does DC (2V or less) occur
for 2 seconds between CN202
and GND on the indoor power
P.C. board?
Does the left lamp of OPERATION
INDICATOR lamp on indoor unit
blink continuously 6 minutes after
the emergency operation starts?
No
Does the outdoor LED light up?
Replace the indoor
electronic control
P.C. board.
Replace the
indoor power P.C.
board.
Yes
Yes
Does the outdoor LED blink 6
times?
Yes
Confirm that the thermostat is OFF
and wiring is not loose.
No
Does DC (6 V or more) occur
between indoor terminal block S2
and S3?
Yes
Replace the outdoor inverter P.C. board.*2
No
Turn the power supply OFF.
Replace the indoor power P.C.
board.
Start the emergency operation.
No
Yes
Repair completed.
Does DC (20 V or more) occur
between indoor terminal block S2
and S3?
No
Yes
Replace the outdoor inverter P.C. board.
Replace the indoor electronic
control P.C. board.
*2 Electric charge may remain immediately
after the power supply is turned OFF.
Perform the procedure after 3 minutes.
Replace the outdoor inverter P.C. board.*2
Turn the power supply ON.
Does the left lamp of OPERATION
INDICATOR lamp on indoor unit
blink continuously 6 minutes after
the emergency operation starts?
Yes
No
No
Turn the power supply ON.
Is there 230 V AC between outdoor terminal
block S1 and S2?
• Turn OFF inverter-controlled lighting
equipment.
• Turn OFF the power supply and then
turn ON again.
• Press the emergency operation switch.
A
Is serial signal
error indicated 6
minutes later?
B
Yes
• Reinstall
either the unit
or the light
away from
each other.
•
Attach a filter
on remote
control receiv-
ing section
of the indoor
unit.
No
A
Turn the power supply ON.
Does the left lamp of OPERATION INDICATOR lamp light up?
<Confirmation of the power supply to the indoor unit>
Yes
Is the serial signal error indicated 6 minutes
later?
No
Is there any miswiring, poor con-
tact, or wire disconnection of the
indoor/outdoor connecting wire?
No
Correct them.
Yes
No
Yes
No
Turn OFF the power supply. Check once again if the indoor/out-
door connecting wire is not wrongly connected.
Short-circuit the outdoor terminal block S2 and S3. *1
B
Yes
*1 Miswiring may damage indoor electron-
ic control P.C. board during operation.
Be sure to confirm the wiring is correct
before theoperation starts.
OBH895
