27
OCH688A
M How to check miswiring and serial signal error
• Turn OFF inverter-controlled lighting
equipment.
• Turn OFF the power supply and then
turn ON again.
• Press 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.
•
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on remote
control receiv-
ing section
of the indoor
unit.
No
Turn OFF the power supply.
Is there rated voltage in the power supply?
Yes
No
Turn ON the power supply.
Check the power supply.
Is there rated voltage between outdoor terminal block S1 and S2?
No
Check the wiring.
Press EMERGENCY OPERATION switch once.
Does the OPERATION INDICATOR lamp light
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unit>
Yes
No
Is serial signal error indicated 6 minutes
later?
Yes
No
Is there any miswiring,
poor contact, or wire
disconnection of the
indoor/outdoor connect-
ing wire?
Yes
Correct them.
No
A
Turn OFF the power supply.
Check once more if the indoor/outdoor
connecting wire is not miswiring.
Bridge the outdoor terminal block S2 and
S3. 1
B
1. Miswiring may damage indoor electronic control P.C.
board during the operation.
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-
tion starts.
Turn ON the power supply.
Does the LED on the inverter P.C. board or the outdoor electronic control P.C.
board repeat "3.6-second-OFF and 0.8-second-ON quick blinking"? 3
Yes
KA24/30/36
KA18
No
(Lighted
or not
lighted)
Replace the inverter P.C. board or the outdoor
electronic control P.C. board. 2
2. Be careful of the residual voltage of smoothing
capacitor.
Turn OFF the power supply.
Remove the bridge between outdoor terminal block S2 and S3.
Yes
3. Be sure to check this within 3 minutes after turning ON.
After 3 minutes, LED blinks 6 times. Even when the
inverter P.C. board or the outdoor electronic control P.C.
board is normal, LED blinks 6 times after 3 minutes.
(Except for outdoor unit of multi system type)
Is the bus-bar voltage of the inverter P.C. board or the outdoor electronic control P.C. board normal? (Refer
to "TEST POINT DIAGRAM AND VOLTAGE" in the outdoor service manual.)
No
Yes
Replace the indoor electronic control P.C. board.
Turn on the power supply.
Is there amplitude of 10 to 20 VDC between the indoor terminal block
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Yes
Is there 2 VDC or less between CN10A
(+)
and GND (-) on the indoor electronic control
P.C. board?
No
Yes
Is there 2 VDC or less between
CN10A (+) and GND (-) on
the indoor electronic control P.C.
board?
Is there 2 VDC or less between
CN10A
(+) and GND (-) on
the indoor electronic control P.C.
board?
Replace the indoor elec-
tronic control P.C. board.
No
Yes
No
Yes
No
Replace the indoor power
P.C. board.
