24
D 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 the emergency operation switch.
Is serial signal error indicated 6 minutes later?
Yes
• Reinstall either the unit or the light away from each other.
•
Attach a filter on remote control receiving section of the
indoor unit.
No
Turn the power supply OFF.
Is there rated voltage in the power supply?
Yes
No
Check for incorrect indoor-outdoor connecting wiring.
Check the power supply.
Is there rated voltage between outdoor terminal block S1 and S2?
No
Yes
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 multimeter 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 CN10A
and GND with multimeter probes and
start the emergency operation.
During the emergency opera-
tion, does DC (2V or less) occur
for 2 seconds between CN10A
and GND on the indoor elec-
tronic control P.C. board?
No
Does the indoor OPERATION
INDICATOR lamp (upper) 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 (6V or more) occur
between indoor terminal block S2
and S3?
Yes
Replace the outdoor inverter P.C. board. *1
No
Turn the power supply OFF.
Replace the indoor power P.C.
board.
Start the emergency operation.
No
Yes
Repair completed.
Does DC (20V or more) occur
between indoor terminal block S2
and S3 ?
No
Yes
Replace the outdoor inverter P.C. board. *1
Replace the indoor electronic
control P.C. board.
*1.
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. *1
Turn the power supply ON.
Does the indoor OPERATION
INDICATOR lamp (upper) blink
continuously 6 minutes after the
emergency operation starts?
Yes
No
Turn the power supply ON.
No
MUZ Type
OBH905
