32
D How to check miswiring and serial signal error
MUZ Type
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?
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 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?
No
Does the indoor upper lamp of OPERATION
INDICATOR lamp blink continuously 6 minutes
after the emergency operation starts?
No
Does the outdoor LED light up?
Replace the indoor electronic control P.C.
board.
Yes
Does the outdoor LED blink 6 times?
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.
*1
No
Replace the indoor electronic control P.C. board.
*1
Electric charge may remain immediately after
the power supply is turned OFF.
Perform the procedure 3 minutes after the
power off operation.
Replace the outdoor inverter P.C. board.
*1
Yes
No
Was the indoor unit ever connected to the Multi
(MXZ) series and operated (turned on)?
The connection information to the Multi series is stored in
the indoor unit. Refer to “Deleting the memorized abnormal
condition” described in 10-2.1 to clear the error history. When
the error history is being cleared, the connection information
also will be initialized. The indoor unit will be compatible with a
low-standby-power model after initialization.
OK
Yes
Turn ON the power supply.
• Turn OFF inverter-controlled lighting equipment.
• Turn OFF the power supply and then turn ON again.
• Press 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
No
No
Yes
Yes
OBH864
