40
D How to check miswiring and serial signal error
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
MUZ Type
Turn the main 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 main power
supply and outdoor terminal block S1 and
between the main power supply and outdoor
terminal block S2.
Wait for 2 or more minutes after the main 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
No
Does the upper lamp of
OPERATION INDICATOR lamp on
the 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.
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
Replace the indoor electronic control
P.C. board. *1
*1.
Electric charge may remain immediately
after the main power supply is turned OFF.
Perform the procedure after 3 minutes.
Replace the outdoor inverter P.C. board. *1
Yes
Turn the main power supply ON.
No
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 abnor-
mal condition” described in 10-2.1 to clear the error his-
tory. 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
No
• Turn OFF inverter-controlled lighting equipment.
• Turn OFF the power supply and then turn ON again.
• Press the emergency operation switch.
OBH932