31
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
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 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
No
Does the upper lamp of OPERA-
TION 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 (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
*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
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
abnormal condition” described in 10-2.1 to clear the error
history. When the error history is being cleared, the con-
nection 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.
Turn the main power supply ON.
OBH838B
