38
D How to check miswiring and serial signal error
MUZ-EF Type
• 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.
• Attach a
fi
lter
on remote
control receiv-
ing 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.
A
Is there rated voltage between outdoor terminal block S1 and S2?
No
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
Turn the main power supply
OFF.
Turn the main power supply
ON.
Wait for 2 or more minutes after the main power sup-
ply is turned ON. Touch CN202 and JPG with tester
probes and start the emergency operation.
During the emergency operation,
does DC (2V or more) occur for 2
seconds between CN202 and
JPG on the indoor electronic control
P.C. board?
No
Does the indoor OPERATION
INDICATOR lamp (left) 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
Con
fi
rm 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 main 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 main power supply is turned OFF.
Perform the procedure after 3 minutes.
Replace the outdoor inverter P.C. board. 1
Turn the main power supply ON.
Does the indoor OPERATION
INDICATOR lamp (left) blink
continuously 6 minutes after the
emergency operation starts?
Yes
No
Turn the main power supply ON.
B
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 11-2.1 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
OBH589G
