42
Turn OFF the power supply.
Is there rated voltage in the power supply?
Yes
No
Turn ON the power supply.
Check the power supply.
Is there rated voltage between outdoor terminal block S1 and S2?
No
Check the wiring.
Press the emergency operation switch once.
Does the indoor POWER lamp light up?
<Confirmation of the power to the indoor unit>
Does the LED on the outdoor control P.C. board
repeat "3.6-second-OFF and 0.8-second-ON
quick blinking"?
Is there amplitude of 10 to 20 V DC between
outdoor terminal block S2 and S3?
<Confirmation of serial signal>
Is there any error of the indoor/
outdoor connecting wire, such
as the damage of the wire,
intermediate connection, poor
contact to the terminal block?
Is there rated voltage between indoor terminal
block S1 and S2?
<Confirmation of power voltage>
Yes
Yes
Yes
Yes
Yes
No
No
Is serial signal error indicated 6 minutes later?
Is serial signal error indicated 6 minutes later?
Yes
No
No
No
No
Yes
No
(Lit or
not lit)
Is there any miswiring,
poor contact, or wire
disconnection of the
indoor/outdoor connect-
ing wire?
Yes Correct them.
• The unit is normal.
No
• Turn OFF inverter-controlled lighting equipment.
• Turn OFF the power supply and then turn ON again.
• Press the emergency operation switch.
• Turn OFF the power supply.
• Check once more if the indoor/outdoor connecting
wire is not miswiring.
• Remove the indoor/outdoor connecting wire from
outdoor terminal block S3.
• Short-circuit outdoor terminal block S2 and S3.*1
*1 Miswiring may damage indoor electronic control
P.C. board during the operation.
Be sure to confirm the wiring is correct before the
operation starts.
*2 Be careful of the residual voltage of smoothing
capacitor.
Be sure to release the failure-mode recall function after checking.
LED indication
for communication status
Communication status is indicated by the
LED.
Unit status
Blinking: Normal communication
Lit:
Abnormal communication or
not connected
Pattern 1 and 2 is repeatedly displayed
alternately. Each pattern is displayed for
10 seconds.
NOTE:
"Lit" in the table below does not
indicate abnormal communication.
Turn ON the power supply.
• Turn OFF the power supply.
• Remove the bridge between outdoor terminal block
S2 and S3.
• Turn ON the power supply.
Yes
MXZ Type
Replace the indoor electronic control P.C. board.
Replace the outdoor control P.C. board. *2
Replace the
indoor/outdoor
connecting wire.
Outdoor control P.C. board
Blinking
LED1 LED2 LED3
LED 1
LED 3
LED 2
Pattern
1
2
3
Unit B
status
Unit C
status
Unit A
status
Unit D
status
Unit E
status
Not lit
Lit
Blinking
OBH902A