Mitsubishi Electric MUZ-HA VF Series Service Manual page 39

MXZ Type
HR25/35/42/50
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.
Outdoor control P.C. board
LED1 LED2 LED3
Blinking
Pattern LED 1 LED 2 LED 3
Unit A Unit B
Lit
1
status
status
Unit C
Unit D
Not lit
2
status status
Unit E
3
Blinking
status
OBH822H
Turn OFF the power supply.
Is there rated voltage in the power supply?
Yes
Turn ON the power supply.
Is there rated voltage between outdoor terminal
block S1 and S2?
Yes
Press the emergency operation switch once.
Does the upper lamp of OPERATION
INDICATOR lamp on the indoor unit light up?
<Confirmation of the power to the indoor unit>
Yes
Is serial signal error indicated 6 minutes
later?
Yes
• Turn OFF inverter-controlled lighting equipment.
• Turn OFF the power supply and then turn ON again.
• Press the emergency operation switch.
Is serial signal error indicated 6 minutes
later?
Yes
Turn OFF the power supply.
Check once more if the indoor/outdoor connecting
wire is not miswiring.
Bridge the outdoor terminal block S2 and S3. *1
Turn ON the power supply.
Does the LED on the outdoor control P.C. board repeat
"3.6-second-OFF and 0.8-second-ON quick blinking"?
Yes
Turn OFF the power supply. Remove the bridge
between outdoor terminal block S2 and S3. Turn ON
the power supply. Is there amplitude of 10 to 20 V
DC between outdoor terminal block S2 and S3?
<Confirmation of serial signal>
Yes
Is there rated voltage between outdoor terminal
block S1 and S2?
<Confirmation of power voltage>
Yes
Replace the Indoor electronic control P.C. board.
Be sure to release the failure-mode recall function after checking.
Check the power supply.
No
Check the wiring.
No
No
Is there any miswiring,
poor contact, or wire
disconnection of the
No
indoor/outdoor connect-
ing wire?
No
• Reinstall either the unit or the light away
from each other.
• Attach a filter on remote control receiving
No
section of the indoor unit.
*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.
Replace the inverter P.C. board.
No
2. Be careful of the residual voltage of smooth-
*
ing capacitor.
No
Is there any error of the indoor/outdoor
connecting wire, such as the damage
of the wire, intermediate connection,
No
poor contact to the terminal block?
39
Correct them.
Yes
2
*
Replace the
indoor/outdoor
Yes
connecting wire.
No