33
MXY-3G28VA MXY-4G28VA MXY-4G38VA MXY-5G48VA
MXY-3G28VA2 MXY-4G33VA2 MXY-4G38VA2 MXY-5G48VA2
• 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 filter
on remote
control receiv-
ing section
of the indoor
unit.
No
Turn the 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 power supply
and outdoor terminal block S1 and between
the power supply and outdoor terminal block
S2.
Wait for 2 or more minutes after the 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 power supply OFF.
Turn the power supply ON.
Wait for 2 or more minutes after the power supply
is turned ON. Touch CN20A and GND with tester
probes and start the emergency operation.
During the emergency operation,
does DC (2V or less) occur for 2
seconds between CN20A and
GND on the indoor electronic con-
trol P.C. board?
No
Does the indoor operation indica-
tor lamp blink continuously 6
minutes after the emergency
operation starts?
No
Does the outdoor LED light up?
*1
Replace the
indoor electronic
control P.C. board.
Replace the
indoor power P.C.
board.
Yes
Yes
Confirm that the thermostat is OFF
and wiring is not loose.
Does DC (6V or more) occur
between indoor terminal block S2
and S3?
Yes
Replace the outdoor control P.C. board.*2
No
Turn the 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 control P.C. board. *2
Replace the indoor electronic
control P.C. board.
*2
Electric charge may remain immediately
after the power supply is turned OFF.
Perform the procedure after 3 minutes.
Turn the power supply ON.
Does the indoor operation indica-
tor lamp blink continuously 6
minutes after the emergency
operation starts?
Yes
No
No
No
Was the indoor unit ever connected to
the non-low-standby-power model 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
for communication status
Communication status is indicated
by the LED.
Blinking: normal communication
Lighting: abnormal communication or
not connected
Pattern 1 and 2 are repeatedly displayed
alternately. Each pattern is displayed for
15 seconds.
NOTE:
"Lit" in the table below does not
indicate abnormal communication.
Unit status
Outdoor control P.C. board
Blinking
LED1 LED2 LED3
LED 1
LED 3
LED 2
Pattern
1
2
3
(
MXY-5G48VA
)
(
MXY-5G48VA2
)
Unit B
status
Unit C
status
Unit E
status
Unit A
status
Unit D
status
Not lit
Blinking
Lit
*1 LED indication
Outdoor units are low-standby-power models.
Turn the power supply ON.
B
OBH779C
