Mitsubishi Electric SUZ-KA25VA Technical & Service Manual page 74

• When unit cannot operate neither by the remote controller.
Indoor unit does not operate.
• Outdoor unit does not operate.
R R How to check mis-wiring and serial signal error (when outdoor unit does not work)
(For wired remote controller use model)
Outdoor electronic control P.C. board
(Parts side)
LED2 LED1
Blinking
A
· Turn OFF inverter-controlled lighting
equipment.
· Turn OFF the power supply and then
turn ON it again.
· Press TEST button twice.
· Reinstall the
unit apart from
inverter-
controlled
Is serial signal
No
lighting
error indicated
equipment.
6 minutes later?
· Attach a filter
Yes
on receiving
section of the
B
indoor unit.
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 TEST button twice.
Does the left lamp of OPERATION INDICATOR
lamp on remote controller light up?
<Confirmation of the power to the indoor unit>
Yes
Is the self-check of the remote controller
displayed 6 minutes after?
Serial signal error display
Yes
The left lamp of
OPERATION INDICATOR
lamp blinks.
A
Turn OFF the power supply.
Check once more if the indoor/outdoor
connecting wire is not mis-wiring.
B
Short-circuit outdoor terminal block is S2
and S3.
W 1
Turn ON the power supply.
Does the LED on the inverter P.C. board
or the outdoor electronic control P.C.board
repeat "3.6-second-OFF and 0.8-second-
quick blinking"? W 3
Yes
Turn OFF the power supply.
Remove the short-circuit between
outdoor terminal block S2 and S3.
Turn ON the power supply.
Is there amplitude of 10 to 20V DC
between outdoor terminal block S2
and S3? <Confirmation of serial
signal>
Yes
Is there rated voltage between
indoor 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.
[SUZ-KA50VA .TH SUZ-KA60VA
(1)
No
Check the power
supply.
No
Check the wiring.
No
Is there any mis-
wiring, poor contact,
No
or wire disconnection
of the
indoor/outdoor
connecting wire?
W 1. Mis-wiring may damage indoor electronic control
P.C. board during the operation.
Be sure to confirm the wiring is correct before the
operation starts.
W 3.Be sure to check this within 3 minutes after turning
ON. After 3 minutes, LED blinks 6 times. Even when
the inverter P.C.board or the outdoor electronic control
P.C.board is normal, LED blinks 6 times after 3 minutes.
Replace the inverter P.C. board
No
or the outdoor electronic control
(Lighted P.C.board. W 2
or OFF)
W 2 Be careful to the residual
Is there any error of the
indoor/outdoor connecting wire,
such as the damage of the wire,
intermediate connection, poor
No
contact to the terminal block?
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?
No
74
.TH SUZ-KA71VA
(1)
As for indoor unit.
Yes
Make them sure.
No
voltage of smoothing capacitor.
Replace the
Yes
indoor/outdoor
connecting wire.
No
Replace the
Yes
indoor/outdoor
connecting wire.
No
.TH]
(1)