Mitsubishi SUZ-KA35VA Service Manual page 79

How to check miswiring and serial signal error (when outdoor unit does not work)
O
(For wired remote controller use model)
As for indoor unit.
Inverter P.C.board
(Parts side)
LED
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-contro
lled lighting
Is serial signal
No
equipment.
error indicated
· Attach a filter
6 minutes later?
on receiving
Yes
section of the
indoor unit.
B
OC322G
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 POWER 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?
Yes
Serial signal error display
POWER lamp blinks.
A
Turn OFF the power supply.
Check once more if the indoor/outdoor
B
connecting wire is not mis-wiring.
Short-circuit outdoor terminal block is S2
and S3.
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"?
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.
79
[SUZ-KA25/35VA(H).TH]
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?
No
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.
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. 2
or not
2 Be careful of the residual
lighted)
voltage of smoothing capacitor.
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?
No
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
No
Yes
Make them sure.
Replace the
Yes
indoor/outdoor
connecting wire.
Replace the
Yes
indoor/outdoor
connecting wire.