Mitsubishi Electric Mr.Slim MSY-D30NA, Service Manual

Page: 185 / 214

59
M How to check miswiring and serial signal error
• 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 fi lter
on remote
control receiv-
ing section
of the indoor
unit.
No
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 EMERGENCY OPERATION switch once.
Does the OPERATION INDICATOR lamp light
up? <Con
fi rmation of the power to the indoor
unit>
Yes
No
Is serial signal error indicated 6 minutes later?
Yes
No
Is there any miswiring,
poor contact, or wire
disconnection of the
indoor/outdoor connect-
ing wire?
Yes
Correct them.
No
A
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
B
1. Miswiring may damage indoor electronic control P.C.
board during the operation.
Be sure to con
fi rm the wiring is correct before the opera-
tion starts.
Turn ON the power supply.
Does the LED on the inverter P.C. board repeat "3.6-second-OFF and 0.8-sec-
ond-ON quick blinking"? 3
Yes
No
(Lighted
or not
lighted)
Replace the inverter P.C. board . 2
2. Be careful of the residual voltage of smoothing
capacitor.
Yes
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.
Is the bus-bar voltage of the inverter P.C. board normal? (Refer to "TEST POINT DIAGRAM AND
VOLTAGE" in this manual.)
Yes
No
Check of power supply.
(Refer to 10-5. .)
Replace the indoor elec-
tronic control P.C. board.
Turn OFF the power supply.
Remove the bridge between outdoor terminal block S2 and S3.
OBH549G