Mitsubishi Electric MUZ-HA VF Series Service Manual page 37

D How to check miswiring and serial signal error
HR25/35/42/50
Is the bus-bar voltage of the inverter P.C. board normal? (Refer to "TEST POINT DIAGRAM AND
VOLTAGE" in the outdoor service manual.)
Does the LED on the inverter P.C. board repeat "3.6-second-OFF and
0.8-second-ON quick blinking"? *3
OBH822H
Turn OFF the power supply.
Is there rated voltage in the power supply?
Turn ON the power supply.
Is there rated voltage between outdoor terminal block S1 and S2?
Press the emergency operation switch once.
Does the OPERATION INDICATOR lamp light
up? <Confirmation of the power to the indoor
unit>
Is serial signal error indicated 6 minutes
later?
• 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?
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.
Turn OFF the power supply.
Remove the bridge between outdoor terminal block S2 and S3.
Replace the indoor electronic control P.C. board.
No
Yes
Yes
No
Yes
Is there any miswiring,
poor contact, or wire
disconnection of the
No
indoor/outdoor connect-
Yes
ing wire?
• Reinstall either the unit or the light away from
each other.
No
• Attach a filter on remote control receiving section
Yes
of the indoor unit.
1. Miswiring may damage indoor electronic control P.C.
*
Yes
No
(Lit or not
Yes
lit)
37
NOTE: Refer to the outdoor unit service manual.
Check the power supply.
Check the wiring.
No
Correct them.
Yes
No
board during the operation.
Be sure to confirm the wiring is correct before the
operation starts.
No
Replace the inverter P.C. board. *2
*2. Be careful of the residual voltage of smoothing
capacitor.
*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.
(Except for outdoor unit of multi system type)