Troubleshooting Flow; Check Of Indoor Fan Motor - Mitsubishi Electric MLZ-KP09NA Service Manual

9-6. TROUBLESHOOTING FLOW

When the left lamp of OPERATION INDICATOR lamp blinks 3 times and the right lamp of OPERATION INDICATOR
lamp is not lighted.
Indoor fan does not operate.
A

Check of indoor fan motor

The indoor fan motor error has occurred, and the indoor fan does not operate.
Turn OFF the power supply.
Is there anything that interferes the
rotation of the line flow fan?
Yes
Remove the object and
adjust the line flow fan.
Is there 294/325 V DC
between CN211
and (–)?
No
Replace the indoor electronic control P.C. board.
The indoor fan motor error has occurred, and the indoor fan repeats "12-second ON and 30-second OFF" 3 times, and then stops.
Measure the voltage between CN211
(+) and (-) while the fan
motor is rotating.
Indoor electronic
control P.C. Board
C111
CN211
OBH802A
Pay attention to the high voltage on the fan motor connector CN211.
Turn ON the power supply, wait 5 seconds or more, and then press
EMERGENCY OPERATION switch.
Measure the supply voltage as follows within 12 seconds
after EMERGENCY OPERATION switch is pressed.
If more than 12 seconds passes by, turn OFF the power supply and
No
turn ON it again, then measure the voltage.
1) Measure the voltage between CN211
2) Measure the voltage between CN211
If more than 12 seconds pass after EMERGENCY OPERATION switch
is pressed, the voltage mentioned in above 2) goes 0 V DC although the
indoor electronic control P.C. board is normal.
Does the voltage between CN211
(+) and (–) on the indoor electronic
control P.C. board rise to the range of
(+)
3 to 6 V DC within 12 seconds after
Yes
EMERGENCY OPERATION switch
is pressed?
Is 0 V DC or 15 V DC
held unchanged?
Replace the indoor fan motor.
sandium.com
(+) and
(+) and
Replace the indoor fan motor.
Yes
No
Replace the indoor electronic control P.C. board.
No
(Changed)
Yes
(Unchanged)
28
(-).
(-).