Mitsubishi Electric MSZ-D30NA Service Manual page 25

9-6. TROUBLESHOOTING FLOW
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 any foreign matter that
interferes the rotation of the line
flow fan?
Yes
Remove the foreign matter and
adjust the line flow fan.
Is there 294/325 V DC between
CN211 (+) and
voltage between CN211
(-) rise to the range of 3 to 6 V DC
within 12 seconds after the emer-
gency operation switch is pressed?
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.
OBH501D
Pay enough attention to the high voltage on the fan motor connector CN211.
Turn ON the power supply, wait 5 seconds or more, and then press
the emergency operation switch.
Measure the supply voltage as follows within 12 seconds after the
emergency operation switch is pressed.
No If more than 12 seconds passes by, turn OFF the power supply and
turn ON it again, then measure the voltage. *
1. Measure the voltage between CN211
2. Measure the voltage between CN211
* If 12 seconds or more passes after the emergency operation switch is
pressed, the voltage mentioned above 2 goes 0 V DC although the indoor
electronic control P.C. board is normal
(-), and does the
(+) and
Replace the indoor fan motor.
Yes
No
Is it unchanged holding
0 or 15 V DC?
Replace the indoor fan motor.
(+) and
(+) and
Indoor electronic
control P.C. board
Replace the indoor electronic control P.C. board.
No
(Changed)
Yes
(Unchanged)
25
(-).
(-).
CN211