MITSUBISHI ELECTRIC MSZ-FD25VAS - Manual (Page 28)

28
10-6. TROUBLESHOOTING FLOW
Check of indoor fan motor A
POWER lamp flashes 3-time.
Indoor fan does not operate.
w If more than 12 seconds passes after EMERGENCY OPERATION switch
is pressed, the voltage mentioned above 2 goes 0 VDC although the
indoor electric control P.C. board is normal.
Indoor electronic
control P.C. board
Pay careful attention to the high voltage on
the fan motor connector CN211.
Yes
No
No
No
(Changed)
Yes
(Unchanged)
Is there any foreign matter that
interferes the rotation of the line
flow fan?
Turn OFF the power supply.
Remove the foreign matter and
adjust the line flow fan.
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
turn ON it again, then measure the voltage.
w
1.Measure the voltage between CN211 1 (+) and 3 (-).
2.Measure the voltage between CN211 5 (+) and 3 (-).
Is there 325 VDC between
CN211
1 (+) and 3 (-), and does
the voltage between CN211 5 (+)
and 3 (-) rise to the range of 3 to 6
VDC within 12 seconds after
EMERGENCY OPERATION switch
is pressed?
Yes
Replace the indoor fan motor.
CN211
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
6 (+) and 3 (-) while the fan motor is
rotating.
Is it unchanged holding
0 or 15 VDC?
Replace the indoor fan motor.
Replace the indoor electronic control P.C. board.
The indoor fan motor error has occurred, and the indoor fan doesn't operate.
OBH488-1.qxp 07.8.9 11:47 AM Page 28