23
C Check of indoor P.C. board and indoor fan motor
Turn OFF the power supply.
Remove indoor fan motor connector CN211
and vane motor connector CN151 from the
indoor electronic control P.C. board and turn
ON the power supply.
Does the unit operate with the remote
controller?
Does OPERATION INDICATOR lamp light
up by pressing EMERGENCY OPERATION
switch?
Yes
No
Measure the resistance of indoor fan
motor.
Refer to 10-5.
Short circuit:
Replace the indoor fan motor.
Turn OFF the power supply.
Check both “parts side” and “pattern
side” of the indoor power P.C. board
visually.
Replace the varistor (NR11)
and fuse (F11). 1
Are the varistor (NR11)
burnt and the fuse (F11)
blown?
No
No
Yes
Yes
Be sure to check both the fuse
and the varistor in any case.
Is the fuse (F11) blown
only?
Measure the resistance between
CN211 (+) and (-) of indoor fan
motor connector. 2, 3
Yes
Is the resistance 1MΩ or more?
Replace the fuse (F11) and the
indoor fan motor. 3
No
Replace the fuse (F11). 1
Measure the resistance of resistor (R111)
on the indoor power P.C. board.
No
Replace the indoor electronic
control P.C. board and the indoor
fan motor.
Replace the indoor electronic control P.C. board.
Measure the resistance of the vane
motor coil.
Refer to 10-5.
Short circuit:
Replace the vane motor and the indoor
electronic control P.C. board.
1. Please replace the fuse after removing the
indoor power P.C. board from the electrical
box.
2. The fan motor connector's lead wire is red,
whereas is black.
3. Connect "+" of the tester to fan motor
connector's
lead wire, and “-” to
lead wire,
otherwise the resistance cannot be measured
properly.
Is the resistance of resistor (R111)
approximately 4 Ω ?
Yes
Indoor electronic
control P.C. board
GND
12 VDC
5 VDC
FUSE (F11)
Varistor (NR11)
OBH849A
