Check Of Indoor Electronic Control P.c. Board; Check Of Outdoor Unit - Mitsubishi Electric MSH-18RV Service Manual

Check of indoor electronic control P.C. board

C
The unit doesn't operate with the remote controller. Also, the OPERATION INDICATOR lamp doesn't light up by press-
ing the EMERGENCY OPERATION switch.
Check the both "parts side" and "pattern
side" of indoor electronic control P.C.
board visually.
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 the OPERATION INDICATOR lamp light up
by pressing the EMERGENCY OPERATION switch?
Yes
Replace the vane
Turn OFF the
motor.
power supply.
Is winding
resistance of
vane motor 0 "?
Be sure to check both resistance.
Is winding
resistance of
fan motor 0 "?
Replace the fan
motor.

Check of outdoor unit

D
Compressor and or outdoor fan motor doesn't operate.
MSH-18RV
Start
Press the EMERGENCY OPERATION switch.
3-minute time delay works.
Test run operation operates for 30 minutes.
Check the voltage to the terminal block of outdoor
unit. Is there 220-240V AC to the terminal block
between - ?
2 N
No
Check the voltage to the terminal block of indoor unit.
Is there 220-240V AC to the terminal block between
- ?
2 N
No
Replace the indoor elec-
tronic control P.C. board.
MSH-18/24RV
No
Turn OFF the
power supply.
Yes
No
Is fuse(F11) blown?
Be sure to check both fuse
and varistor in any case.
Is varistor(NR11) burnt?
No
Yes
Replace the varistor.
Yes
Yes
1
1
2
3
F12
CN201
L
N
Terminal
block
Replace the fuse.
Yes
No
(MSH-
18/24RV)
No
Yes
Check the outdoor DEICER P.C.board at first, then check
the outdoor fan motor and the compressor.
Check the continuity of indoor and outdoor unit connection.
60
Varistor (NR11)
MSH-30RV
Fuse (F11)
Indoor electronic
control P.C. board
(MSH-30RV)
Replace the indoor
electronic control
P.C. board.
Measure the
resistance between
1
CN201 on the
Is resistance approx. 0"?
indoor electronic
control P.C. board
N
and on the terminal
block with the tester.
Replace the fuse (F12).
Yes
No(∞)