Hitachi RAF-25FX8 Service Manual page 150

CHECKING THE INDOOR/OUTDOOR UNIT ELECTRICAL PARTS AND REFRIGERATING
Is the indoor unit "timer lamp" blinking?
Run the unit using the following remote controller settings:
In the cooling season, set the temperature to 16˚C in the cooling
mode.
In the heating season, set the temperature to 32˚C in the heating
mode.
Does the operation lamp light or blink?
Is the compressor running?
Running
Open the outdoor unit and observe the self-diagnosis
lamp (LD301). Count how many times the lamp blinks.
Blinks other than 1 time.
Check the refrigerating cycle.
In the event of overload limit cut or OH
thermistor temperature rise, use the
self-diagnosis memory function because
such failure may evade detection due to
ambient temperature variations or other
factors.
No
Yes
Not running
Can the unit be operated using the outdoor unit
service switch?
(See the nameplate on the outdoor unit for operating
instructions.)
No
Check the outdoor
electrical parts.
– 168 –
Yes
Trouble shoot according to the
self-diagnosis lighting mode.
Open the indoor unit and check the voltage
between pins Nos.① and ③ of CN3 on the
No
indoor unit control P.W.B.
Normal: DC35V (32-38V)
Brown
Red
Check if the connecting cable
connected incorrectly? inserted
incompletely? or disconnected?
Blinks 1 time.
Is the voltage correct?
No
Yes
Check the indoor
electrical parts.
Yes