Hitachi RAS-10G5 Service Manual page 54

TROUBLE-SHOOTING
No cooling
Operates by setting the service
switch to forced cooling?
YES
Return the service switch to "Normal".
Set the remote controller to an
operation status and press the ON/
OFF button.
Is the level LO (approx. 0.5V)
between driver IC501 pin
relay and 0V?
NO
Is voltage normal between blue wire
and red wire of Indoor DC Fan Motor.
NO
Is voltage normal (approx. 280 ~
380V) at out put side of the DB1?
NO
Replace control P.W.B.
No operation at all.
*1
NO
1) Current fuse
2) Varistor
3) Power switch
10 power
Power relay abnormal
YES
Compressor does not turn at LO.
Indoor fan motor or
ICP1 or Q109 abnormal
YES
*3 Refer to below table.
Check the circuit board
YES
*4 Wait for 3 minutes before forced
re-operation by the service switch.
*3
Fan Speed
SLEEP MODE
*1 Before using the service switch, disengage
and engage the plug. Do not operate the
remote controller.
Check the following parts and replace if faulty
Remove and check the continuity across.
Check whether the appearance is blackish or not.
The resistance must be infi nite. *2
Check the continuity between contacts.
*2 Before checking the varistor, detach a terminal.
of control board
CN5 BLUE-RED (V)
RAS-10G5
RAC-10G5
Cool
HI 23.0
19.0
MED
15.6
LO
11.9
– 58 –
Replace Power relay
Replace faulty part
RAS-14G5
RAC-14G5
Cool
30.3
25.6
20.0
13.5