Hitachi RAS-18G5 - Service Operation Circuit; Trouble-Shooting

– 51 –
Is voltage normal (approx. 280 ~
380V) at out put side of the DB201?
Check the circuit board of
control board
YES
NO
Replace faulty P.W.B.
Replace faulty part
*4 Wait for 3 minutes before forced
re-operation by the service switch.
TROUBLE-SHOOTING
No operation at all.
*1
*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.1) Current fuse
2) Varistor
Check whether the appearance is blackish or not.
The resistance must be infi nite. *2
No cooling
Power relay abnormal
YES
Check the continuity between contacts.3) Power switch
(102°C) Continuity across
➝ If there is no continuity,
check the electric parts and replace if abnormal.
4) Thermal fuse for
Terminal board
*2 Before checking the varistor, detach a terminal.
NO
Operates by setting the service
switch to forced cooling?
Return the service switch to "Normal".
Set the remote controller to an
operation status and press the
cooling button.
Is the level LO (approx. 0.5V)
between driver IC501 pin
16
power
relay and 0V?
NO
YES
Compressor does not turn at LO.
Replace Power relay