Hitachi RAS-50WX8 Service Manual page 159

POWER CIRCUIT
PHENOMENON 1 <ROTATION SPEED DOES NOT INCREASE>
Is the DC voltage at least 350V?
Is the OVL lamp lit?
If the lamp is lit, it does not
indicate fault, but the unit is
overload status.
Overvoltage defect : ACT module faulty
(15 times blinking)
HOW TO CHECK POWER MODULE
Checking power module using tester
Set tester to resistance range (×100)
If indicator does not swing in the following conductivity check, the power module is normal.
(In case of digital tester, since built-in battery is set in reverse direction, + and - terminals are reversed.)
CAUTION
!
If inner circuit of power module is disconnected (open), the indicator of tester will not swing and this may
assumed as normal. In this case, if indicator swings when + and - terminals are connected in reverse of
diagram below, it is normal. Furthemore, compare how indicator swings at U, V and W phases. If indicator
swings the same way at each point, it is normal.
Yes
– 200 –
Recheck cord, etc. of the ACT
module. If they are disconnected,
connect them securely.
If abnormality conitinues,
replace the ACT module.