Dc Voltmeter Or Teste; Smoothing Capacitor; Inrush Protective Resistor - Hitachi RAS-25CNH1 Service Manual

(3) Smoothing capacitor

This smoothes (averages) the voltage rectified by the diode stacks.
‡
A
‡
B
a
VD
DC voltage
(approx. 260-290V during operation)
Fig. 1-3
(4) Smoothing capacitor
This smoothes (averages) the voltage rectified by the diode stacks.
A DC voltage is generated in the same way as in Fig. 1-3.
(5) C805 - C808, C812, C813, L804 (NF coil)
These absorb electrical noise generated during operation of compressor, and also absorb external noise
entering from power line to protect electronic parts.
(6) Surge absorber, varistor 1, 3
These absorbs external power surge.
(7) Inrush protective resistor (R807)
This works to protect from overcurrent
when power is turned on.
R807 Short-circuit → Overcurrent flows in
rush protection ON mode
Open → Overcurrent flows with
power relay turned ON. (damaged each
time power relay is turned ON) Diode stack
and 15A fuse deteriorate.
0
£ £
0
a
0
£ £
0

DC voltmeter or teste

(same as oscilloscop)
0 0 0 0
zzz zzz
0 0
Fig. 1-2
0V
< Reference >
DC voltage can be measured by connecting
both ends of R802 the control P.W.B. using
a tester, etc.
Be careful to avoid an electric shock as a
0V
high voltage is generated. Also take care
not to cause a short-circuit through incorrect
connection of test equipment terminals. The
circuit board could be damaged.
< Reference >
When inrush protective resistor is defective,
diode stack may malfunction. As a result,
DC voltage is not generated and no
operation can be done.
– 63 –
VD
(DC valtage)
V
Both ends of R802
Fig. 1-4