Hitachi RAC-65NH5, Service Manual

Page: 54 / 107

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1. Power Circuit
●
This circuit full-wave rectifies 220-240V AC applied between terminals L and N, and boosts it to a required
voltage with the active module, to create a DC voltage.
The voltage becomes 260-360V when the compressor is operated
(1) Active module
The active filter, consisting of a reactor and
switching element, eliminates higher
harmonic components contained in the
current generated when the compressor is
operated, and improves the power-factor.
(2) Diode stacks
These rectify the 220-240V AC from
terminals L and N to a DC power supply.
< Reference >
●
In case of malfunction or defective connection:
Immediately after the compressor starts, it may stop
due to “abnormally low speed” active error, etc.
The compressor may continue to operate normally,
but the power-factor will decrease, the operation
current will increase, and the overcurrent breaker
of the household power board will probably activate.
●
In case of active module faulty or defective
connection:
Although the compressor continues to operate
normally, the power-factor will decrease, the
operation current will increase, and the overcurrent
breaker of the household power board will probably
activate.
< Reference >
●
If diode stack 1 is faulty, the compressor may stop
due to “lp”, “anbormally low speed”, etc. immediately
after it starts, or it may not operate at all because
no DC voltage is generated between the positive
e
and negative d terminals.
If diode stack 1 is faulty, be aware that the 25A
fuse might also have blown.
●
If diode stack 2 is faulty, DC voltage may not be
generated and the compressor may not operate at
all. Also, be aware that the 3A fuse might have
blown.
L
25A FUSE
SURGE-
ABSORBER
VARIST
OR1
VARIST
OR3
CT1
C009
L001
C001
C004
C005
C006 R007
L002
JW6
R008
ICP RELAY
TB2
TB8
TB7 TB6
TB10
TB11
TB12
U
V
W
N1
L1 L2
3A FUSE
R002
C008
C007
C012
C013
C014
C015
DIODE
STACK 2 (RC2)
DIODE
STACK 1
(D25VB60)
VARIST
OR2
C011
PO
WER CIRCUIT
R010
R011
C002
C003
R001
0V
0V
NF COIL1
COIL POWER RELAY
TERMINAL
BOARD
N
REACTOR
C010
SPM2
P1
Vd b a
Fig. 1-1