Description Of Main Circuit Operation - Hitachi RAM-60QH4 Manuel De Service

DESCRIPTION OF MAIN CIRCUIT OPERATION

MODEL RAM-60QH4
1. Power circuit
POWER P.W.B(1/2)
25A-FUSE
BLK
L
VARISTOR 1
SURGE
ABSORBER
R001
WHT
N
L007
C71
GRN1
0V
C103
0V
GRN2
JW5
GRN3
SWITCHING POWER P.W.B
• This circuit full-wave rectifies 230 V 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 300-330V when the compressor is operated.
(1) System power module (SPM)
(Current ACT module, smoothing capacitors and power
module are combined into one unit)
① Active module
The active fiter, consisting of a reactor and switching lement,
eliminates higher harmonic components contained in the
current generated when the compressor is operated, and
improves the power-factor.
Smoothing capacitor smoothes voltage, which has been
rectified by diode stack and boosted at ACT section.
② Power module section
Refer to Item 3 System Power Module Circuit.
(2) Diode stacks 1, 2
These rectify the 230 V AC from terminals L and N to a DC
power supply.
COIL
NF COIL
R009
L006
DIODE STACK
＋
R005
＋
POWER RELAY
YEL
＋
TB8
GRY
R002 R003
ICP RELAY
JW3
−
RED TB2
BLU
Fig.1-1
<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 contact:
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 bridge 1 is faulty, the compressor may stop due
to "lp", "abnormally low speed", etc.
immediately after it starts, or it may not operate at all
because no DC voltage is generated between the
positive + and negative - terminals.
If diode bridge 1 is faulty, be aware that the 25A fuse
might also have blown.
• If diode bridge 2 is faulty, DC voltage may be not
generated and the compressor may not operate at all.
Also, be aware that the 3A fuse might have blown.
– 80 –
REACTOR
YEL YEL
SPM2
L1 L2
TB7 TB6
TB11
TB11
TB11