Hitachi RAC-25YH4, Service Manual, Page: 102 / 121

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WARNING
[A. Control P.W.B.]
Remove four screws securing the control
P.W.B. to the cooling fins, and remove the
control P.W.B. from the cooling fins.
1
[B. Power P.W.B.]
Open the support latches and raise the
power P.W.B. in the direction of the arrow as
shown in Fig. A. 1
Open the support latches and raise
the control P.W.B. in the direction of
the arrow as shown in Fig. A.
2
<Direction of the control P.W.B. removal>
<Direction of the power P.W.B. removal>
Fig. A
Open these support latches to
remove the power P.W.B.
Open these support latches to
remove the control P.W.B.
PRECAUTIONS FOR SERVICING
Be sure that the power switch is turned off or the power cable is disconnected before servicing.
Removing the PWBs.
System Configuration of Outdoor Unit Electrical Parts
The outdoor unit electrical parts consist of two PWBs as shown in the figure.
<Control P.W.B. (M board)>
Contains a rectifier circuit and inverter module, their controlling microcomputer and
microcomputer peripheral control circuits. The board incorporates high and low current sections.
<Power P.W.B. (P board)>
Contains a switching power circuit, noise filter, power factor improvement circuit, etc.
The switching power circuit supplies power to electronic circuits on the control P.W.B. through
CN3.
* When replacing any P.W.B., disconnect all the cables (including ground wires).
RAS_25_35_AW_087-108 2003.12.31, 10:59 AM 100