Hitachi RAS-25WX8 Manuel De Maintenance page 158

PRECAUTIONS FOR SERVICING
Be sure that the power switch is turned off or the power cable is disconnected before servicing.
Removing the P.W.B. .
System Configuration of Outdoor Unit Electrical Parts
The outdoor unit electrical parts consist of two P.W.B. as shown in the figure.
<Main 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 main P.W.B. through
CN3.
* When replacing any P.W.B., disconnect all the cables (including ground wires).
[A. Main P.W.B.]
Remove four screws securing the main
1
P.W.B. to the cooling fins, and remove the
main P.W.B. from the cooling fins.
[B. Power P.W.B.]
1 Open the support latches and raise the
power P.W.B. in the direction of the arrow as
shown in Fig. A.
<Direction of the power P.W.B. removal>
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WARNING
Open the support latches and raise
2
the main P.W.B. in the direction of
the arrow as shown in Fig. A.
<Direction of the main P.W.B. removal>
Open these support latches to
remove the main P.W.B.
– 157 –
Open these support latches to
remove the power P.W.B.
Fig. A