Maintenance And Inspection - Hitachi Koki X 303 Handling Instructions Manual

4. Switch operation
Switch ON: To switch on, slide the lock lever in the
direction of A and press the paddle
lever in the direction of B as shown
in Fig. 3-a.
Furthermore, slide the lock lever in the
direction of C shown in Fig. 3-b while
pressing the paddle lever to lock and
enable continuous operation.
Switch OFF: To release the locking mode, press the
paddle lever in the direction of B shown
in Fig. 3-a, and release the paddle lever
to switch off.
5. Precautions immediately after finishing operation
The wheel continues to rotate after the tool is
switched off.
After switching off the machine, do not put it down
until the depressed center wheel has come to a
complete stop. Apart from avoiding serious
accidents, this precaution will reduce the amount
of dust and swarf sucked into the machine.
CAUTIONS
Check that the work piece is properly supported.
Ensure that ventilation openings are kept clear when
working in dusty conditions.
If it should become necessary to clear dust, first
disconnect the tool from the mains supply (use non-
metallic objects) and avoid damaging internal parts.
Ensure that sparks resulting from use do not create
a hazard e.g. do not hit persons, or ignite flammable
substances.
Always use protective safety glasses and hearing
protectors, use other personal protective equipment
such as gloves, apron and helmet when necessary.
Always use eye and ear protection.
Other personal protective equipment such as dust
mask, gloves, helmet and apron should be worn
when necessary.
If in doubt, wear the protective equipment.
When the machine is not use, the power source
should be disconnected.
ASSEMBLING AND DISASSEMBLING THE
DEPRESSED CENTER WHEEL (Fig. 1)
CAUTION
Be sure to switch OFF and disconnect the attachment
plug from the receptacle to avoid a serious accident.
1. Assembling (Fig. 1)
(1) Turn the disc grinder upsidedown so that the spindle
is facing upward.
(2) Align the across flats of the wheel washer with the
notched part of the spindle, then attach them.
(3) Fit the protuberance of the depressed center wheel
onto the wheel washer.
(4) Screw the wheel nut onto the spindle.
(5) While pushing the push button with one hand, lock
the spindle by turning the depressed center wheel
slowly with the other hand.
Tighten the wheel nut by using the supplied wrench
as shown in Fig. 1.
2. Disassembling
Follow the above procedures in reverse.
CAUTIONS
Comfirm that the depressed center wheel is mounted
firmly.
Confirm that the push button is disengaged by
pushing push button two or three times before
switching the power tool on.

MAINTENANCE AND INSPECTION

1. Inspecting the depressed center wheel
Ensure that the depressed center wheel is free of
cracks and surface defects.
2. Inspecting the mounting screws
Regularly inspect all mounting screws and ensure
that they are properly tightened. Should any of the
screws be loose, retighten them immediately. Failure
to do so could result in serious hazard.
3. Inspecting the carbon brushes (Fig. 4)
The Motor employs carbon brushes which are
consumable parts. When they become worn to or
near the "wear limit", it could result in motor
trouble. When an auto-stop carbon brush is
equipped, the motor will stop automatically. At that
time, replace both carbon brushes with new ones
which have the same carbon brush Numbers shown
in the figure. In addition, always keep carbon brushes
clean and ensure that they slide freely within the
brush holders.
4. Replacing carbon brushes (Fig. 5)
〈 Disassembly 〉
(1) Loosen the D4 tapping screw retaining the tail cover
and remove the tail cover.
(2) Use the auxiliary hexagonal wrench or small
screwdriver to pull up the edge of the spring that
is holding down the carbon brush. Remove the
edge of the spring toward the outside of the brush
holder.
(3) Remove the end of the pig-tail on the carbon brush
from the terminal section of brush holder and then
remove the carbon brush form the brush holder.
〈 Assembly 〉
(1) Insert the end of the pig-tail of the carbon brush
in the terminal section of brush holder.
(2) Insert the carbon brush in the brush holder.
(3) Use the auxiliary hexagonal wrench or small
screwdriver to return the edge of the spring to the
head of the carbon brush.
(4) Mount the tail cover and tighten the D4 tapping
screw.
5. Maintenance of the motor
The motor unit winding is the very "heart" of the
power tool. Exercise due care to ensure the winding
does not become damaged and/or wet with oil or
water.
6. Service parts list
A: Item No.
B: Code No.
C: No. Used
D: Remarks
CAUTION
Repair, modification and inspection of Hitachi Power
Tools must be carried out by an Hitachi Authorized
Service Center.
This Parts List will be helpful if presented with the
tool to the Hitachi Authorized Service Center when
requesting repair or other maintenance.
In the operation and maintenance of power tools,
the safety regulations and standards prescribed in
each country must be observed.
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