Practical Grinder Application; Maintenance And Inspection - Hitachi G 10SR3 Handling Instructions Manual

9. RCD
The use of a residual current device with a rated
residual current of 30mA or less at all times is
recommended.

PRACTICAL GRINDER APPLICATION

1. Pressure
To prolong the life of the machine and ensure a
first class finish, it is important that the machine
should not be overloaded by applying too much
pressure. In most applications, the weight of the
machine alone is sufficient for effective grinding.
Too much pressure will result in reduced rotational
speed, inferior surface finish, and overloading which
could reduce the life of the machine.
2. Grinding angle
Do not apply the entire surface of the depressed
center wheel to the material to be ground. As
shown in Fig. 1, the machine should be held at an
angle of 15° – 30° so that the external edge of the
depressed center wheel contacts the material at an
optimum angle.
3. To prevent a new depressed center wheel from
digging into the workpiece, initial grinding should
be performed by drawing the grinder across the
workpiece toward the operator (Fig. 1 direction B).
Once the leading edge of the depressed center
wheel is properly abraded, grinding may be
conducted in either direction.
4. 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 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. 2)
CAUTION Be sure to switch OFF and disconnect the
attachment plug from the receptacle to avoid
a serious accident.
1. Assembling (Fig. 2)
(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. 2.
2. Disassembling
Follow the above procedures in reverse.
CAUTIONS
Confirm 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
For your continued safety and electrical shock
protection, carbon brush inspection and replacement
on this tool should ONLY be performed by a HITACHI
AUTHORIZED SERVICE CENTER.
4. Replacing supply cord
If the replacement of the supply cord is necessary,
it has to be done by Hitachi Authorized Service
Center to avoid a safety hazard.
5. Maintenance of the motor
WARNING
Always wear protective goggles and dust respirators
when blowing air from the tail cover air hole with
the use of an air gun, etc.
Failure to observe this may result in ejected dust
being inhaled or entering your eyes.
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.
NOTE
When work has been finished, blow air containing
no moisture from the tail cover air hole with the
use of an air gun, etc., while running the motor
without any load applied. This is effective in
removing any dirt and dust that has accumulated.
Dirt and dust collecting inside the motor may result
in malfunctions.
6. Service parts list
A: Item No.
B: Code No.
C: No. Used
D: Remarks
English
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