Maintenance And Inspection - Hitachi Koki DH 24PA Handling Instructions Manual

MAINTENANCE AND INSPECTION

1. Inspecting the drill bits
Since use of a dull tool will cause motor
malfunctioning and degraded efficiency, replace the
drill bit with new ones or resharpen them without
delay when abrasion is noted.
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. 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.
4. Inspecting the carbon brushes (Fig. 18)
The motor employs carbon brushes which are
consumable parts. When they become worn to or near
"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 Fig. 18.
In addition, always keep carbon brushes clean and
ensure that they slide freely within the brush holders.
5. Replacing a carbon brush (Fig. 19)
Disassembling
(1) Loosen the three screws on the handle cover, and
remove the handle cover.
(2) Lift out the brush holder together with the carbon
brush, while being very careful not to forcibly pull the
lead wires within the brush holder.
(3) Withdraw the brush terminal, and remove the carbon
brush from the brush holder.
Reassembling
(1) Place a new carbon brush into the brush holder, and
connect the brush terminal to the carbon brush.
(2) Return the brush holder and other parts to their original
positions, as illustrated in Fig. 19.
(3) Place the lead wire in the specified position. Be very
careful not to allow the lead wire to contact the
armature or rotating parts of the motor.
(4) Replace the handle cover, while being careful to ensure
it does not pinch the lead wire, and secure it firmly
with the three screws.
CAUTION
Should the lead wire be pinched by the handle cover
or come in contact with the armature or rotating parts
of the motor, a serious danger of electric shock to the
operator will be created. Excercise extreme caution in
disassembling and reassembling the motor, following
the above procedures exactly.
Do not attempt to disassemble any parts other than
those necessary to effect replacement of the carbon
brush.
NOTE:
Due to HITACHI's continuing program of research and
development, the specifications herein are subject to
change without prior notice.
Information concerning airborne noise and vibration
The measured values were determined according to
EN50144.
The typical A-weighted sound pressure level: 90 dB (A).
The typical sound power level: 103 dB (A).
Wear ear protection.
The typical weighted root mean square acceleration
value: 8.0 m/s 2 .
English
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