Bosch GBH 3-28 E Operating Instructions Manual page 11

EURO • Printed in Germany • BA 1 619 929 474 • GBH 3-28 E • GB • OSW 02/01
GBH 3-28 (474) - Buch Seite 2 Donnerstag, 8. Februar 2001 8:35 08
Intended Use
The machine is intended for hammer drilling in
concrete, brick and stone. It is also suitable for
drilling without impact in wood, metal, ceramic
and plastic.
Changing the Tool
Before any work on the machine itself, pull
the mains plug.
With the SDS-plus tool holder, simpler and easier
tool changing is possible without additional aids.
Grease the shank end of the tool regu-
larly.
Grease chamber
The unit is equipped with a grease chamber,
which automatically lubricates the shank end of
the inserted tool. Should the grease chamber be
empty, it is recommended to have it refilled again
by an after-sales service department. As an alter-
native, the shank end of the tool can also be lu-
bricated manually.
The dust protection cap 1 prevents to a large ex-
tent the entry of drilling dust during operation.
When inserting the tool, take care that the dust
protection cap 1 is not damaged.
A damaged dust protection cap should be
changed immediately. We recommend having
this carried out by an after-sales service.
It is a requirement of the system that the
SDS-plus tool rotates freely, thereby pro-
ducing a radial eccentricity when the ma-
chine is running at no-load speed.
This does not affect the accuracy of the drill
hole, as the bit is automatically centred dur-
ing drilling.
Inserting
A
Clean and grease the shank end of the tool.
Insert the tool in a twisting manner into the tool
holder until it latches itself. Check the latching by
pulling on the tool.
Removing
B
Push back the locking sleeve 2 of the tool holder
and remove the tool.
1 619 929 474 • TMS • 05.02.01
Initial Operation
Do not drill, fasten or cut into blind areas
where electric, gas or water lines may exist.
Use appropriate detectors to determine if
these lines are hidden in the work area or
call the local utility company for assist-
ance.
Contacting electric lines may cause fire or
electric shock. Striking a gas line will probably
result in explosion. Breaking into a water pipe
will cause property damage or may cause an
electric shock.
Check for correct mains voltage: The voltage
of the power source must agree with the voltage
specified on the nameplate of the machine.
Equipment marked with 230 V can also be con-
nected to 220 V.
Switching On and Off
Switching on: Press the On/Off switch 4 and
hold depressed.
Switching off: Release the On/Off switch 4.
For low temperatures,
reaches the full hammer/impact perform-
ance only after a certain time.
This start-up time can be shortened by
striking the drill against the floor one time.
Changing the Speed/
Impact Rate
With the On/Off switch 4, the rotational speed/im-
pact rate can be regulated between low and high
speed/rate. Light pressure on the On/Off switch 4
results in a low rotational speed/impact rate, for
example, for sensitive work such as hole starting.
With increased pressure, the rotational speed/im-
pact rate is increased.
English - 2
the machine