Starting Operation - Bosch 3-28 DRE Original Instructions Manual

OBJ_BUCH-873-008.book Page 10 Wednesday, November 25, 2015 11:10 AM
10 | English
Removing Drilling Tools without SDS-plus
(GBH 3-28 DFR) (see figure I)
– Firmly hold the retaining ring 21 of the quick change
chuck. Open the tool holder by turning the front sleeve 20
in the direction of the arrow until the tool can be removed.
Dust Extraction with the Dust Extraction Attach-
ment (Accessory)
 Dusts from materials such as lead-containing coatings,
some wood types, minerals and metal can be harmful to
one's health. Touching or breathing-in the dusts can cause
allergic reactions and/or lead to respiratory infections of
the user or bystanders.
Certain dusts, such as oak or beech dust, are considered
as carcinogenic, especially in connection with wood-treat-
ment additives (chromate, wood preservative). Materials
containing asbestos may only be worked by specialists.
– As far as possible, use a dust extraction system suita-
ble for the material.
– Provide for good ventilation of the working place.
– It is recommended to wear a P2 filter-class respirator.
Observe the relevant regulations in your country for the
materials to be worked.
 Prevent dust accumulation at the workplace. Dusts can
easily ignite.
Mounting the Dust Extraction Attachment (see figure J)
For dust extraction, the dust extraction attachment (accesso-
ry) is required. When drilling, the dust extraction attachment
retracts so that the attachment head is always close to the
surface at the drill hole.
– Press the button for depth stop adjustment 10 and remove
the depth stop 11. Press button 10 again and insert the
dust extraction attachment into the auxiliary handle 12
from the front.
– Connect an extraction hose (diameter 19 mm, accessory)
to the extraction sleeve 22 of the dust extraction attach-
ment.
The vacuum cleaner must be suitable for the material being
worked.
– When vacuuming dry dust that is especially detrimental to
health or carcinogenic, use a special vacuum cleaner.
Adjusting the Drilling Depth on the Dust Extraction
Attachment (see figure K)
The required drilling depth X can also be adjusted when the
dust extraction attachment is mounted.
– Insert the SDS-plus drilling tool to the stop into the SDS-
plus tool holder 3. Otherwise, the movability of the SDS-
plus drilling tool can lead to incorrect adjustment of the
drilling depth.
– Loosen the wing bolt 26 on the dust extraction attachment.
– Without switching the power tool on, apply it firmly to the
drilling location. The SDS-plus drilling tool must face
against the surface.
– Position the the guide pipe 27 of the dust extraction at-
tachment in its holding fixture in such a manner that the
head of the dust extraction attachment faces against the
surface to be drilled. Do not slide the guide pipe 27 further
1 609 92A 1VK | (25.11.15)
over the telescopic pipe 25 of the dust extraction attach-
ment than required, so that as much as possible of the
scale 25 on the telescopic pipe remains visible.
– Retighten the wing bolt 26 again. Loosen the clamping screw
23 on the depth stop of the dust extraction attachment.
– Move the depth stop 24 on the telescopic pipe 25 in such
a manner that the clearance X shown in the figure corre-
sponds with the required drilling depth.
– Tighten the clamping screw 23 in this position.
Operation

Starting Operation

 Observe correct mains voltage! The voltage of the pow-
er source must agree with the voltage specified on the
nameplate of the machine. Power tools marked with
230 V can also be operated with 220 V.
Setting the operating mode
The operating mode of the power tool is selected with the
mode selector switch 9.
Note: Change the operating mode only when the machine is
switched off! Otherwise, the machine can be damaged.
– To change the operating mode, push the release button 8
and turn the mode selector switch 9 to the requested posi-
tion until it can be heard to latch.
Position for hammer drilling in concrete or
stone
Position for drilling without impact in wood,
metal, ceramic and plastic as well as for
screwdriving
Vario-Lock position for adjustment of the
chiselling position
The mode selector switch 9 does not latch in
this position.
Position for chiselling
Reversing the rotational direction
The rotational direction switch 13 is used to reverse the rota-
tional direction of the machine.
 Actuate the rotational direction switch 13 only when
the machine is at a standstill.
Right rotation: Turn the rotational direction switch 13 to
the stop in position .
Left rotation: Turn the rotational direction switch 13 to
the stop in position .
Bosch Power Tools