Bosch Professional GSB 20-2 Original Instructions Manual page 15

Place the power tool on a firm surface, e.g. a work bench.
Hold the power tool in place and loosen the keyless chuck
(1) by turning the hex key (15) in the rotational direction ➊.
A tightly seated keyless chuck is loosened with a light blow
on the long shaft of the hex key (15). Remove the hex key
from the keyless chuck and completely unscrew the keyless
chuck from the power tool.
Fitting the Drill Chuck (see figure F)
To fit the keyless chuck/keyed chuck, perform the same
steps in reverse order.
The drill chuck must be tightened using a tight-
ening torque of approx. 50–55 Nm.
After successfully fitting the drill chuck, remove the
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steel pin from the hole again.
Dust/Chip Extraction
Dust 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 dust can cause allergic
reactions and/or lead to respiratory infections of the user or
bystanders.
Certain dust, such as oak or beech dust, is considered carci-
nogenic, especially in connection with wood-treatment ad-
ditives (chromate, wood preservative). Materials containing
asbestos may only be worked by specialists.
– 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 ma-
terials to be worked.
Avoid dust accumulation at the workplace. Dust can
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easily ignite.
Operation
Starting Operation
Pay attention to the mains voltage. The voltage of the
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power source must match the voltage specified on the
rating plate of the power tool. Power tools marked
with 230 V can also be operated with 220 V.
Products that are only sold in AUS and NZ: Use a resid-
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ual current device (RCD) with a nominal residual current
of 30 mA or less.
Setting the rotational direction (see figure G)
Only operate the rotational direction switch (3) when
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the power tool is not in use.
The rotational direction switch (3) is used to change the ro-
tational direction of the power tool. However, this is not pos-
sible while the on/off switch (6) is being pressed.
Clockwise rotation: To drill and drive in screws, slide the
rotational direction switch (3) downwards on the left-hand
side and upwards on the right-hand side at the same time.
Anti-clockwise rotation: To loosen and unscrew screws and
nuts, slide the rotational direction switch (3) upwards on the
Bosch Power Tools
left-hand side and downwards on the right-hand side at the
same time.
Setting the Operating Mode
Drilling and screwdriving
Set the selector switch (2) to the "drilling"
symbol.
Impact drilling
Set the selector switch (2) to the "impact
drilling" symbol.
The selector switch (2) clicks into place and
can also be actuated when the motor is running.
Mechanical Gear Selection
You can press the gear selector switch (7) with the
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power tool running at a low speed. You should not do
this at full load or maximum torque, or when the tool is
not in use, however.
You can preselect two speed ranges with the gear selector
(7).
First gear:
Low speed range; for working with a large
drilling diameter or for screwdriving.
Second gear:
High speed range; for working with a small
drilling diameter.
If the gear selector (7) cannot be swivelled all the way to the
stop, turn the drive spindle slightly with the drill.
Switching on/off
To start the power tool, press and hold the on/off switch
(6).
Press the lock-on button (4) to lock the on/off switch (6) in
this position.
To switch off the power tool, release the on/off switch (6);
or, if the switch is locked with the lock-on button (4), briefly
press the on/off switch (6) and then release it.
Emergency switch-off (KickBack Control)
The emergency switch-off function (Kick-
Back Control) gives the user greater control
over the power tool and offers them better
protection than power tools that do not
have KickBack Control. The power tool will switch off if it
suddenly and unforeseeably rotates around the drilling
axis.
Rapid shut-off is indicated by the LED on the power tool
flashing.
To switch the tool back on, release the on/off switch and
then press it again.
If the KickBack Control function is defective, it will no
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longer be possible to switch the power tool on. Have
the power tool serviced by a qualified repair person
using only original replacement parts.
English | 15
1 609 92A 55U | (18.11.2019)