Bosch GBH 4-32 DFR Professional - Manual (Page 16)

16 | English
1 609 92A 044 | (10.1.13) Bosch Power Tools
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 5.
Note: Change the operating mode only when the machine is
switched off! Otherwise, the machine can be damaged.
– Turn the mode selector switch 5 to the requested position.
Reversing the rotational direction
 Actuate the rotational direction switch 8 only when the
machine is at a standstill.
The rotational direction switch 8 is used to reverse the rota-
tional direction of the machine.
Right rotation: Turn the rotational direction switch 8 to the
stop in the position
.
Left rotation: Turn the rotational direction switch 8 to the
stop in the position
.
Set the direction of rotation for hammer drilling, drilling and
chiselling always to right rotation.
Switching On and Off
– To start the machine, press the On/Off switch 7 and keep
it pressed.
– To switch off the machine, release the On/Off switch 7.
For low temperatures, the power tool reaches the full ham-
mer/impact capacity only after a certain time.
To save energy, only switch the power tool on when using it.
Setting the Speed/Impact Rate
The speed/impact rate of the switched on power tool can be
variably adjusted, depending on how far the On/Off switch 7
is pressed.
Light pressure on the On/Off switch 7 results in low speed/im-
pact rate. Further pressure on the switch increases the
speed/impact rate.
Safety Clutch
 If the tool insert becomes caught or jammed, the drive
to the drill spindle is interrupted. Because of the forces
that occur, always hold the power tool firmly with both
hands and provide for a secure stance.
 If the power tool jams, switch the machine off and loos-
en the tool insert. When switching the machine on with
the drilling tool jammed, high reaction torques can oc-
cur.
Changing the Chiselling Position (Vario-Lock)
The chisel can be locked in 13 positions. In this manner, the
optimum working position can be set for each application.
– Insert the chisel into the tool holder.
– Turn the mode selector switch 5 to the “Vario-Lock” posi-
tion (see “Setting the operating mode”, page 16).
– Turn the tool holder to the desired chiselling position.
– Turn the mode selector switch 5 to the “chiselling” posi-
tion. The tool holder is now locked.
– For chiselling, set the rotation direction to right rotation.
Working Advice
 Before any work on the machine itself, pull the mains
plug.
Vibration Damper
The integrated vibration damper reduces occurring vibra-
tions.
Maintenance and Service
Maintenance and Cleaning
 Before any work on the machine itself, pull the mains
plug.
 For safe and proper working, always keep the machine
and ventilation slots clean.
 A damaged dust protection cap should be changed im-
mediately. We recommend having this carried out by
an after-sales service.
If the replacement of the supply cord is necessary, this has to
be done by Bosch or an authorized Bosch service agent in or-
der to avoid a safety hazard.
If the machine should fail despite the care taken in manufac-
turing and testing procedures, repair should be carried out by
an after-sales service centre for Bosch power tools.
Position for drilling without im-
pact in wood, metal, ceramic and
plastic as well as for screwdriving
Position for hammer drilling in
concrete or stone
When the drilling tool does not
immediately rotate upon switch-
ing on, allow the machine to run
slowly until the drilling tool ro-
tates.
Vario-Lock position for adjust-
ment of the chiselling position
Position for chiselling
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