Bosch GBH Professional 500 Original Instructions Manual page 13

OBJ_BUCH-273-003.book Page 13 Thursday, January 10, 2013 2:32 PM
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 3.
Note: Change the operating mode only when the machine is
switched off! Otherwise, the machine can be damaged.
– Turn the mode selector switch 3 to the requested position.
Position for hammer drilling in concrete or
stone
When the drilling tool does not immediately
rotate upon switching on, allow the machine
to run slowly until the drilling tool rotates.
Vario-Lock position for adjustment of the
chiselling position
Position for chiselling
Switching On and Off
– To start the machine, press the On/Off switch 4 and keep
it pressed.
– To switch off the machine, release the On/Off switch 4.
For low temperatures, the machine reaches the full ham-
mer/impact capacity only after a certain time.
This start-up time can be shortened by striking the inserted
tool insert against the floor one time.
To save energy, only switch the power tool on when using it.
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 loosen
the tool insert. When switching the machine on with the
drilling tool jammed, high reaction torques can occur.
Changing the Chiselling Position (Vario-Lock)
The chisel can be locked in 12 positions. In this manner, the
optimum working position can be set for each application.
– Insert the chisel into the tool holder.
Bosch Power Tools
– Turn the mode selector switch 3 to the "Vario-Lock" posi-
tion (see "Setting the operating mode", page 13).
– Turn the tool holder to the desired chiselling position.
– Turn the mode selector switch 3 to the "chiselling" posi-
tion. The tool holder is now locked.
 The mode selector switch 3 must always be locked in
the "Chiselling" position when chiselling.
Working Advice
 Before any work on the machine itself, pull the mains
plug.
Sharpening Chisels (see figure C)
Good results are only achieved with sharp chisels; therefore,
sharpen the chiselling tools in good time. This ensures a long
service life of the tools and good working performance.
– Re-sharpening
Sharpen chiselling tools using grinding wheels (e. g. ce-
ramic bonded corundum wheel) with a steady supply of
water. Reference values are shown in the figure. Take care
that no annealing coloration appears on the cutting edges;
this impairs the hardness of the chiselling tools.
– For forging, heat the chisel to between 850 and 1050 °C
(bright red to yellow).
– For hardening, heat the chisel to approx. 900 °C and
quench in oil. Then anneal in an oven for approx. one hour
at 320 °C (annealing colour = light blue).
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.
Lubrication
The power tool is oil-lubricated. An oil change is required only
within the scope of maintenance or repair through an author-
ised after-sales service agent for Bosch power tools. In this, it
is absolutely required to use the specified Bosch oil.
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.
In all correspondence and spare parts order, please always in-
clude the 10-digit article number given on the type plate of
the machine.
English | 13
1 609 92A 045 | (10.1.13)