Bosch GBH Professional 2-28 Manual Original página 18

18 | English
Operation
Products that are only sold in AUS and NZ: Use a resid-
u
ual current device (RCD) with a nominal residual current
of 30 mA or less.
Start-up
Pay attention to the mains voltage. The voltage of the
u
power source must match the voltage specified on the
rating plate of the power tool.
Setting the Operating Mode
The operating mode of the power tool is selected using the
impact/mode selector switch (11).
– To change the operating mode, press the release
button (10) and turn the impact/mode selector
switch (11) until it clicks into the required position.
Note: Only change the operating mode when the power tool
is switched off. Otherwise, the power tool may become dam-
aged.
Position for hammer drilling into concrete or
stone
Position for drilling without impact in wood,
metal, ceramic and plastic and for screwdriv-
ing
Vario-Lock position for adjusting the chisel po-
sition
The impact/mode selector switch (11) will not
engage in this position.
Position for chiselling
Setting the Rotational Direction
The rotational direction switch (7) is used to change the ro-
tational direction of the power tool. However, this is not pos-
sible while the on/off switch (9) is being pressed.
Only operate the rotational direction switch (7) when
u
the power tool is not in use.
Always set the rotational direction to clockwise rotation for
hammer drilling, drilling and chiselling.
– Rotate clockwise: Turn the rotational direction
switch (7) on both sides until it stops in the
– Rotate anticlockwise: Turn the rotational direction
switch (7) on both sides until it stops in the
Switching On/Off
– To switch on the power tool, press the on/off switch (9).
– To lock the on/off switch (9), press and hold it while also
pushing the lock-on button (8).
– To switch off the power tool, release the on/off switch
(9). If the on/off switch (9) is locked, press the switch
first and then release it.
1 609 92A 9A8 | (15.04.2024)
Adjusting the Speed/Impact Rate
You can adjust the speed/impact rate of the power tool when
it is on by pressing in the on/off switch (9) to varying ex-
tents.
Applying light pressure to the on/off switch (9) results in a
low rotational speed/impact rate. Applying increasing pres-
sure to the switch increases the speed/impact rate.
Changing the chiselling position (Vario-Lock)
You can lock the chisel in 36 different positions, so you can
select the optimum working position for each task.
– Insert the chisel into the tool holder.
– Turn the impact/mode selector switch (11) to the "Vario-
Lock" position.
– Turn the application tool to the required chisel position.
– Turn the impact/mode selector switch (11) to the "chis-
elling" position. With this, the tool holder is locked.
– Set the rotational direction for chiselling to clockwise.
Practical Advice
Setting the drilling depth (see figure J)
You can use the depth stop (14) to set the required drilling
depth X.
– Press the button for depth stop adjustment (12) and in-
sert the depth stop into the auxiliary handle (13).
The fluting on the depth stop (14) must face downwards.
– Push the SDS plus application tool into the SDS plus tool
holder (3) as far as it will go. Otherwise, the movability of
the SDS plus drilling tool can lead to incorrect adjustment
of the drilling depth.
– Pull the depth stop far enough out that the distance
between the drill bit tip and the edge of the depth stop
corresponds to the required drilling depth X.
Rapid shut-off (KickBack control)
– To switch the tool back on (9), release the on/off switch
and then press it twice.
position.
Inserting screwdriver bits (see figure K)
Only apply the power tool to the screw/nut when the
u
position.
tool is switched off. Rotating tool inserts can slip off.
A universal holder (22) with SDS plus shank (accessory) is
required to work with screwdriver bits.
– Clean and lightly grease the insertion end of the shank.
– Insert the universal holder into the tool holder while turn-
ing it until it locks automatically.
– Check that it is locked by pulling the universal holder.
– Insert a screwdriver bit in the universal holder. Only use
screwdriver bits that fit the screw head.
The rapid shut-off function (KickBack
Control) gives the user greater control
over the power tool and offers them bet-
ter protection than power tools that do
not have KickBack Control. The power
tool will switch off if it suddenly and un-
foreseeably rotates around the drilling
axis.
Bosch Power Tools