Starting Operation; Working Advice - Bosch Professional GDR 10,8-LI Originalbetriebsanleitung

OBJ_DOKU-27585-004.fm Page 15 Thursday, November 13, 2014 6:02 PM

Starting Operation

Inserting the battery
Note: Use of batteries not suitable for the machine can lead to
malfunctions of or cause damage to the power tool.
Set the rotational direction switch 8 to the centre position in
order to avoid unintentional starting. Insert the charged bat-
tery 7 into the handle so that it can be felt to engage and faces
flush against the handle.
Reversing the rotational direction (see figure C)
The rotational direction switch 8 is used to reverse the rota-
tional direction of the machine. However, this is not possible
with the On/Off switch 9 actuated.
Right rotation: For driving in screws and tightening nuts,
press the rotational direction switch 8 through to the left
stop.
Left Rotation: For loosening and unscrewing screws and
nuts, press the rotational direction switch 8 through to the
right stop.
Switching On and Off
To start the machine, press the On/Off switch 9 and keep it
pressed.
The power light 4 lights up when the On/Off switch 9 is slightly
or completely pressed, and allows the work area to be illumi-
nated when lighting conditions are insufficient.
To switch off the machine, release the On/Off switch 9.
To save energy, only switch the power tool on when using it.
Adjusting the Speed
The speed of the switched-on power tool can be variably ad-
justed, depending on how far the On/Off switch 9 is pressed.
Light pressure on the On/Off switch 9 results in a low rotation-
al speed. Further pressure on the switch results in an increase
in speed.
Battery Charge-control Indication
The battery charge-control indicator 10 consists of three
green LEDs, and indicates the charge condition of the battery
for a few seconds when the On/Off switch 9 is pressed half-
way or fully.
LED
Continuous lighting 3 x green
Continuous lighting 2 x green
Continuous lighting 1 x green
Flashing light 1 x green
Temperature Dependent Overload Protection
When using as intended for, the power tool cannot be subject
to overload. When the load is too high or the allowable battery
temperature range is exceeded, the speed is reduced. The
power tool will not run at full speed until reaching the allow-
able battery temperature.
Bosch Power Tools
Protection Against Deep Discharging
The lithium-ion battery is protected against deep discharging
by the "Electronic Cell Protection (ECP)". When the battery is
empty, the machine is switched off by means of a protective
circuit: The inserted tool no longer rotates.

Working Advice

 Apply the power tool to the screw/nut only when it is
switched off. Rotating tool inserts can slip off.
The torque depends on the impact duration. The maximum
achieved torque results from the sum of all individual torques
achieved through impact. The maximum torque is achieved
after an impact duration of 6–10 seconds. After this dura-
tion, the tightening torque is increased only minimally.
The impact duration is to be determined for each required
tightening torque. The actually achieved tightening torque is
always to be checked with a torque wrench.
Screw Applications with Hard, Spring-loaded or Soft Seat
A test in which the achieved torques in an impact series are
measured and transferred to a diagram will produce the curve
of a torque characteristic. The height of the curve corre-
sponds with the maximum reachable torque, and the steep-
ness indicates the duration in which this is achieved.
A torque gradient depends on the following factors:
– Strength properties of the screws/nuts
– Type of backing (washer, disc spring, seal)
– Strength properties of the material being screwed/bolted
together
– Lubrication conditions at the screw/bolt connection
The following application cases result accordingly:
– A hard seat is given for metal-to-metal screw applications
with the use of washers. After a relatively short impact du-
ration, the maximum torque is reached (steep characteris-
tic curve). Unnecessary long impact duration only causes
damage to the machine.
– A spring-loaded seat is given for metal-to-metal screw ap-
plications, however with the use of spring washers, disc
springs, studs or screws/nuts with conical seat as well as
when using extensions.
– A soft seat is given for screw applications, e. g., metal on
wood or when using lead washers or fibre washers as back-
Capacity
ing.
≥ 2/3
For a spring-loaded seat as well as for a soft seat, the maxi-
≥1/3
mum tightening torque is lower than for a hard seat. Also, a
< 1/3
clearly longer impact duration is required.
Reserve
English | 15
1 609 92A 0XU | (13.11.14)