Bosch GNF Professional 20 CA, Original Instructions Manual

Page: 28 / 163

28 | English
1 609 929 K57 | (27.11.07) Bosch Power Tools
Reduced starting current
The electronic reduced starting current limits
the power consumption when switching the tool
on and enables operation from a 13 ampere
fuse.
Constant Electronic Control
Constant electronic control holds the speed
constant at no-load and under load, and ensures
uniform working performance.
Overload Protection
When overloaded, the motor comes to a stop.
Relieve the load on the machine immediately
and allow to cool down for approx. 30 seconds
at the highest no-load speed.
Restarting Protection (GNF 35 CA)
The restarting protection feature prevents un-
controlled restarting of the machine after an in-
terruption in the power supply.
To
restart the operation , switch the On/Off
switch 10 to the Off position and start the ma-
chine again.
Note: Check the function of the restarting pro-
tection feature regularly by having the mains
plug pulled during operation and plugged in
again afterwards.
Working Advice
f
Exercise caution when cutting slots in
structural walls; see Section “Information
on Structures ”.
f
Do not strain the machine so heavily that it
comes to a standstill.
f
Clamp the workpiece if it does not remain
stationary due to its own weight.
f
The machine may only be used for dry cut-
ting.
– Adjust the cutting depth, see section “Pre-se-
lecting the Cutting Depth”. To compensate
inaccuracies that occur when breaking away
the fin, the cutting depth must be set approx.
3 mm deeper than the requested slot depth.
– Place the machine with the chaser rollers 7
on the surface to be worked. The cutting unit
must be in the uppermost position.
– Switch on the machine.
– Push the release button
3 upwards to release
the cutting unit. Slowly lower and plunge the
cutting unit into the material.
– Guide the machine with both handles, apply-
ing moderate feed, suited to the material be-
ing worked.
– The machine must always work in an up-
grinding motion. Otherwise, the danger ex-
ists of it being pushed
uncontrolled out of
the cut. Guide the machine in the direction of
the working-direction arrow
8 .
– The machine can be both pushed or pulled in
the cutting direction. Vertical slots can easily
be cut by pulling the machine from top to
bottom.
– After finishing the working procedure, swivel
the cutting unit out of the slot with the ma-
chine still running, until the cutting unit en-
gages in the uppermost position.
– Switch the power tool off.
Do not brake coasting diamond cutting discs by
applying sideward pressure.
f
Diamond cutting discs become very hot dur-
ing operation; do not touch them until they
have cooled down.
Remove the remaining fin of the material with
the break-out tool
21 .
Curved cuts are not possible, as the diamond
cutting discs could jam in the material.
When cutting through plate materials, ensure
that the materials are firmly backed on a surface
or supported.
21
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