Maintenance And Service; Maintenance And Cleaning - Bosch GNF Professional 20 CA Original Instructions Manual

When breaking through walls, e. g. with a rotary
hammer, most of the chipping-off of the surface
material can be avoided by first cutting in a slot
with maximum cutting depth.
For cutting expecially hard material, e. g., con-
crete with high pebble content, the diamond
cutting disc can overheat and become damaged
as a result. This is clearly indicated by circular
sparking, rotating with the diamond cutting
disc.
In this case, interrupt the cutting process and al-
low the diamond cutting disc to cool by running
the machine for a short time at maximum speed
with no load.
Noticeable decreasing work progress and circu-
lar sparking are indications of a diamond cutting
disc that has become dull. Briefly cutting into
abrasive material (e. g. lime-sand brick) can re-
sharpen the disc again.
Parallel Guide (GNF 20 CA)
To cut additional parallel slots, press the guide
bolt 15 of the parallel guide 14 down into the al-
ready cut slot and then carry out the cutting pro-
cedure.
Information on Structures
Slots in structural walls are subject to the
Standard DIN 1053 Part 1, or country-specific
regulations.
These regulations are to be observed under all
circumstances. Before beginning work, consult
the responsible structural engineer, architect or
the construction supervisor.
The permitted slot depth and width depends on
the slot length, wall thickness and the building
material used.
Bosch Power Tools

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.
After finishing work, dismount the clamping fix-
tures and clean all clamping parts as well as the
protective cover.
Service Indicator 11 (GNF 35 CA)
When the carbon brushes are worn out, the ma-
chine switches itself off. This is indicated ap-
prox. 8 hours beforehand by the lighting or
blinking of the service indicator 11. The machine
must then be sent to an after-sales service
agent. Addresses are listed in the Section "Af-
ter-sales service and customer assistance".
WARNING! Important instructions for con-
necting a new 3-pin plug to the 2-wire cable.
The wires in the cable are coloured according to
the following code:
Do not connect the blue or brown wire to the
earth terminal of the plug.
Important: If for any reason the moulded plug is
removed from the cable of this power tool, it
must be disposed of safely.
If the machine should fail despite the care taken
in manufacturing 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 include the 10-digit article
number given on the type plate of the machine.
English | 29
1 609 929 K57 | (27.11.07)