Berner 367866, Safety And Users Manual, Page: 30 / 88

English 12
07-2020
▪ if you want to operate in the wet mode, open the
valve (the valve is open when the handle is parallel
to the water stream). The water should come out
from the centre of the core bit.
▪ if you use the core drill hand-held, using a start
drilling device, begin to drill into the material,
pressing lightly. Let the diamond segments drill
about 1 cm deep into the material. This operation is
very important because, if correctly carried out,
leads to a perfect centering and makes drilling
easier. After this some start drilling devices need to
be removed;
▪ if you use the core drill with a stand, fix the stand on
the material to be drilled and than mount the core
drill to the stand, according to the instructions
provided by the manufacturer of the stand. Then
switch on the core drill, keeping the core bit not in
contact with the material to be drilled. After this
operation, using the moving system of the stand,
move the core drill and the rotating core bit closer
to the material and, pressing lightly, drill about 1 cm
into the material. This operation is very important
because, if correctly carried out, leads to a perfect
centering and makes drilling easier. In any case,
refer to directions provided by the manufacturer of
the stand;
▪ after the centring operation, increase the forward
speed. On one hand, a too low forward speed leads
to polishing of diamond sectors, decreasing their
drilling capacity. On the other hand, a too high
forward speed, leads to a quick segments wear.
▪
when drilling, make sure that the rotation axis of the
core bit doesn’t move and avoid any possible
movement of it. When the core bit rotation axis
moves, the friction between the wall of the hole and
the core bit leads to a considerable power loss.
▪ if you can not continue drilling, you can make a new
hole around the old one (over-drilling), keeping the
same rotation axis. The diameter of the new hole
must be at least 15-20 mm bigger than the diameter
of the old one;
▪
drilling materials containing wood, cork, rubber,
foam polystyrene can lead to problems moving
forward the core bit. If you have this kind of
problems, pull the core out of the hole and remove
all the materials listed before that do
n’t allow the
core bit to go on and then continue with drilling
operations;
▪ in case the electric power goes off, set the switch to
the off position, preventing the machine from
accidentally self starting;
▪
do not touch the core bit after performing a drill.
The core bit can be very hot and cause severe
burns.
Mechanical clutch
Warning: the unexpected block of the core bit
rotation can cause an heavy jerk at your arms.
The maximum force of this jerk at your arms, accordingly
with the safety regulation, can not exceed 40 Kg. Be always
ready to resist this kind of jerk and to quickly release the
switch. Your BERNER core drill is equipped with a safety
mechanical clutch that comes into operation in case of
sudden stop of the core bit rotation. Despite your drill is
equipped with this device, you must always be watchful and
be ready to resist the jerk and release the switch. The block
of the core bit rotation is dangerous for the operator
Electronic devices
Your core drill is equipped with a BERNER multifunction
electronic device that includes a soft-start and an electronic
clutch.
▪
the soft-start allows the motor soft-start, reduces
current peak that occurs when you switch the motor
on, helps you when you begin drilling, allowing
gradual core bit rotation and avoiding jerks at your
arm, and allows you to use your core drill
connected to the household electric outlet equipped
with automatic switch;
▪ the electronic clutch cuts off power to the motor in
case of excessive overload, increasing the operator
safety and preventing damage to the motor. When
the overload is over, the device gives back power to
the motor that begins working again;
▪
if the electronic clutch operates frequently means
that the core drill is not used properly. Possible
causes can be a not suitable forward speed, an
excessive friction between the core bit and hole
wall or an excessive drilling depth.
Drilling deeper than the core bit length
If you want to make an hole deeper than the core bit length
proceed as follows:
▪ drill till the end of the core bit;
▪
pull the core bit out of the hole and remove the
core;
▪
place a proper core bit extension between the core
bit and the core drill thread;
▪
insert the core bit in the hole and proceed drilling.
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Periodic maintenance
▪ at the end of the work, after having removed the
core bit, blow compressed air inside the rotating
motor in order to remove dust and powder. Do this
operation wearing protective goggles;
▪ before starting any other cleaning, maintenance or
lubrication operation make sure that the core drill is
unplugged;
▪
keep lubricate the core-bit shaft thread;
▪
keep your core drill clean and dry, in particular its
handles;
▪ never use solvents or other harsh chemicals for
cleaning your core drill;
▪ after use put your core drill in a dry, safe and
inaccessible to children place;
▪
gears are lubricated by lubricating oil and grease
which are suited for any external temperature. You
don’t have to check the oil level or to fill it up.
▪
always unplug the core drill during check or
replacement;
▪
never unplug the core drill by pulling the cord;
▪
inspect often feeding cable and extension cords,
mak
ing sure that they don’t have any damage like
cuts, abrasions or live conductors. If you find a
damage, ask a BERNER authorized service centre
for replacement;
▪
do not use the core drill with damaged components
or with malfunctions, in particular when the switch
doesn’t work properly. In these cases, ask a
BERNER authorized service centre for
replacement.