Hilti DCH 300 Mode D'emploi Original page 26

and run the power tool at maximum no load speed for one minute. Damaged wheels will normally
break apart during this test time.
▶ Wear personal protective equipment. Depending on application, use face shield, safety goggles
or safety glasses. As appropriate, wear dust mask, hearing protectors, gloves and shop apron
capable of stopping small abrasive or workpiece fragments. The eye protection must be capable of
stopping flying debris generated by various operations. The dust mask or respirator must be capable of
filtrating particles generated by your operation. Prolonged exposure to high intensity noise may cause
hearing loss.
▶ Keep bystanders a safe distance away from work area. Anyone entering the work area must wear
personal protective equipment. Fragments of workpiece or of a broken wheel may fly away and cause
injury beyond immediate area of operation.
▶ Hold the power tool by insulated gripping surfaces only, when performing an operation where the
cutting accessory may contact hidden wiring or its own cord. Cutting accessory contacting a "live"
wire may make exposed metal parts of the power tool "live" and could give the operator an electric
shock.
▶ Position the cord clear of the spinning accessory. If you lose control, the cord may be cut or snagged
and your hand or arm may be pulled into the spinning wheel.
▶ Never lay the power tool down until the accessory has come to a complete stop. The spinning
wheel may grab the surface and pull the power tool out of your control.
▶ Do not run the power tool while carrying it at your side. Accidental contact with the spinning
accessory could snag your clothing, pulling the accessory into your body.
▶ Regularly clean the power tool's air vents. The motor's fan will draw the dust inside the housing and
excessive accumulation of powdered metal may cause electrical hazards.
▶ Do not operate the power tool near flammable materials. Sparks could ignite these materials.
▶ Do not use accessories that require liquid coolants. Using water or other liquid coolants may result
in electrocution or shock.
Kickback and related warnings
Kickback is a sudden reaction to a pinched or snagged rotating wheel. Pinching or snagging causes rapid
stalling of the rotating wheel which in turn causes the uncontrolled power tool to be forced in the direction
opposite of the wheel's rotation at the point of the binding.
For example, if an abrasive wheel is snagged or pinched by the workpiece, the edge of the wheel that is
entering into the pinch point can dig into the surface of the material causing the wheel to climb out or kick
out. The wheel may either jump toward or away from the operator, depending on direction of the wheel´s
movement at the point of pinching. Abrasive wheels may also break under these conditions.
Kickback is the result of power tool misuse and/or incorrect operating procedures or conditions and can be
avoided by taking proper precautions as given below.
▶ Maintain a firm grip on the power tool and position your body and arm to allow you to resist
kickback forces. Always use auxiliary handle, if provided, for maximum control over kickback or
torque reaction during start-up. The operator can control torque reactions or kickback forces, if proper
precautions are taken.
▶ Never place your hand near the rotating accessory. Accessory may kickback over your hand.
▶ Do not position your body in line with the rotating wheel. Kickback will propel the tool in direction
opposite to the wheel's movement at the point of snagging.
▶ Use special care when working corners, sharp edges etc. Avoid bouncing and snagging the
accessory. Corners, sharp edges or bouncing have a tendency to snag the rotating accessory and
cause loss of control or kickback.
▶ Do not attach a saw chain, woodcarving blade, segmented diamond wheel with a peripheral gap
greater than 10 mm or toothed saw blade. Such blades create frequent kickback and loss of control.
▶ Do not "jam" the wheel or apply excessive pressure. Do not attempt to make an excessive depth
of cut. Overstressing the wheel increases the loading and susceptibility to twisting or binding of the
wheel in the cut and the possibility of kickback or wheel breakage.
▶ When wheel is binding or when interrupting a cut for any reason, switch off the power tool and hold
the power tool motionless until the wheel comes to a complete stop. Never attempt to remove the
wheel from the cut while the wheel is in motion otherwise kickback may occur. Investigate and take
corrective action to eliminate the cause of wheel binding.
▶ Do not restart the cutting operation in the workpiece. Let the wheel reach full speed and carefully
re-enter the cut. The wheel may bind, walk up or kickback if the power tool is restarted in the workpiece.
▶ Support panels or any oversized workpiece to minimize the risk of wheel pinching and kickback.
Large workpieces tend to sag under their own weight. Supports must be placed under the workpiece
near the line of cut and near the edge of the workpiece on both sides of the wheel.
20 English 2149874
*2149874*