Hilti DD 30-W Original Operating Instructions page 47

8. Check that the core bit is not in contact with the working surface and then press the control switch half
way (this activates hole-starting speed).
9. If you are drilling upwards, wait until the core bit has filled with water.
◁ This will help to ensure that the core bit is cooled and avoid damage cause by dry drilling.
10. Press the core bit gently against the working surface.
◁ After switching on (pressing the control switch half way), the drilling machine runs at the slower
hole-starting speed in order to reduce the tendency of the core bit to "wander" when starting the
hole.
11. Press the control switch fully as soon as the core bit begins to bite and drill smoothly.
◁ The core bit can rotate at maximum speed as soon as the control switched is pressed fully.
Note
Adjust the pressure applied so that the drilling machine continues to run at full speed. Optimum
drilling performance will then be achieved (the drilling performance indicator lights green).
Application of higher pressure will not increase the rate of drilling progress (the drilling performance
indicator lights red).
Note
Guide the core bit carefully, keeping it straight in the hole. Tilting the core bit in the hole may result
in reduced drilling performance.
Note
Always take care to ensure that the water flow rate is set correctly. Check the water flow by
keeping an eye on the flow rate indicator.
6.2 Drilling using the drill stand
WARNING
Water running out presents a risk of electric shock! The spray guard cannot be used when the
machine is mounted on the drill stand. The machine is therefore not protected against entry of water
when mounted on the drill stand.
▶ Never drill in an upwards direction with the machine mounted on the drill stand!
WARNING
Risk of accident! When drilling penetrations through walls or floors/ceilings, the core or fragments of
material may drop out and fall down on the other side.
▶ Take the necessary safety precautions on the other side of the wall or below the floor/ceiling before
drilling penetrations.
WARNING
Risk of injury Hazard presented by a falling diamond core drilling machine.
▶ When drilling horizontally, the drill stand must be secured additionally by a chain.
1. If you are using a wet/dry industrial vacuum cleaner, connect the suction system ( → page 36) and follow
steps 1 to 3 in the section on hand-guided drilling ( → page 38).
2. Plug the supply cord into the power outlet and switch on the ground fault circuit interrupter (PRCD) (see
section on connecting electric power and water → page 37).
3. Release the carriage locking mechanism.
4. Use the hand wheel to move the carriage down until the water collector is in contact with the working
surface.
5. Press the machine's control switch and hold it in this position. Set the water regulation lever to the
desired water flow rate and then release the control switch.
Note
The water supply (water on/off) is controlled automatically by the machine's control switch. The
water flow rate can be preset by turning the water regulating lever before starting drilling or
regulated while drilling is in progress (minimum water flow rate when the regulating lever is in the
"closed" position is approx. 0.3 l/min).
Printed: 20.12.2016 | Doc-Nr: PUB / 5283477 / 000 / 03
English 39