Hilti DD-750 HY Mode D'emploi page 30

Setting up, checking and operating the hydraulic drilling system
1. Points to check before beginning drilling
● The rig must be securely fastened and all quick-release connections tight.
● Hydraulic hoses must be connected and secured.
● The core bit or core bit extension must be tightened securely.
● The correct coring speed must be selected (change gear only when rotation has stopped).
● Check the electric power and water connections and ensure that they are ready for use.
● The working area must be secured (cordoned off where necessary).
-DANGER-
Do not use damaged core bits. Check the core bits for chipping, cracks, or heavy wear each
time before use. Do not use damaged tools. Fragments of the workpiece or a broken core bit
may be ejected and cause injury beyond the immediate area of operation.
-NOTE-
Diamond core bits must be replaced when the cutting performance and/or rate of drilling progress
drops significantly. This generally is the case when the segments reach a height of less than 2 mm.
2. Operating the drilling system
● Ensure that all levers / oil flow switches are set to "0" (OFF) and the maximum current input is
set to 50 amps on the D-LP32.
● Open the water valve and switch on the hydraulic unit – "I" (ON).
● Release the feed movement locking device and bring the core bit into contact with the concrete
surface.
● Start the DD-750 HY drive unit: D-LP15 - Set the valve control lever on the DD-750 HY (and, whe-
re applicable, on the D-RC15) to the I = ON position. D-LP 32 - Set the valve control lever on the
DD-750 HY to the I = ON position, start the unit by way of the remote control and set the desired
oil flow rate (max. 60 l/min).
● Begin drilling gently, using manual or automatic feed control, and then increase to full power.
● Adjust the feed pressure so that the core bit maintains a constant, high speed (r.p.m.).
● After breaking through, withdraw the core bit from the hole while rotating and with water still flow-
ing. Switch off the water and stop the motor. Remove the core.
● Switch off the hydraulic unit, disassemble the equipment and clean the parts or set up the rig at
the next location.
3. Additional information and tips
● Reduce speed (r.p.m.) when necessary, if vibration occurs or steel reinforcement is contacted.
● Water flow rate from the hydraulic unit in l/min., depending on diameter (guide):
up to approx.
150 mm dia.
approx. 5 l/min.
● Drilling performance depends on core bit diameter, the base material (concrete quality and abra-
sivness) and the number of rebars. Please refer to the documentation on diamond core bits for
information. As a rough guide, a 250 mm dia. core bit in concrete of medium abrasivness should
achieve a drilling progress rate of approx. 5 cm/min.
● Please refer to the documentation on diamond core bits for further information and tips.
● Please refer to "Disassembly and maintenance", section 5, for instructions on how to release
jammed core bits.
● An extension can be used for drilling deep holes (the core must be broken out and removed
piece by piece). Alternatively, a longer diamond core bit can be used (special lengths avail able
on request).
● Underwater drilling: The DD-750 HY can be operated under water. A water or air supply is re-
quired. Contact your Hilti specialist for further information.
● Drilling in an upwards direction is possible without any limitations. The motor unit requires no
special water protection.
● Take breaks between working and improve the blood circulation in your hands by alternately
exercising and relaxing your fingers.
● Wear the emergency off button (D-LP15) or remote control unit (D-LP 32) with the shoulder strap
while the hydraulic coring machine is in operation so that the hydraulic unit can be switched off
immediately in the event of an emergency.
30
Printed: 22.10.2015 | Doc-Nr: PUB / 5069605 / 000 / 03
up to approx.
250 mm dia.
approx. 6 l/min.
up to approx.
400 mm dia.
approx. 8 l/min.
up to approx.
750 mm dia.
approx. 10 l/min.