Hilti DD 120 Mode D'emploi page 18

7.5 Drilling with use of the water collection system
and wet-type industrial vacuum cleaner
(accessories) 8
en
WARNING
Water must not be allowed to run over the motor and
cover.
WARNING
The diamond core bit fills with water during overhead
drilling. Drilling upwards at an angle is not permissible
(the water collector cannot function correctly).
NOTE
The vacuum cleaner must be switched on manually be-
fore drilling is started and switched off manually once
drilling is completed.
1. Switch the vacuum cleaner on. Do not use the
vacuum cleaner in automatic mode.
2. Connect the water supply.
3. Open the water flow regulator.
4. Press the on/off switch on the machine (position "I").
The drilling performance indicator lights orange.
5. Release the carriage brake.
6. Turn the handwheel until the diamond core bit is in
contact with the base material.
7. Apply only light pressure until the diamond core bit
has centered itself and then increase the pressure.
8. Regulate the contact pressure while observing the
drilling performance indicator.
NOTE The drilling performance indicator lights or-
ange after switching on. Optimum drilling perfor-
mance is achieved when the drilling performance
indicator shows a green light. If the drilling per-
formance indicator shows a red light, reduce the
pressure applied to the core bit.
14
7.6 Switching off 9
WARNING
Exercise caution when drilling overhead : The diamond
core bit fills with water during overhead drilling. As a
first step, carefully allow the water to drain away
after completing overhead drilling. This is done by
disconnecting the water supply from the water flow
regulator and draining the water by opening the water
flow regulator. Do not allow the water to run over the
motor and cover.
1. Close the water flow regulator.
2. Remove the diamond core bit from the hole.
3. Engage the carriage brake.
4. Switch the drilling machine off.
5. Switch off the industrial vacuum cleaner.
7.7 Procedure in the event of the core bit sticking
The safety clutch releases in the event of the core bit
binding and sticking. Following this, the motor is switched
off by the electronic control system. If the user takes no
action, the electronic control system switches the motor
on twice automatically. If the core bit still can't be freed,
the electronic control system switches the motor off for
90 seconds. The core bit can be released by taking the
following action:
7.7.1 Using an open-end wrench to release the
core bit
1. Disconnect the supply cord plug from the power
outlet.
2. Grip the core bit with a suitable open-end wrench
close to the connection end and release the core bit
by rotating it.
3. Plug the machine's supply cord into the power out-
let.
4. Resume the drilling operation.
7.7.2 Using the spider wheel to release the core bit
1. Disconnect the supply cord plug from the power
outlet.
2. Use the spider wheel to rotate the core bit and
release it from the base material.
3. Plug the machine's supply cord into the power out-
let.
4. Resume the drilling operation.
7.8 Dismantling
CAUTION
Disconnect the supply cord plug from the power out-
let.
1. For instructions on removing the diamond core bit,
please refer to the section "Removing the diamond
core bit".
2. Remove the core if necessary.