Troubleshooting - Hilti DD 30-W Original Operating Instructions

6. Run in the carbon brushes by letting the machine run under no load for at least 1 minute without
interruption.
➥ The indicator lamp will go out after a running time of approx. 1 minute with the new carbon brushes.
7.2 Cleaning the water flow sight glass
Pay attention to cleanliness at your workplace when cleaning the sight glass. Take care to prevent dirt
entering the inside of the water flow rate indicator while the glass is being cleaned.
1. Use a Torx TX 15 screwdriver to remove the two screws at the sight glass.
2. Lift the glass away.
3. Remove the water flow rate impeller, complete with axle.
4. Remove any dirt particles by flushing under running water.
5. Before fitting the parts, check the sight glass seal for damage and replace it if necessary.
6. Make sure that the seal is positioned exactly in its seat. The seal may otherwise be pinched between the
plastic parts when the sight glass is fitted, thereby damaging the seal and resulting in leakage.
7. Refit the impeller complete with its axle.
8. Press the sight glass back into place.
9. Insert the sight glass retaining screws (Torx screws) and tighten them securely.
8

Troubleshooting

If the trouble you are experiencing is not listed in this table or you are unable to remedy the problem by
yourself, please contact Hilti Service.
8.1 The diamond core drilling machine is in working order
Malfunction
The service indicator lights.
The diamond core drilling
machine doesn't achieve full
performance.
The diamond core bit doesn't
rotate.
The drilling speed is decreas-
ing.
*2048397*
Printed: 05.02.2019 | Doc-Nr: PUB / 5283477 / 000 / 05
Possible cause
The carbon brush wear limit has
almost been reached. The diamond
core drilling machine will continue
to run for a few hours until it shuts
down automatically.
The carbon brushes have been
changed and must be run in.
Supply network fault – undervolt-
age occurred.
The diamond core bit has become
jammed in the base material.
Maximum drilling depth has been
reached.
The core is stuck in the diamond
core bit.
2048397
Action to be taken
▶ Have the carbon brushes
replaced at the next opportunity.
▶ Run in the carbon brushes by
letting the machine run under
no load for at least 1 minute
without interruption.
▶ Check whether other power
consumers are disrupting the
power supply from the network
or generator.
▶ Check the length of the exten-
sion cord used.
▶ Guide the diamond core drilling
machine in a straight line.
▶ Use an open-end wrench to
release the diamond core bit:
Disconnect the mains plug from
the power outlet. Grip the
diamond core bit with a suitable
open-end wrench close to the
connection end and release the
diamond core bit by rotating it.
▶ Remove the core and use a
longer core bit.
▶ Remove the core.
English 43