Hilti DD 120 Original Operating Instructions

*274865*
274865 English 35
9 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.
9.1 The diamond core drilling machine is not in working order
Malfunction Possible cause Action to be taken
The service indicator shows
nothing.
The PRCD isn’t switched on. ▶ Check that the PRCD is
functioning and switch it on.
Interruption in the electric supply. ▶ Plug in another electric tool or
appliance and check whether it
works.
▶ Check the plug connections,
supply cord, power supply line
and main supply fuse.
The on / off switch is defective. ▶ Have the machine repaired by
Hilti Service.
Fault in the electronics. ▶ Have the machine repaired by
Hilti Service.
Water in the motor. ▶ Allow the diamond core drilling
machine to dry out completely
in a warm, dry place.
Service indicator lights.
The carbon brushes are worn out. ▶ Replace the carbon brushes.
→ page 34
Service indicator flashes.
Motor speed error. ▶ Have the machine repaired by
Hilti Service.
The drilling performance indi-
cator flashes red.
The motor has overheated. ▶ Wait a few minutes until the
motor has cooled down or
allow the diamond core drilling
machine to run under no load in
order to speed up the cooling
process. Switch the diamond
core drilling machine off and
then on again.
Overload error. ▶ Switch the diamond core drilling
machine off and then on again.
Theft protection indicator
blinks.
The diamond core drilling machine
has not been unlocked (machines
with optional theft protection sys-
tem).
▶ Use the TPS key to unlock the
diamond core drilling machine.
9.2 The diamond core drilling machine is in working order
Malfunction Possible cause Action to be taken
Service indicator lights.
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.
▶ Have the carbon brushes
replaced at the next opportunity.
Printed: 09.08.2019 | Doc-Nr: PUB / 5069516 / 000 / 07

Hilti DD 120 Specifications

General

Brand	Hilti
Model	DD 120
Category	Drill
Language	English