Hilti DD 120 Mode D'emploi page 41

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
The service indicator shows
nothing.
Service indicator lights.
Service indicator flashes.
The drilling performance indi-
cator flashes red.
Theft protection indicator
blinks.
9.2 The diamond core drilling machine is in working order
Malfunction
Service indicator lights.
*274865*
Possible cause
The PRCD isn't switched on.
Interruption in the electric supply.
The on / off switch is defective.
Fault in the electronics.
Water in the motor.
The carbon brushes are worn out.
Motor speed error.
The motor has overheated.
Overload error.
The diamond core drilling machine
has not been unlocked (machines
with optional theft protection sys-
tem).
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.
274865
Action to be taken
▶ Check that the PRCD is
functioning and switch it on.
▶ 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.
▶ Have the machine repaired by
Hilti Service.
▶ Have the machine repaired by
Hilti Service.
▶ Allow the diamond core drilling
machine to dry out completely
in a warm, dry place.
▶ Replace the carbon brushes.
→ page 34
▶ Have the machine repaired by
Hilti Service.
▶ 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.
▶ Switch the diamond core drilling
machine off and then on again.
▶ Use the TPS key to unlock the
diamond core drilling machine.
Action to be taken
▶ Have the carbon brushes
replaced at the next opportunity.
English 35