Operating Instruction DD 350-CA (01)

English 17
Malfunction Possible cause Action to be taken
The service indicator blinks.
Service interval exceeded. ▶ Bring the diamond core drilling
machine to Hilti.
The drilling speed is decreas-
ing.
Maximum drilling depth has been
reached.
▶ Remove the core and use a core
bit extension.
The core is stuck in the diamond
core bit.
▶ Remove the core.
Wrong core bit specification for the
base material.
▶ Select a more suitable diamond
core bit specification.
High steel content (indicated by
clear water containing metal cut-
tings).
▶ Select a more suitable diamond
core bit specification.
The diamond core bit is defective. ▶ Check the diamond core bit
for damage and replace it if
necessary.
Wrong gear selected. ▶ Select the right gear.
Contact pressure is too low. ▶ Increase the contact pressure.
The machine has too little power. ▶ Select the next lower gear.
The diamond core bit is polished. ▶ Sharpen the diamond core bit
by drilling into a sharpening
plate.
The volume of water is too high. ▶ Reduce the volume of water us-
ing the water volume regulator
(ensure that the volume of water
is at least 0.5 l/min as required).
The water flow rate is too low. ▶ Check the water supply to
the diamond core bit or,
respectively, increase the water
flow by adjusting the water flow
regulator.
The carriage lock is engaged. ▶ Release the carriage locking
mechanism.
The diamond core bit doesn’t
rotate.
The diamond core bit has become
jammed in the base material.
▶ Use an open-end wrench to
release the diamond core bit:
Disconnect the supply cord 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.
Stand-guided drilling
▶ Turn the handwheel and try to
release the diamond core bit
by moving the carriage up and
down.
The handwheel can be turned
without resistance.
The shear pin is broken. ▶ Replace the shear pin.
The diamond core bit can’t be
fitted into the chuck.
The core bit connection end or
chuck is dirty or damaged.
▶ Clean and grease the connec-
tion end and/or the chuck or
replace these parts.
Water escapes at the water
swivel or gear housing.
The water pressure is too high. ▶ Reduce the water pressure.
Printed: 18.10.2017 | Doc-Nr: PUB / 5236054 / 000 / 02