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24
English
2279864
*2279864*
Malfunction
Possible cause
Action to be taken
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 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.
▶
If using a drill stand: Turn the
hand wheel and try to release
the diamond core bit by moving
the carriage up and down.
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 water flow rate is too high.
▶
Reduce the water flow rate
by adjusting the water flow
regulator.
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.
Dust is hindering drilling progress.
▶
Use a suitable dust removal
system.
The hand wheel 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.
Water escapes from the
chuck during operation.
The diamond core bit isn’t securely
tightened in the chuck.
▶
Tighten the diamond core bit
securely.
▶
Remove the core bit. Rotate the
diamond core bit approx. 90°
about its own axis. Refit the
diamond core bit.
Summary of Contents for DD 250-CA
Page 1: ...DD 250 CA English 1 Fran ais 26 Espa ol 53 Portugu s 81...
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Page 116: ...108 Portugu s 2279864 2279864...
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Page 120: ...Hilti registered trademark of Hilti Corp Schaan Pos 3 20201023 2279864 2279864...