Kernlochbohrer DKB Series User manual

Operating instructions
DKB-132/2H
Kernlochbohrer GmbH
Geigersbühlweg 52
72663 Großbettlingen
Tel. [phone]
Email: [e-mail]
Version 0 6. Output 05/2023

Content
Introduction and description 3
About this guide 3
Thanks to the buyer 4
Explanation of symbols 4
Safety regulations 4
Product structure 8
Technical data 9
Use and care 9
Precautions 10
Preparation 10
Operation on drill rig 11
Mounting and assembly of core drill rig and stand 11
Changing drill bits 11
Cooling of drill and machine 12
Electrical connection 13
Water supply connection 14
Gearbox shift 14
Drilling 15
Electronic overload protection 17
Mechanical overload protection 17
Shutdown carbons 18
Segment break 18
After drilling 18
Daily maintenance of the power tool 19
Behaviour in the event of disruptions 20
Troubleshooting 21
Environmental protection 22
Noise / Vibration 22
Warranty 23
Exploded view 24
EC Declaration of Conformity 26
2

Introduction and description
The core drilling equipment of the DKB series is intended for professional use and
may only be operated by instructed persons. Strictly adhere to the instructions in
the operating manual to avoid electric shock or fire.
Our company declines all responsibility in the event of violations of the operating
instructions that may result in injury or machine damage. In addition, all currently
applicable regulations of the Accident Prevention Regulations (UVV) and the
Employer's Liability Insurance Association (BG) must be observed.
In conjunction with the appropriate drill bits, the machine is intended for drilling
concrete, stone and masonry in wet and dry cutting. However, you must ensure that
you select the correct drill bit for the corresponding drilling technique in each case.
The machine may only be serviced by persons who have the appropriate
qualification and certification.
About this guide
These operating instructions are for the models
DKB-132/2H
Check the machine model against the type plate.
3

Thanks to the buyer
Thank you for purchasing a core drill of the DKB series from Kernlochbohrer GmbH.
Please read the operating instructions carefully and observe the safety instructions.
By operating it correctly, you will fully appreciate the outstanding performance of our
products. Keep this manual in a safe place for future reference.
If you have any questions about the operation of the core drill, please contact the
company Kernlochbohrer GmbH directly. We are always available to answer your
questions.
Note:
Kernlochbohrer GmbH reserves the right to change the design and appearance of
the products and their operating instructions. Future changes to the operating
instructions will be made without prior notice.
Explanation of symbols
Warning of general danger. Failure to observe these safety precautions and
instructions may result in electric shock, fire and/or serious injury.
Safety regulations
❖Read all precautions before commissioning and keep the operating
instructions. In addition, all currently applicable regulations of the Accident
Prevention Regulations (UVV) and the Employer's Liability Insurance
Association (BG) must be observed.
❖Please follow the operating instructions carefully, as failure to observe these
safety precautions and instructions may cause electric shock, fire and/or
serious injury.
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1. Keep your work area clean and well lit. Disorder or unlit work areas can lead to
accidents.
2. Do not work with the power tool near flammable liquids, gases or dust. Power
tools produce sparks that can ignite dust or vapours, causing explosions.
3. Keep children and other people away while using the power tool. If you are
distracted, you may lose control of the tool.
4. Be attentive, work with concentration and pay attention to what you are doing.
Do not use a power tool when you are tired or under the influence of drugs,
alcohol or medicines. A moment of inattention can lead to serious injury.
5. Wear suitable protective equipment and always safety glasses. Wearing
suitable protective equipment such as a dust mask, non-slip safety shoes, hard
hat or hearing protection reduces the risk of injury.
6. Avoid unintentional starting of the machine. Make sure that the power tool is
switched off before connecting it to the power supply. If you have your finger on
the switch when carrying the power tool or connect the machine to the power
supply when it is switched on, this can lead to accidents.
7. Remove adjusting tools or spanners before switching on the power tool. A tool
or spanner that is on a rotary device can cause injury.
8. Avoid unusual postures. Make sure you stand securely and keep your balance
at all times. Do not work on a ladder. This will help you control the power tool in
unexpected situations.
5

9. Wear appropriate clothing. Do not wear loose clothing or jewellery. Keep hair,
clothing and gloves away from moving parts. Loose clothing, jewellery or long
hair can be caught by moving parts.
10. Do not overload the appliance. Use the appropriate power tool for your work.
With the appropriate power tool, you will work better and more gently in the
specified power range.
11. Do not use a power tool whose switch is damaged. A power tool that cannot be
switched on and off is dangerous and must be repaired.
12. Unplug the appliance from the mains before making any adjustments, replacing
accessories or putting the appliance aside. This safety measure prevents the
power tool from starting unintentionally.
13. Keep unused power tools out of reach of children. Do not allow persons to use
the appliance who are not familiar with it or have not read these instructions.
Power tools are dangerous when used by inexperienced persons.
14. Note that the voltage must not exceed +/-5% of the nominal voltage. Higher
voltages can cause irreparable damage. Note that higher voltage peaks are not
generated when operating the machine via a generator.
15. The plug of the power tool must match the socket. Do not change the plug
under any circumstances. Do not use adapter plugs with earthed forces.
Unmodified plugs and matching sockets reduce the risk of electric shock.
16. Avoid body contact with earthed surfaces or earthed components such as pipes,
radiators, areas and refrigerators.
17. Do not expose power tools to rain or wet conditions. Water entering a power tool
increases the risk of electric shock.
6

18. Never use the cord to carry or pull the power tool or to unplug it from the wall
socket. Keep it away from heat, oil, sharp edges or moving parts. Damaged,
crushed or twisted cables increase the risk of electric shock.
19. When using a power tool outdoors, only use an extension cord that is suitable
for outdoor use. Using a cord that is suitable for outdoor use reduces the risk of
electric shock. When using with an extension cord, also make sure that the
extension cord has the same cross-section as the cord on the machine.
20. The use of products such as cutters, grinders, drills that work sand or other
materials can generate dust and fumes that may contain hazardous chemicals.
Check the type of material you are going to work on and use a suitable
respirator.
21. Non-approved spare parts and any modification are prohibited on our products.
22. If operating a power tool in a humid environment is unavoidable, use a ground
fault circuit interrupter. The use of a ground fault circuit interrupter reduces the
risk of electric shock.
23. If a hoover and extractor are required, ensure that they are connected and used
correctly. The use of a hoover can reduce dust-related hazards.
7

Product structure
1. Tool holder 6. Start switch
2. Oil seal 7. Main handle
3. Water connection 8. Guide handle
4. Motor housing 9. Switch for gears 1 / 2
5. Cruise control
8
1
3
4
2
9
8
7
6
5

Technical data
In order to constantly improve the product, our company reserves the right to
change the technical data without prior notice.
Use and care
Only use diamond core bits that are in a sharp and undamaged condition. Properly
maintained diamond core bits with sharp cutting segments do not get bent so
quickly and are easier to guide.
Use the power tool, accessories and drill bits etc. in accordance with these
operating instructions, taking into account the working conditions and the work to be
done. Using the power tool for operations other than its intended use could lead to
a dangerous situation.
Have your power tool repaired only by qualified personnel and only with original
spare parts.
Model
DKB-132/2H
Art no.
1894/1
Power
1900W
Voltage
230V
Weight
3kg
Frequency
50-60HZ
Max. Drilling diameter brick
132mm
Max. Drilling diameter concrete without
stand
80mm
Max. Drilling diameter concrete with stand
100mm
Speed
720-1230/1780 1/min
Spindle thread
M16 (Adapter 1 ¼” UNC)
Compatible stands
KBS-200/M, 46mm clamp
holder
KBS-280/M, 46mm clamp
holder
9

Precautions
1. ALWAYS wear hearing protection! When using drill motors, the loud drilling
noise in the working area can cause hearing damage.
2. When drilling, keep a sufficient distance from the core drill and do not touch any
rotating parts. Protect the danger zone and keep children and other persons
away from it. Falling and splashing parts can cause injuries.
3. This diamond core drill is intended for professional use only and may only be
operated by trained personnel. Appropriate use of the core drill includes drilling
rock, reinforced concrete and masonry.
4. The drill motor must be checked regularly (approx. every 6 months) by a
certified electrician according to VDE.
5. When used for overhead drilling, a functional water collection ring must be used.
Make sure that no water can get into the motor.
6. Switch off the core drill immediately if it stops for any reason. After you have
determined and eliminated the cause and carried out a visual inspection of the
drill and core bit, the core drill can be restarted.
Preparation
Before each start, subject the core drill to a brief visual inspection. Also check that
the network voltage corresponds to the voltage indicated on the tool's type plate.
10

Operation on drill rig
All DKB/H series drills are designed for use with a drill stand. Only place the
machine in a stable drill stand with precise guides. Make sure that the machine
axis is parallel to the drill stand column. Only use drill stands with sufficient
stability.
Mounting and assembly of core drill rig and stand
Make sure that the core drill is not attached to the drill stand before mounting the
drill stand.
The core drill DKB-132/2H can be operated in manual mode or also with a core drill
stand. When mounting, a ᴓ46mm clamp holder must be used.
Please observe the operating instructions of the core drill rig used.
Should you use our vacuum base plate VGP-420/PRO for mounting the core drill
stand, make sure that the vacuum is at least -0.9bar and also make sure that the
seal is not worn or damaged.
Changing drill bits
A diamond core bit is a cylinder that is fitted with brazed or laser-welded segments.
There are 2 types of diamond core bits, wet drill bits and dry drill bits. These usually
have a 1 1/4UNC or an M16 female thread connection. Our DKB-H series core drills
can do both wet and dry drilling. The drive spindle has an M16 connection. An
adapter to 1 ¼" UNC is included in the accessories.
11

For easier removal of the core bit, you can apply waterproof grease to the spindle
thread of the machine.
To mount a drill bit on the core drill, simply screw it onto the drill spindle. With the
help of a copper ring (not included in the accessories) you can loosen the core bit
more easily.
Make sure that you have disconnected the mains plug from the mains before
changing or removing core bits.
The core drill and the drill bit are relatively heavy. For this reason, always wear
protective gloves to prevent injuries to your hand from the sharp tool.
For the core drill DKB-132/2H, use an open-end spanner with SW24 for loosening.
Never loosen the core bit with (hammer) blows, as this will damage the core drill.
After mounting the drill on the machine, let it run briefly and check the radial run-out
of the core bit.
Cooling of drill and machine
The gearbox of the drill motor has splash lubrication for cooling.
The diamond segments of the wet drill bit are cooled with water.
The electric motor is air-cooled.
12

Electrical connection
To reduce the risk of electric shock and to protect the operator, the core drill rig
DKB-132/2H must only be operated via a Portable Residual Current Device, or
PRCD personal circuit breaker.
After connecting to the power supply, first press the
"RESET" button on the PRCD circuit breaker to energise
the circuit to the core drill. In the event of a voltage drop,
the PRCD circuit breaker switches off and must be
switched on again as soon as the power supply is
restored. The fault current at which the PRCD circuit
breaker switches off is 10mA.
Never place or put the PRCD circuit breaker in water. Before starting work, check
for proper operation by pressing the TEST button on the PRCD circuit breaker.
Never operate the core drill directly from the mains power source without a PRCD
circuit breaker.
Before commissioning, check that the mains voltage and frequency correspond to
the data on the type plate. Use only 3-core extension cable with protective earth
and sufficient cross-section (min. 2.5mm²). A cross-section that is too weak can lead
to excessive power loss and overheating of the machine and cable. The machine
has a start-up current limiter that prevents the automatic safety device from being
triggered unintentionally.
13

Water supply connection
If the core bit is not cooled sufficiently with water, the diamond segments can heat
up, which damages them and considerably reduces the service life of the core bit.
Therefore, you should always make sure that a steady water supply is ensured.
To connect the water supply, attach the quick coupling to a water hose. Use clean
water. Using water that is contaminated speeds up the process of wearing out the
water seal.
The maximum water pressure must not exceed 3 bar.
The water serves as a coolant to prevent the drill from heating up excessively
during drilling.
Dust and particles that form during drilling can clog the water supply system. If
necessary, this must be checked and cleaned.
Never let water get into the motor. It could cause an electric shock.
Gearbox shift
The core drilling machines of the DKB-132/2H have a mechanical 2-speed gearbox.
Adjust the speed of the machine to the drill diameter.
14

Turn the transmission switch to the faster or slower gear until it engages. Only
change the speed when the machine is at a standstill. If necessary, support the
shifting process by slightly turning the work spindle. If the machine stalls due to the
hardness of the material, select a lower gear to protect the machine from overload.
If the spindle does not turn after starting or if there is noise, the gear may not be
engaged properly. Stop the machine immediately and adjust the gear accordingly
until it engages. Turn the spindle back and forth at the same time until it is engaged.
Never change the machine to another gear during operation.
WARNING!
•Only shift the gearbox when the vehicle is at a standstill!
•Never switch over by force!
•Do not use tools such as pliers or a hammer to switch!
Drilling
Always switch on the machine without a load.
After switching on, next open the water line valve.
When water flows out of the centre of the drill, you can carefully start drilling.
Should you operate the core drill without a drill stand, start the notch by not
approaching the drill diameter with the full cutting face of the drill. Once a V-notch
cut is drilled on the drill face, line up the drill at a right angle while increasing the
feed pressure.
15

Increase the feed pressure as soon as the cutting depth reaches approx. 10mm.
Always keep an eye on the condition of the drill motor. If you notice that it starts to
smoke slightly or if you notice the smell of an electric motor, relieve the core drill by
withdrawing it from the core hole. Then continue drilling slowly and carefully. In this
way, you prevent the carbon brushes from burning off due to a prolonged overload
of the electric motor.
When you have almost reached the end of the through-hole, please reduce the feed
pressure at this point until the core bit exits at the other side.
There is vertical drilling and angle drilling. When drilling at an angle, use the angle
adjustment function of the drill stand.
If you have selected too high a speed when drilling or you are working with too high
a feed pressure, this can cause the drill to jam.
If, during the drilling process, you notice that the feed speed decreases at the same
force and the water coming out of the drill hole is clear and has some metal
splinters, you have hit rebar. Reduce the pressure on the drill bit to cut through this
easily. You can increase the pressure again when you have cut through the
reinforcing iron.
If wooden beams, thick asphalt or bitumen are cut, this will increase the current. In
this case, reduce the feed to continue drilling.
If you need to drill deeper than the effective length of your drill allows, an optional
extension can be used. First, drill only as far as the usable length of the crown
allows. Remove the crown and loosen the drill core from the hole without moving
the core drill unit. Now screw the required extension between the core bit and the
core drill unit to the drill spindle. Now attach the core bit to the extension. Push the
crown back into the drill hole.
Note:
A copper ring can facilitate loosening the diamond core bit and extension.
(Not included in the scope of delivery).
16

Electronic overload protection
The DKB-132/2H is equipped with electronic overload protection. If the core drill is
in an overload state for a long time, the machine switches off for its own protection.
Disconnect the machine from the power supply. Carry out a visual inspection of the
machine.
Mechanical overload protection
This machine is equipped with a mechanical slip clutch to protect the operator and
the machine from excessive torque forces. If the drill suddenly jams in the hole, the
safety clutch disengages and the drill spindle stops.
Make sure that the load on the clutch is not more than max. 3-4 seconds. Unload
the machine immediately. Otherwise the safety clutch may be destroyed by the high
wear. Do not continue drilling if the slipping clutch has been triggered, reduce the
feed immediately and wait until the drill bit has reached the desired speed again.
Caution!
A worn clutch must be replaced immediately by a specialist at an authorised
workshop. Working with a worn slipping clutch can lead to serious injuries.
17

Shutdown carbons
The power tool is equipped with a self-shutting carbon brush to protect the motor. If
the brushes are worn, the machine switches off automatically. In this case, both
carbon brushes must be replaced at the same time by original carbon brushes from
our shop by a trained electrician according to VDE.
Segment break
If a diamond segment, parts of the reinforcement or similar come loose during
drilling and jam the drill bit as a result, stop working on this hole and drill a hole with
the same centre and a 15-20mm larger diameter.
Note:
Do not try to finish the drilling with another core bit of the same diameter!
After drilling
When the drilling process is completed:
1. Pull the drill bit out of the hole.
2. Switch off the motor. Use the motor switch for this purpose and not the PRCD
circuit breaker.
3. Close the water supply.
18

Remove the drill core if it remains in the drill bit:
1. Disconnect the core bit from the core drill (if possible).
2. Set the drill bit vertically.
3. Tap lightly against the core drill cylinder with a wooden hammer handle or a
rubber mallet until the drill core slips out. Never hit the core bit with force against
a wall or similar or hit it with tools such as a hammer or open-ended spanner, as
otherwise the core barrel can become distorted and neither the core can be
removed nor the core bit can be reused.
Remove drill core from a blind hole
Break off the core with a wedge or lever. Lift out the core with suitable pliers or drill
a hole in the core. Screw in an eyebolt with the aid of a suitable dowel and pull out
the core from it.
Daily maintenance of the power tool
Before starting maintenance or repair work, be sure to pull out the mains plug!
Repairs may only be carried out by qualified personnel who are suitable on the
basis of their training and experience. The tool must be checked by a trained
electrician according to VDE after each repair. The power tool is designed to require
a minimum of care and maintenance. However, the following points must always be
observed:
1. Check that all screws and nuts are well tightened.
2. Check that the water seals are intact.
4. Check that the PRCD circuit breaker is working properly.
5. Always keep all accessories and the machine clean and dry.
6. The DKB-132/2H has a grease gear. It is filled with high-performance grease
MoS2 and is maintenance-free.
19

7. After approx. 300 hours of operation, the carbon brushes must be checked by
a trained electrician according to VDE and replaced if necessary (only use
original carbon brushes from our shop).
8. If cooling water leaks uncontrollably from the oil seal, have it replaced by a
specialist workshop and only use original spare parts from our shop.
9. After finishing the work, remove the drill bit and then clean the entire machine.
Do not forget to lubricate the spindle thread. Keep the power tool out of reach
of children and in a dry environment.
Behaviour in the event of disruptions
Switch off the machine in case of malfunctions, disconnect it from the mains. Work
on the machine's electrical system may only be carried out by a qualified electrician
in accordance with VDE.
20