Blastrac BG-250A User manual

Original instructions in English
OPERATING INSTRUCTIONS
BG-250E, BG-250P, BG-250A, BG-250 TWIN
VERSION 2.6

2
Inspection comments
Recurring inspections / maintenance log
*Competent person
Date / Hour counter
Findings
Repairs / Cleaning
Test
on
By*
Inspection before initial operation on: __________________________________________
By: __________________________________________
Date of initial operation: __________________________________________
Serial number & Year of manufacture: __________________________ _____________

3
Table of contents
Maintenance log 2
1. Introduction 4
2. Machine description 4
Accessories 6
3. Safety 7
3.1 Work area safety 7
3.2 Electrical safety 7
3.3 Personal safety 8
3.4 Machine safety 8
3.5 Grinding safety 9
3.6 Dust collector safety 9
3.7 Petrol version safety 9
3.8 Battery safety 10
3.9 Asbestos safety 10
3.10 Maintenance safety 11
3.11 Transport safety 11
3.12 Signs on the machine 13
4. Initial operation 14
4.1 Checkpoints of electrical safety 14
4.2 Checkpoints of machine safety 14
4.3 Checkpoints of work area 14
4.4 Manual moving of the machine 14
4.5 Changing the diamond disc 15
5. Operating 16
5.1 Before switching on 16
Checking and correcting the turning direction 16
5.2 Switching on the E-version 16
5.3 Turning off the E-version 16
5.4 Switching on the Petrol-version 17
5.5 Turning off the Petrol-version 17
5.6 Asbestos version 18
5.7 Operation with bushhammer tools 19
5.8 Operating during grinding 22
6. Maintenance 23
6.1 Replacing the flexible coupling 24
6.2 Other maintenance 25
6.3 Differential pressure switch 25
7. Troubleshooting 26
8. Technical data 27
Contact

4
1. Introduction
Before use, operators must be provided with information, instruction and training for the use of the machine
and the substances for which it is to be used, including the safe method of removal and disposal of the
material collected. All persons who are working with or maintaining this machine must read the manual
carefully and understand it fully. In case you sell the unit, hand it on to the next owner.
Keep this manual always with the machine, to enable it to be referred to at any time.
Any other work not covered by this operating manual must not be carried out.
This machine is designed for industrial use by professionals. Only authorized and trained personnel may
operate this machine. This machine is not intended for use by persons (including children) with reduced
physical, sensory or mental capabilities, or lack of experience and knowledge. Blastrac BV offers a course on
the use of the machine in order to make the operating and maintenance personnel familiar with all elements of
the machine.
2. Machine description
The Blastrac grinding machine BG-250 is an electric or petrol driven floor grinding machine for treating
horizontal surfaces. The machine has a rotating adapter plate where the diamond disc can be fixed on
The rotating parts are covered by a protection cap with a connection for a dust hose. The machine may not be
used without an adequate dust extraction system. A specially designed Blastrac dust collection system ensures
dust-free operation of the machine and clean air at the workspace.
The BG-250 can be used on almost any floor to plane, to remove coatings or glue residues or to make ready
for coatings. This machine may not be used on wood.
1
Steer handle
7
Drive motor
13
Flexible coupling
2
Cord & key for deadman switch
8
Lifting handles
14
Lever handle
3
On / Off emergency switch
9
Dust cap
15
Gas throttle
4
Socket with phase inverter
10
Brush for dust cap
16
Contact switch
5
Dust hose connection
11
Bearing unit
17
Stop button
6
Lifting eye
12
Grinding disc
18
Machine support
BG-250 E
BG-250 P

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The BG-250A can be used to remove material which can be potentially dangerous for health, for example
asbestos. The BG-250A has an additional safety feature: the under pressure meter (differential pressure
switch) which monitors the suction power of the dust collector. If the connected dust collector does not have
enough suction power or it is turned off, the machine will turn off automatically. The machine can only be
operated when the suction power is adequate to ensure that there is no release of asbestos fibres into the air.
The normal brush sealing for the dust cap has been replaced by a plastic floating shroud. This will save
precious time and money when the machine has to be cleaned after use in asbestos.
The BG-250 TWIN is specially designed for fast and easy switching between normal grinding and using
bushhammer tools. The special TWIN electromotor has 2 settings: LOW and HIGH speed. The HIGH speed
setting gives the normal RPM’s for grinding and the LOW speed setting has the perfect RPM’s for bushhammer
tools. This feature eliminates the need for changing the pulleys every time you want to switch between normal
grinding and bushhammer tool operation.
The BG-250 TWIN is standard delivered with:
+ Floating shroud for bushhammer tools (E12525)
+ Machine support Long (E12634)
BG-250 A
Floating shroud BG-250 plastic
Under pressure meter /
Differential pressure switch
BG-250 TWIN
HIGH 0 LOW

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Accessories
E01419 Disc 250mm hard Blue
E01402 Disc 250mm middle Green
E01417 Disc 250mm soft Red
BG707116 Stardisc Blue 250mm
BG707117 Stardisc Green 250mm
BG707118 Stardisc Red 250mm
BG707114 Stardisc Black 250mm
E09250
ARROW GRINDING DISC
Ø250 MM
E12020-250PCDG
PCD GRINDING DISC Ø250 MM
(For hard sub-floors)
BG707250-1
PCD GRINDING DISC Ø250 MM
(For soft sub-floors)
005014SR
SUCTION HOSE Ø76 MM
BG707115
BLUE PREMIUM DISC Ø250
E12525
FLOATING SHROUD FOR
BUSHHAMMER TOOLS
E12634
MACHINE SUPPORT LONG
E07463
Cutterplate 250 cpl.with bush
hammers

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3. Safety
Warning!
Read all safety warnings and all instructions. Failure to follow the warnings and
instructions may result in electric shock, fire, explosions and / or serious injuries.
Only authorized and trained personnel may operate this machine. This machine is not intended for use by
persons (including children) with reduced physical, sensory or mental capabilities, or lack of experience and
knowledge.
It is the responsibility of the user to analyse the surface to be treated. The surface may not contain any
substances which could pose a fire-, explosion- or health risk when treated. The user should make a risk
assessment on the basis of the information obtained about the surface to be treated and take proper
precautions for the work to be performed.
In case of any inappropriate usage, improper operation or repair, the producer shall be exempt from liability.
3.1 Work area safety
a) Do not use the machine in rain, damp or wet locations.
b) Avoid dangerous environments: do not work in the presence of explosive atmospheres, in the presence of
flammable liquids, gases or dust. Remove materials or debris that may be ignited by sparks.
c) In some cases sparks could be created by grinding.
d) The surface to be treated must be clean, make sure to remove all stones, screws etc..
Any stones, screws, bolts, pieces of wire etc. could cause serious damage to the machine if it gets inside
the machine!
e) Make sure there is enough ambient light on the work area. Cluttered or dark areas invite accidents.
f) Keep children and bystanders away while operating the machine. They are likely not to foresee the
potential dangers of the machine. Distractions could cause you to lose control of the machine.
g) Persons who are not operating the machine must not be permitted to stay in the surrounding area of at
least 5 meter from the machine.
h) Never use the machine when the surface is not clear and if there is a risk of stumbling or tripping.
i) Remove electrical cables and dust hose(s) from the surface to be treated.
j) Make sure that there are no cables or hoses in the driving direction of the machine.
k) Make sure that there is nothing standing or situated on the surface to be treated.
l) Never stay in the rain with the machine.
m) Check if there are any obstacles that can snag the cables when the machine is moving.
n) Remove all objects from the surface that can damage the machine. Remove reinforcing steel or other
objects protruding from the surface in order to prevent damage to the compounds or diamond discs.
o) Warning! Make sure that the surface to be treated does not contain dangerous materials such
as: - combustible or explosive dusts or substances.
- carcinogenic or pathogenic substances. (Except for the Asbestos version.)
p) It is necessary to provide for an adequate air change rate L in the room if the exhaust air is returned to
the room. Comply with the National regulations.
q) Secure the work area around the machine in public areas providing an adequate safety distance from the
machine. Use a red and white safety chain and danger sign to enclose the work area.
3.2 Electrical safety
a) Use only extension cables for extending the main cable that are sized and marked in accordance with the
overall power consumption of the machine. Do not use damaged extension cables.
b) Electrical cables must be rolled entirely off of the reels.
c) Any damage to the electric cables and/or electrical components is not permitted.
d) The voltage on the identification plate must comply with the power supply.
e) Use an electrical power supply connection with earth connection and earth leakage circuit breaker.
f) The circuit breaker of the power supply must have a ‘’D’’ characteristic. Circuit breakers with a “C” or “B”
characteristic can give problems when switching the machine on.
g) Keep the machine original; The machine is always equipped with an earthed connection, do not
change this and always use earthed cables with an earthed plug.
h) Inspect and test the electrical components regularly. The electrical components have to satisfy with the
requirements set out in the harmonised norm EN60204-1.

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i) Always call a skilled electrician or your distributor when you have questions about the safety of the
electrical components.
j) Work on electrical equipment or operating materials may only be undertaken by a skilled electrician or by
trained persons under the guidance and supervision of a skilled electrician as well as in accordance with
the electrical engineering regulations.
k) Always use tools that are insulated against voltages.
l) Do not abuse the cables. Never use the cables for carrying, pulling or unplugging the machine. Keep
cables away from heat, oil, sharp edges or moving parts. Damaged or entangled cables increase the risk
of electric shock. Do not fold the cable or clamp it.
m) Don’t pull out the power supply cable out by the wire, but by the connector.
n) Be careful with water on the treated surface. Electrical cables must not come into contact with water.
o) The main power switch on the machine must be in the “Off” position before connecting to the power
supply.
p) During a long standstill of the machine, pull out the main plug.
q) If the machine is to be operated using power from a generator, the generator must be operated in
accordance with the current legal regulations and directives in force. (this applies to the protective earth
conductor in particular) in order to ensure that all safety devices are functioning and to eliminate possible
damage to electrical components.
3.3 Personal safety
a) Always wear Personal Protective Equipment while working with the machine.
-Dust mask class FFP3 or higher
-Ear protection
-Safety glasses with lateral protection
-Protecting gloves
-Safety shoes
b) Dress properly. Do not wear loose clothing or jewellery. Keep your hair, clothing and gloves away from
moving parts.
c) Personnel must tie back long hair and not wear loose clothing or jewellery including rings.
d) Stay alert, watch what you are doing and use common sense when operating the machine.
e) The cord of the deadman switch key should always be fastened on your arm or on to your clothing.
f) Pull out the key of the deadman switch before any inspections, adjustments and/or maintenance work is
started.
g) Always seek professional medical attention immediately in case of injury.
h) All persons surrounding the machine should wear Personal Protective Equipment.
3.4 Machine safety general
a) Safety functions and operating functions must work correct.
b) No loose bolts and nuts permitted.
c) Never operate machine without the guards and/or safety devices in place.
d) Never change anything on the safety devices on the machine!
e) Do not use the machine when it is damaged.
f) Do not open or remove protective guards while driving gears are running.
g) The machine, specially the handle grips must be dry and free of fats/oils.
h) If the length of the brushes is, due to wear, less than 5mm or they are extremely deformed, the brushes
have to be replaced. Check the Service Manual for the order numbers.
i) All repair work has to be done by qualified Blastrac personnel, this guarantees a safe and reliable
machine.
j) Always use original Blastrac spare parts, grinding disks and polishing pads. This will ensure the
best performance.
Only original parts meet the factory specifications and quality. Otherwise Blastrac BV cannot guarantee
the safety of the machine.
The part numbers can be found in the Service Manual.
k) Check the rotating direction of the motor before operation. The correct direction is given with an arrow on
the housing of the motor.
l) If safety-critical changes occur to the machine or its working method, the machine must be shut down
immediately! The cause of the fault must be established, and rectified.
m) In the event of operational malfunctions the machine must be shut down immediately and secured!
n) Never use the machine without a suitable (Blastrac) dust collector!

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3.5 Grinding safety
a) The machine contains rotating parts, which are protected with a cover. Always leave the diamond disc on
the floor while the motor is turning.
b) The flexible coupling can become worn out with use, because of this there can be higher vibrations than
normal. Check for this reason the flexible coupling for deformation and damage before every use.
c) Do not let the machine rest on the diamond disc or coupling when it is not in use, this will cause
deformation to the flexible coupling.
d) Always put the machine on the machine support which is made especially for this reason.
e) Make sure the brush seals are in good condition, this to avoid dust escaping.
f) Make sure the diamond disc is not damaged or worn out.
g) Always pull out the main plug before u start changing the grinding disks or polishing pads.
h) When mounting or removing a diamond disc; lay down the machine so it is lying on the handle. Make sure
the machine will not fall back down. A second person can hold the handle down, to make sure it will not
fall back down.
i) When changing the disks u should wear Personal Protective Equipment like a dust mask, safety goggles,
gloves, protective shoes, and close fitting protective clothing.
Use the vacuum cleaner while changing the discs to prevent excessive dust.
j) Caution! The grinding disc will heat up during grinding, don’t risk getting burned, always wear
protective gloves when handling them!
k) The machine contains rotating parts; because of this never pull the machine backwards with a turning
motor.
l) Be careful with the machine and pull or let down the machine slowly, big shocks can damage the electrical
parts.
3.6 Dustcollector safety
a) Always use a Blastrac dust collector to ensure a dust-free operation of the machine and clean air at the
workspace. Also the airflow helps to cool the machine and prevents overheating.
b) When working on or around carcinogenic or pathogenic substances, the dust collector must be fitted
with a HEPA filter.
c) Read the operating instructions of the dust collector before using it.
d) The dust container/bag of the dust collector must be emptied regularly. Comply with the local waste
treatment regulations considering the removed material.
e) The dust hose must be connected properly with a hose clamp and industrial tape.
f) The dust hose must be undamaged and free of obstructions.
g) Always switch on the dust collector first!
3.7 Petrol version safety
a) Make sure there is no oil or petrol leaking out of the petrol engine.
b) Always make a pre-operation inspection before you start the engine. You may prevent an accident or
equipment damage.
c) Look for signs of damage and remove any excessive dirt or debris.
d) To prevent fire hazards and to provide adequate ventilation, keep the engine at least 1 meter
(3 feet) away from buildings and other equipment during operation.
Do not place flammable objects close to the engine.
e) Anyone who is not operating this machine must be kept away from the area of operation due to a
possibility of burns from hot engine components. Parts will remain hot for a while after stopping the
engine. Let the engine cool before transporting it or storing it indoors.
f) When transporting or storing the engine, turn the fuel valve OFF and keep the engine horizontal.
g) Know how to stop the engine quickly, and understand the operation of all controls. Never permit anyone
to operate the engine without proper instructions.
h) Do not place flammable objects such as gasoline, matches, etc., close to the engine while it is running. Do
not place anything on the engine.
i) Refuel in a well-ventilated area with the engine stopped. Gasoline is highly flammable and explosive under
certain conditions. Let engine cool before refueling.
j) Do not overfill the fuel tank. There should be no fuel in the filler neck.
k) Do not smoke or allow flames or sparks where the engine is refueled or where gasoline is stored.
l) ! Exhaust gas contains poisonous carbon monoxide. Avoid inhalation of exhaust gases. Never run
the engine in a closed garage or confined area! Always wear a dust mask.

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Breathing carbon monoxide can cause unconsciousness or death.
m) If any fuel is spilled, clean it up completely and allow petroleum vapours to dissipate before starting the
engine.
n) Make sure the fuel and oil level are correct and that the filler cap is closed securely.
o) Don’t leave the machine laying backwards for a long time, because this may result in fuel spillage.
READ THE OPERATING INSTRUCTIONS OF THE PETROL MOTOR BEFORE USING IT!
3.8 Battery safety (12V)
a) Only use Blastrac approved batteries. Blastrac cannot guarantee the safety of the machine when other
batteries are used.
b) Every service work on batteries should only be done by trained personnel.
c) The battery contains lead-acid, do not disassemble, heat above 60°C, or incinerate.
d) Immediately flush eyes with cold, fresh water for a minimum of 15 minutes if electrolytic acid comes in
contact with eyes. Seek professional medical attention immediately.
e) For work with the battery you need to remove all metal jewelry like rings, watches, necklaces etc. They
can be a cause of serious burns.
f) The old battery should be recycled. Batteries contain harmful materials, like lead en sulphuric acid. These
materials form an environmental and health hazard. Therefore it is imperative that they are recycled
responsibly in accordance with local disposal and environmental regulations.
3.9 Asbestos safety
a) Always check and comply with the local authorities and regulations!
b) Employees that are responsible for the execution of the asbestos removal must be trained and certified
accordingly.
c) Operators and other third parties that are involved in asbestos removal and in that context are present in
the work area must have sufficient knowledge of the risks with respect to asbestos.
d) Such persons must (according to the labour regulations) proven to be instructed (information and
education) about the health risks of working with (or at) asbestos (removal) and the measures for
personal protection with regard to possible exposure to asbestos.
e) The operator must know the usual procedures when leaving the working area, including the visual
inspection en cleaning of the machine being used.
f) The operator must use respiratory protection which is sufficient for work with asbestos, and must have
knowledge of the correct HEPA filters that are to be used.
g) If there is a possibility that asbestos fibres are released, they shall be collected at the exit or point of
origin and then be disposed of without risk to human and environment according to the local regulations.
h) If it is not possible to completely collect the contaminants, additional ventilation and filtration measures
must be taken.
i) At the end of work the complete machine including the dust collector, tools, work equipment and the work
area must be carefully cleaned according to local regulations.
j) Objects contaminated with asbestos fibres that cannot be cleaned must be moistened and eliminated
properly. After cleaning the work area must be adequately ventilated.
k) Extracted air must be guided and cleaned so that asbestos fibres are not released into the breathing air of
other employees.
l) The dust produced and collected must be transported in dustproof containers. Decanting is not permitted.
m) The extracted air which is released back into the outside air may not exceed a fibre content of 1000 F/m³.
n) The dust collector must be a type-approved industrial vacuum cleaner or dust collector with HEPA filter
and meet this criterion.
o) It must be ensured that the working area is supplied with sufficient outdoor air (fresh air).
p) For activities involving materials containing asbestos, a recirculation of purified air in the work area are
not allowed. The following activities with the industrial vacuum cleaner or dust collector recirculation of
purified air are permitted: 1: Activities involving low exposure according to TRGS 519, Number 2.8
confined spaces or small-scale work to TRGS 519, Section 2.10, and 2: cleaning.
q) the outside of the machine should be decontaminated by cleaning and vacuuming methods, de-dusted
before being taken out from the hazardous zone. All parts of the machine must be considered as
contaminated when they are removed from the hazardous zone and appropriate actions must be taken to
prevent dust from dispersing.
r) The machine is to be serviced and cleaned, as often as is required, but at least once a year, and if
necessary, repaired by a competent person (see qualification TRGS 519, Number 5.3, paragraph 2) and
checked by a maintenance company. The test result must be provided on request.

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s) The machine and dust collector used in the black area may only operate in the white area after complete
cleaning, including the motor housing. For engines with bypass cooling the cooling air ducts have to be
clean.
t) When maintenance or repair procedures are carried out, all the contaminated elements that cannot be
properly cleaned, must be destroyed.
u) These elements must be disposed of in sealed bags according to the applicable regulations and in
accordance with the local laws governing the disposal of such material. This procedure must also be
followed when the filter has to be disposed.
3.10 Maintenance safety
a) Pull out the main plug and place it in sight, before starting inspections and repairing on the machine. Take
the key of the dead man switch out of the machine.
b) Wait for standstill of all drives before any inspections, adjustments and/or maintenance work is started.
c) Block machine in stable position before doing any maintenance work.
d) Failures due to inadequate or incorrect maintenance may generate very high repair costs and long
standstill periods of the machine. Regular maintenance therefore is imperative.
e) Operational safety and service life of the machine depends, among other things, on proper maintenance.
f) Prevent premature wear by keeping the machine as dust free as possible. Clean the machine for this
reason regularly with a dust collector and non-aggressive materials. Never use a high pressure water
cleaner to clean the machine.
g) Do not use any aggressive cleaning materials!
h) Use lint-free cleaning cloths!
i) It is advisable to stock all spare parts or wear parts that cannot be supplied quickly. As a rule, production
standstill periods are more expensive than the cost for the corresponding spare part.
j) To allow the user to carry out maintenance operations, the machine must be disassembled, cleaned and
inspected as far as reasonably possible, without causing hazards for the maintenance staff or other
people.
k) The suitable precautions include decontamination before disassembling the machine, adequate filtered
ventilation of the exhaust air from the room in which it is disassembled, cleaning of the maintenance area
and suitable personal protection equipment.
3.11 Transport safety
a) Be aware of your surroundings and machine operating level. Do not side hill, do not run on steep incline,
this could cause machine to tip over.
b) The net weight of the BG-250 is 146 kg. Use a crane or lift when transporting the machine, use the lifting
eye of the machine.
c) Before every use check the lifting eye and welds for:
deformation, damages, cracks, corrosion and wear.
d) Hold on to the steering handle until the machine is of the ground.
e) When lifting the machine from the ground, always use the lowest lifting speed. The cables must first be
tensioned at this speed; they must not be slack when the machine is lifted from the ground.
f) During hoisting make sure to be at a safe distance from the machine with the most optimal view on the
machine and working environment.
g) Never stand directly below the machine.
h) When transporting the machine do so in such a manner that damage due to the effects of the use of force
or incorrect loading and unloading is avoided.
i) The lifting eye can also be used to fasten the machine on a pallet or during transport.
j) Always drive backwards when driving up to a ramp or grade, and forwards when driving of the ramp.
m) Chock wheels for transport and always put the machine on the machine support which is made especially
for this reason.
n) Do not let the machine rest on the diamond disc or coupling when it is not in use, this will cause
deformation to the flexible coupling.
k) Don’t leave the machine unsecured on jobsites.
l) Park the machine always on a flat horizontal and levelled surface.
m) Make sure the electrical cable and dust hose are disconnected before transport.
n) Store the cleaned and dry machine in a humid free room. Protect the electrical motor from moisture, heat
dust and shocks.
o) Never use the machine for lifting persons or items.

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p) Only lift the machine as shown in the picture below.

13
3.12 Signs on the machine
The following stickers are placed on the machine. Meanings of these symbols are:
Type plate:
EU Declaration of Conformity:
Wear a dust mask class FFP2 or
higher.
Hearing protection is obliged.
Safety glasses with lateral protection
are obliged.
CE-mark on this machine.
Wear protecting gloves.
Safety shoes obliged.
Consult the manual before operating
the machine.
Name, address and CE mark.
The machine type.
The net weight of the machine in kilogram.
The year of manufacture.
The serial number of the machine.
Email address, Website, Telephone & fax number.
! Danger Hazardous voltage in motor
even when solid state controller is OFF.
Disconnect main power before servicing
motor, controller or associated wiring.
Warning! Hot surface.

14
4. Initial operation
Before using the machine it is essential to inspect the machine.
It is not permitted to use the machine if the machine safety is not according the checkpoints below.
Before switching on the machine make sure that no-one can be endangered when the machine starts up!
4.1 Checkpoints power supply
Use only extension cables for extending the main cable that are sized and marked in accordance with
the overall power consumption of the machine.
Electrical cables must be fully unwind of them reels.
No damage is permitted for electrical cables.
Use an electrical power supply connection with earth connecting.
Make sure the power supply is in accordance with the machine specifications.
The circuit breaker of the power supply must have a ‘’D’’ characteristic. Circuit breakers with a “C” or
“B” characteristic can give problems when switching the machine on.
If the machine is to be operated using power from a generator, the generator must be operated in
accordance with the current legal regulations and directives in force. (this applies to the protective
earth conductor in particular) in order to ensure that all safety devices are functioning and to eliminate
possible damage to electrical components.
4.2 Checkpoints of machine
Safety functions and operating functions must work correct.
Check all screws and other fasteners for tightness. No loose bolts and/or nuts are permitted.
Check the electrical components, cables and connections for wear and/or damages.
Dust hose connections must be reliable: use hose clamps and industrial tape.
Dust hoses must be undamaged and free of obstructions.
Make sure that the dust bin / bigbag of the dust collector is empty and connected properly.
The flexible coupling is not deformed or damaged.
The diamond disc is not damaged.
There is no oil or petrol leaking out of the petrol engine.
4.3 Checkpoints of work area
Before grinding, clean the surface to be treated. There should not be any trash, stones, cloths, or oil
on the surface.
Remove all objects from the surface that can damage the machine. Remove reinforcing steel or other
objects protruding from the surface in order to prevent damage to the machine, the seals or diamond
disc.
When working with the petrol version, make sure there is enough ventilation in the work area!
When working with the Asbestos version, check and comply with the local regulations!
4.4 Manual moving of the machine
To move the machine press down the handgrips of the machine until the front part rises from the
ground. It can now be pushed around on its wheels.
The machine should only be moved around when the dust hose and power supply cable are
disconnected.
Be careful! Make sure nobodies feet get under the wheels. Wear appropriate safety shoes when you
drive the machine to or from the work area.
WARNING! Always make sure all rotating parts have come to a complete standstill before moving around the
machine.

15
4.5 Changing the diamond disc
Read chapter 3 “Safety” before changing the disk.
Warning! Always wear Personal Protective Equipment!
The dust can be hazardous to the health! Wear a dustmask!
The disk can get hot! Don’t risk burning your hands! Wear protective gloves!
Removing the diamond disc
Read chapter 3 Safety.
Make sure the machine cannot start up. Remove the key of the deadman switch and unplug the power
supply plug (on electrical versions) Remove the ignition key from the contact switch (Petrol version).
Lay down the machine so it is lying on the handle. Make sure the machine will not fall back down. A
second person can hold the handle down, to make sure it will not fall back down.
Loosen the 4 bolts with an appropriate key.
Remove the diamond or multiflail disc.
Mounting the diamond disc
Read chapter 3 Safety.
Make sure the machine cannot start up. Remove the key of the deadman switch and unplug the power
supply plug (on electrical versions) Remove the ignition key from the contact switch (Petrol version).
Lay down the machine so it is lying on the handle. Make sure the machine will not fall back down. A
second person can hold the handle down, to make sure it will not fall back down.
Fix the diamond or multiflail disc underneath the adapter plate and turn the 4 bolts with an appropriate
key tight.
Pull out the mains plug before you start
Always wear gloves and a dust mask of at least class FFP3
Use an extra vacuum cleaner in order to work as dust free as possible

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5. Operating
During operating the machine, the following additional safety instructions must be followed closely.
Before switching on the machine make sure that no-one can be endangered when the machine starts up.
Make sure that no vehicles, such as forklift trucks and other equipment run over the electric cable and the dust
hose.
5.1 Before switch on
Checking the turning direction of the motor
Make sure the machine is on its machine support and start the machine for a few seconds by pressing
the START-button.
Stop the machine by pressing the red STOP-button.
Check the rotating direction of the motor (the correct direction is indicated with an arrow).
The fan has to turn clockwise when looking on top of the fan.
Correcting the turning direction of the motor
Switch off the motor.
Wait for a complete standstill of all drives.
Unplug the machine from the power supply.
Rotate the inverter switch inside the mains plug to the opposite position.
Reconnect the machine to the power supply and check the turning direction of the motor again.
5.2 Switch on the BG-250E
Turn on the dust collector before switching on the machine.
Connect the dust hose between the dust collector and the machine.
Stand behind the machine.
Make sure that the machine stands on the machine support.
Put the cord of the deadman switch (1) on to your arm or put it on to your clothing.
Check if the key of the deadman switch (1) is in and the stop button (4) is turned up.
Take the steering handle (2) with one hand and push the start button (3).
Check if the machine turns the right direction.
Lift the machine support with the lever handle (6) and let down the machine till the diamond disc hits
the floor.
Start grinding.
5.3 Switch off the BG-250E
Push the red button (4) on the electrical box
Wait until the machine stops rotating before you
set the machine on the support with the lever
handle (6)
Pull out the power supply and the key of the
deadman switch (1)
Shut down the dust collector.

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5.4 Switch on the BG-250P
Turn on the dust collector before switching on the
machine.
Connect the dust hose with the machine
Open the fuel valve (1)
Stand behind the machine
Make sure that the machine stands on the machine
support.
Put the cord of the deadman switch (2) on to your arm or
put it on to your clothing.
Check if the key of the deadman switch (2) is in and the
stop button (6) is turned up.
Take the steering handle (3) with one hand pull the gas
throttle (4) up to the half and turn the contact switch (5)
to start the engine.
When the battery is empty, the machine could always be
started with the cord (7)
Lift the machine support with the lever handle (8) and let
down the machine till the diamond disc hits the floor
Start grinding and pull the gas throttle (4) for more
grinding speed.
5.5 Switch off the BG-250P
Push the gas throttle (4) to the front.
Push the red button (6)
Wait until the machine stops rotating before you set the machine on the support with the lever handle
(8)
Pull out the power supply and the key of the deadman switch (2)
Close the fuel valve (1)
Shut down the dust collector.

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5.6 Asbestos version
The BG-250A (asbestos version) can be used to remove
carcinogenic or pathogenic substances which are dangerous
for health, for example asbestos.
To ensure the safety of the operator, the BG-250A has an extra
safety mechanism. The differential pressure switch which monitors
the suction power of the dust collector.
Safety functions:
1. The grinding machine can only be operated when a dust
collector with sufficient suction power is connected and
turned on.
2. If the connected dust collector does not have enough
suction power or it is turned off, the grinding machine will
not turn on.
3. If the connected dust collector loses its suction power or it
is turned off during grinding, the grinding machine will
turn off automatically. (To ensure that there is no release
of asbestos fibres into the air.)
The machine may only be used with asbestos when a dust collector
with HEPA filter is properly connected.
The differential pressure switch is an adjustable gas-differential pressure
switch as per EN 1854. The reference value (switching point) is adjusted
on a setting wheel provided with a scale inside the box.
The differential pressure switch is set at -10mbar.
The differential pressure acts on the membrane, pressing it against the force of the adjusting spring and
against the microswitch. The pressure switch operates without outside power. The switching apparatus reacts
to the difference in pressure between the two pressure chambers and, if the pressure drops below the
setpoint, switches the electrical circuit off. The pressure difference is measured inside the dust hose connection
and on the side of the box. The measuring points may not be closed.
The differential pressure switch is protected with a filter, never use the machine without the filter in place.
The filter has to be replaced at least once a year, by a competent person.
Always check if the differential pressure switch works correct before grinding work starts:
1. Make sure the machine stands on its machine support.
2. Connect the machine with a dusthose to the dust collector.The dust hose must be
undamaged and free of obstructions. It must be connected properly with hose clamps and
industrial tape.
3. Turn on the dust collector, the green control light on the grinding machine will light up.
4. Turn the grinding machine on. (See chapter “Troubleshooting” if the machine won’t start)
5. Turn the dust collector off, the grinding machine should automatically turn off. If the
grinding machine does not turn off automatically, the filter and air hoses should be
checked for clogging and the differential pressure switch should be checked for the correct
setting.
Clean the pressure switch with a damp cloth only. Work on the pressure switch may only be performed by
specialist staff. Do not allow condensate to flow into the equipment. In case of sub-zero temperatures,
malfunction or equipment failure may be possible due to icing. Avoid silicone oils and volatile silicones
(siloxanes) in the environment, malfunction / failure possible. If these instructions are not heeded, the result
may be personal injury or damage to property.
Differential pressure switch

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5.7 Operation with bushhammer tools
The BG-250E can be used with bushhammer tools, however, in the normal configuration the RPM’s of the BG-
250E are too high for bushhammering. To reduce the RPM’s, the pulley of the grinding motor and the pulley of
the bearing unit have to be exchanged. (This only for normal electric machines. The petrol machines can
adjust the RPM’s with the gas throttle. The BG-250TWIN has the switch for “LOW” RPM’s)
Changing the pulleys:
-Remove the front cover
-Loosen 4x M14 nuts to loosen the grinding motor
-Release the belt tension by loosening the M10 locking nut and remove the v-belt
-Remove the pulleys from the grinding motor and bearing unit
The pulley & taperlock must be mounted evenly with the motor-axle (as shown in picture 1):
2. The pulley & taperlock on the bearingunit must be lined out
from the motor pulley to the bearingunit pulley (use an aligning
ruler).
Tighten the taperlocks on 20NM + 10%.
1.
Release belt tension here

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Change the wheels to the lowest hole in the frame.
See pictures.
(Changing the wheel height has to be done on all BG-250 models)
Mounting the E12525 - BG-250 floating shroud for bush hammer tools:
1x E12525 BG-250 floating shroud for bush hammer tools
4x BE0655 M6 8x12 Hexagon socked head shoulder bolt 12.9
4x BE0016 M6 Plain washer
4x BE0158 M6 Lock nut
Mounting the E12634 –Machine support LONG:
Grinding
Bushhammers
When working with bushhammers, the normal machine support cannot be used.
Remove the normal machine support and mount the Machine support LONG.
Never let the machine rest on the bushhammers! This will deform your flexible
coupling! Always use the machine support when the machine is not in use!