For Your Safety; Dust/Chip Extraction - Bosch Professional GAC 250 Original Instructions Manual

12 | English
AAC Block cutter
Stop
Weight according to EPTA-
Procedure 01:2014
Protection class
The specifications apply to a rated voltage [U] of 230 V. These spe-
cifications may vary at different voltages and in country-specific mod-
els.
Starting cycles generate brief voltage drops. Interference with other
equipment/machines may occur in case of unfavourable mains sys-
tem conditions. Malfunctions are not to be expected for system im-
pedances below 0.25 ohm.
Values can vary depending upon the product and are subject to ap-
plication and environmental conditions. For further information
www.bosch-professional.com/wac.
Assembly

For Your Safety

Warning! Switch off, remove plug from mains before
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adjusting or cleaning. The same applies when the
mains cable is damaged, cut or entangled.
Caution! Do not touch the rotating chain.
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Never operate the power tool in the vicinity of per-
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sons, children or animals or after consuming alcohol,
drugs or taking numbing medication.
Mounting and Tensioning the Saw Chain
Only connect the power tool to the mains supply once
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it has been fully assembled.
Always wear protective gloves when handling the
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chain.
Assembling the Chain Bar and Saw Chain (see figures A–
C)
– Carefully unpack all of the parts.
– Set down the power tool on a level surface.
– Insert the saw chain (8) into the circumferential groove of
the chain bar (9). Ensure that the running direction is cor-
rect. To do this, compare the saw chain against the run-
ning direction symbol (16).
– Make sure that the tension wheel (13) is in the – position.
– Put the chain links around the sprocket wheel (17) and
position the chain bar (9) on the fastening bolt (18).
Note: During initial assembly, the bolt (21) must engage
in the mounting hole on the chain bar (9) that is furthest
away from the sprocket wheel (17) (see figure A).
– Check whether all of the parts are positioned correctly
and hold the chain bar with the saw chain in this position.
Then turn the tension wheel (13) in the + direction until
the saw chain is partially tensioned and remains mounted
on the chain bar.
– Replace the cover (12).
– Tighten the cover (12) slightly with the knob (11).
1 609 92A 8GB | (03.04.2023)
– The saw chain is not yet fully tensioned. The saw chain is
GAC 250
●
kg 4.7
Tensioning the Saw Chain (see figure D)
Check the chain tension regularly every ten minutes, includ-
/ II
ing before starting work, after the initial steps and during
sawing. Particularly when using new saw chains, increased
extension should be expected initially.
The service life of the saw chain relies heavily on it being ten-
sioned correctly.
Do not tension the saw chain if it is strongly heated because
it will tighten once it has cooled down and it will fit too tightly
on the chain bar.
– Set down the power tool on a level surface.
– Turn the knob (11) in the
– Check whether the chain links are correctly positioned in
– Turn the tension wheel (13) in the + direction until the
– The saw chain (8) is tensioned correctly if it can be lifted
– If the saw chain (8) is tensioned excessively, turn the ten-
– When the saw chain (8) is tensioned, secure the chain

Dust/chip extraction

Dust from materials can be harmful to health. Touching or
breathing in this dust can trigger allergic reactions and/or
cause respiratory illnesses in the user or in people in the
near vicinity.
Certain dusts are classified as carcinogenic.
– Use a dust extraction system that is suitable for the ma-
– Provide good ventilation at the workplace.
– It is advisable to wear a P2 filter class breathing mask.
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External Dust Extraction (see figure I)
Insert the extraction hose (20) with adapter into the extrac-
tion outlet (15). Connect the dust extraction hose to a dust
extractor (accessory). You will find an overview of how to
connect to various dust extractors at the end of these oper-
ating instructions.
tensioned as described in the "Tensioning the Saw Chain"
section.
direction in order to release
the fixed chain bar.
the guide slot of the chain bar (9) and on the sprocket
wheel (17).
correct chain tension has been reached. The latching
mechanism stops the chain tension from being released.
If the tension wheel (13) is hard to turn, you must con-
tinue to loosen the knob (11) in the
knob (11) can also rotate if the tension wheel (13) is set.
Two hands may be required to hold the knob (11) in posi-
tion while setting the tension wheel (13).
in the middle by approx. 3–4 mm. This should be done
with one hand by pulling up the saw chain against the
power tool's own weight.
sion wheel (13) in the – direction.
bar (9) by turning the knob (11) in the
not use a tool to do this.
terial wherever possible.
Avoid dust accumulation at the workplace. Dust can
easily ignite.
direction. The
direction. Do
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