Ryobi MMA-140 Owner's Operating Manual page 11

5. The health of people around, e.g. the use of
pacemakers and hearing aids.
6. Equipment used for calibration and
measurement.
7. The time of day that welding or other activities
are to be carried out.
8. The immunity of other equipment in the
environment: the user shall ensure that other
equipment being used in the environment is
compatible: this may require additional
protection measures.
The size of the surrounding area to be considered
will depend on the structure of the building and
other activities that are taking place. The surround-
ing area may extend beyond the boundaries of the
premises.
C. Methods of Reducing Electromagnetic
Emissions
1. Mains Supply
Welding equipment should be connected to
the mains supply according to the
manufacturer's recommendations. If
interference occurs, it may be necessary to
take additional precautions such as filtering
of the mains supply. Consideration should be
given to shielding the supply cable of
permanently installed welding equipment in
metallic conduit or equivalent. Shielding should
be electrically continuous throughout it's
length. The shielding should be connected to
the Welding Power Source so that good
electrical contact is maintained between the
conduit and the Welding Power Source
enclosure.
2. Maintenance of Welding Equipment
The welding equipment should be routinely
maintained according to the manufacturer's
recommendations. All access and service
doors and covers should be closed and
properly fastened when the welding equipment
is in operation.
The welding equipment should not be modified
in any way except for those changes and
adjustments covered in the manufacturer's
instructions. In particular, the spark gaps of arc
striking and stabilising devices should be
adjusted and maintained according to the
manufacturer's recommendations.
ELECTROMAGNETIC COMPATIBILITY
3. Welding Cables
The welding cables should be kept as short as
possible and should be positioned close
together, running at or close to the floor level.
4. Equipotential Bonding
Bonding of all metallic components in the
welding installation and adjacent to it should be
considered. However. Metallic components
bonded to the work piece will increase the risk
that the operator could receive a shock by
touching the metallic components and the
electrode at the same time. The operator
should be insulated from all such bonded
metallic components.
5. Earthing of the Workpiece
Where the workpiece is not bonded to earth for
electrical safety, nor connected to earth
because of it's size and position, e.g. ship's
hull or building steelwork, a connection
bonding the workpiece to earth may reduce
emissions in some, but not all instances. Care
should be taken to prevent the earthing of the
workpiece increasing the risk of injury to users,
or damage to other electrical equipment.
Where necessary, the connection of the work
piece to earth should be made by direct
connection to the workpiece, but in some
countries where direct connection is not
permitted, the bonding should be achieved by
suitable capacitance, selected according to
national regulations.
6. Screening and Shielding
Selective screening and shielding of other
cables and equipment in the surrounding area
may alleviate problems of interference.
Screening the entire welding installation may
be considered for special applications.
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