SC-12 Safety and Compliance
Electromagnetic Compatibility (EMC)
Maintenance of cutting equipment
The cutting equipment must be routinely maintained
according to the manufacturer’s recommendations. All
access and service doors and covers should be closed
and properly fastened when the cutting equipment is in
operation. The cutting equipment should not be modified
in any way, except as set forth in and in accordance with
the manufacturer’s written instructions. For example, the
spark gaps of arc striking and stabilizing devices should
be adjusted and maintained according to the
manufacturer’s recommendations.
Cutting cables
The cutting cables should be kept as short as possible
and should be positioned close together, running at or
close to the floor level.
Equipotential bonding
Bonding of all metallic components in the cutting
installation and adjacent to it should be considered.
However, metallic components bonded to the workpiece
will increase the risk that the operator could receive a
shock by touching these metallic components and the
electrode (nozzle for laser heads) at the same time.
The operator should be insulated from all such bonded
metallic components.
Earthing of the workpiece
Where the workpiece is not bonded to earth for electrical
safety, nor connected to earth because of its size and
position, for example, ship’s hull or building steel work, 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
workpiece to earth should be made by a direct connection
to the workpiece, but in some countries where direct
connection is not permitted, the bonding should be
achieved by suitable capacitances selected according to
national regulations.
Note: The cutting circuit may or may not be earthed for
safety reasons. Changing the earthing arrangements
should only be authorized by a person who is competent
to assess whether the changes will in crease the risk of
injury, for example, by allowing parallel cutting current
return paths which may damage the earth circuits of other
equipment. Further guidance is provided in IEC 60974-9,
Arc Welding Equipment, Part 9: Installation and Use.
Screening and shielding
Selective screening and shielding of other cables and
equipment in the surrounding area may alleviate problems
of interference. Screening of the entire plasma cutting
installation may be considered for special applications.
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