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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 its 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.
2.2 Maintenance of the welding equipment
The welding equipment should be routinely maintained according to the
manufacturers 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 manufacturers instructions. In particular,
the spark gaps of arc striking and stabilizing devices should be adjusted and
maintained according to the manufacturers recommendations.
2.3 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.
2.4 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 these
metallic components and the electrodes at the same time. The operator should
be insulated from all such bonded metallic components.
2.5 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, e.g. ships 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 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
capacitance, selected according to national regulations.
2.6 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 welding
installation may be considered for special applications.
