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1.1 ELECTROMAGNETIC COMPATIBILITY
The user is responsible for installing and using the arc welding equipment according to the manufacturer’s instructions. If
electromagnetic disturbances are detected, then it shall be the responsibility of the user of the arc welding equipment to
resolve the situation with the technical assistance of the manufacturer. In some cases, this action may be as simple as
connecting to earth the welding circuit. In other cases, it could involve constructing electromagnetic screens enclosing the
welding power source and the work complete with associated input filters. In all cases, electromagnetic disturbances shall
be reduced to the minimum to avoid troubles.
Before installing arc welding equipment, the user shall assess potential electromagnetic problems in the surrounding area.
The following shall be considered:
a) Supply cables, control cables, signalling and telephone cables, above, below and adjacent to the arc welding equipment;
b) Radio and television transmitters and receivers;
c) Computer and other control equipment;
d) Safety critical equipment, e.g. guarding of industrial equipment;
e) The health of the people around, e.g. the use of pacemakers and hearing aids;
f) Equipment used for calibration or measurement;
g) 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;
h) The hour of day when welding or other activities are to be carried out.
1.1.1 Methods of reducing emissions
Connection to mains
Arc welding equipment should be connected to the input supply system according to the manufacturer’s recommendations.
If interference occurs, it may be necessary to take additional precautions such as filtering of the supply system.
Consideration should be given to shielding the supply cable of permanently installed arc 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.
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.
Equipotent 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 an electric shock by touching
these metallic components and the electrode at the same time. The operator should be insulated from all such bonded
metallic components.
Connexion to earth of the work piece
When the work piece 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 work piece to earth may reduce emissions in some, but not
all instances. Care should be taken to prevent the earthling of the work piece 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 a
direct connection to the work piece, but in some countries where direct connection is not permitted, the bonding should be
achieved by suitable capacitance, selected according to national regulations.
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.
