·１１·
Appendix A
1. General
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 remedial action may be as simple as earthling the
welding circuit, see note. In other cases it could involve constructing an electromagnetic screen
enclosing the welding power source and the word complete with associated input filters. In all cases
electromagnetic disturbances shall be reduced to the point, where they are no longer troublesome.
NOTE: The welding circuit may not be earthed for safety reasons. Changing the earthling
arrangements should only be authorized by a person who is competent to assess whether the
changes will increase the risk of injury.
2. Assessment of area
Before installing arc welding equipment the user shall make an assessment of potential electromagnetic
problems in the surrounding area. The following shall be taken into account:
1) Other supply cables, control cables, signaling and telephone cables, above, below and adjacent to the
arc welding equipment;
2) Radio and television transmitters and receivers;
3) Computer and other control equipment;
4) Safety critical equipment, for example guarding of industrial equipment;
5) The health of the people around, for example the use of pacemakers and hearing aids;
6) Equipment used for calibration or measurement;
7) The immunity of other equipment in the environment is compatible. The user shall ensure that other
equipment being used in the environment is compatible. This may require additional protection
measures;
8) The time of day that welding or other activities are to be carried out.
3. Methods of reducing emissions
1) Public supply system
Arc welding equipment should be connected to the public supply system according to the
manufacturer’s recommendations. If interference occurs, it may be necessary to take additional
precautions such as filtering of the public 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 its length. The shielding should be connected to the
