SAFETY
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INSTRUCTIONS FOR ELECTRO-
MAGNETIC COMPATIBILITY
Conformance
Products displaying the C-Tick mark are in conformity with
Australian/New Zealand requirements for Electromagnetic
Compatibility (EMC) according to standard (emission) AS/NZS
3652 "Electromagnetic Compatibility – Arc Welding
Equipment".
Products displaying the CE mark are in conformity with
European Community Council Directive 89/336/EEC require-
ments for EMC by implementing EN50199 "Electromagnetic
Compatibility (EMC) – Product standard for arc welding equip-
ment".
Products are:
• For use with other Lincoln Electric/LiquidArc equipment.
• Designed for industrial and professional use.
Introduction
All electrical equipment generates small amounts of electromagnet-
ic emission. Electrical emission may be transmitted through power
lines or radiated through space, similar to a radio transmitter. When
emissions are received by other equipment, electrical interference
may result. Electrical emissions may effect many kinds of electrical
equipment: other nearby welding equipment, radio and TV trans-
mitters and receivers, numerical controlled machines, telephone
systems, computers, etc. Be aware that interference may result
and extra precautions may be required when a welding power
source is used in a domestic establishment.
Installation and Use
The purchaser/user is responsible for installing and using the weld-
ing equipment according to the manufacturer’s instructions. If elec-
tromagnetic disturbances are detected then it shall be the responsi-
bility of the purchaser/user of the welding equipment to resolve the
situation with the technical assistance of the manufacturer. In some
cases this remedial action may be as simple as earthing (ground-
ing) the welding circuit (see note below). In other cases it could
involve constructing an electromagnetic screen enclosing the
power source and the work complete with associated input filters.
In all cases electromagnetic disturbances must be reduced to the
point where they are no longer troublesome.
Note:
The welding circuit may or may not be earthed for safety rea-
sons according to national codes. Changing the earthing arrange-
ments should only be authorized by a person who is competent to
assess whether the changes increase the risk of injury, eg. by
allowing parallel welding current return paths which may damage
the earth circuits of other equipment.
Assessment of Area
Before installing welding equipment the purchaser/user shall make
an assessment of potential problems in the surrounding area.
The following shall be taken into account:
• Other supply cables, control cables, signalling and telephone
cables above, below and adjacent to the welding equipment;
• Radio and television transmitters and receivers;
• Computer and other control equipment;
• Safety critical safety equipment, eg. guarding of industrial
equipment;
• The health of people around, eg. the use of pacemakers and
hearing aids;
• Equipment used for calibration or measurement;
• The immunity of other equipment in the environment. The
purchaser/user shall ensure that other equipment being used
in the environment is compatible. This may require additional
protection measures;
• The time of the day that welding or other activities are to be
carried out.
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 surrounding area may extend beyond the boundaries of
the premises.
Methods of Reducing Emissions
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 the mains supply. Consideration should be given to shield-
ing the supply cable of permanently installed welding equipment in
metallic conduit or equivalent. Shielding should be electrically con-
tinuous throughout its length. The shielding should be connected to
the welding power source so that good electrical contact is main-
tained between the conduit and the welding power source enclo-
sure.
Maintenance of the 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 adjust-
ment covered in the manufacturer’s instructions. In particular, the
spark gaps of arc initiation and stabilizing devices should be adjust-
ed and maintained according to the manufacturer’s recommenda-
tions.
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.
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 electrode 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, eg. 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 work pieces 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 direct connection to the workpiece, but in some coun-
tries 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.
Portions of the preceding text are extracted from:
• Australian/New Zealand standard AS/NZS 3652. Permission to
reproduce has been granted by Standards Australia and
Standards New Zealand. For further explanation, readers should
be referred to the standard itself.
• British Standards Institution standard BS EN 50199:1995.
Reproduced with permission of BSI under license number
2000SK0631. Complete standards can be obtained from BSI
Customer Services, 389 Chiswick High Road, London W4 4AL.
United Kingdom. (Tel +44 (0) 20 8996 9001).
Copyright of above text is property of Standards Australia,
Standards New Zealand and British Standards Institution.
Permission to reproduce the text must be obtained.
JAN ‘01
