Lincoln Electric POWER MIG 140 Operator's Manual page 6

ELECTROMAGNETIC
COMPATIBILITY (EMC)
ConformanCe
Products displaying the CE mark are in conformity with European
Community Council Directive of 3 May 1989 on the approximation
of the laws of the Member States relating to electromagnetic
compatibility (89/336/EEC). It was manufactured in conformity
with a national standard that implements a harmonized standard:
EN 60974-10 Electromagnetic Compatibility (EMC) Product
Standard for Arc Welding Equipment. It is for use with other
Lincoln Electric equipment. It is designed for industrial and
professional use.
IntroduCtIon
All electrical equipment generates small amounts of electro-
magnetic 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 affect
many kinds of electrical equipment; other nearby welding
equipment, radio and TV reception, 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 estab-
lishment.
InstallatIon and use
The user is responsible for installing and using the welding
equipment according to the manufacturer's instructions. If electro-
magnetic disturbances are detected then it shall be the respon-
sibility of the 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
(grounding) the welding circuit, see Note. In other cases it could
involve construction of 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 reasons
according to national codes. Changing the earthing arrangements should
only be authorized by a person who is competent to access whether the
changes will increase the risk of injury, e.g., by allowing parallel welding
current return paths which may damage the earth circuits of other equip-
ment.
assessment of area
Before installing welding equipment the user shall make an
assessment of potential electromagnetic problems in the
surrounding area. The following shall be taken into account:
a. other supply cables, control cables, signaling and telephone cables;
above, below and adjacent to the 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 time of 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 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.
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
adjustments covered in the manufacturers instructio ns. In
particular, the spark gaps of arc striking and stabilizing devices
should be adjusted and maintained according to the
manufacturer's recommendations.
Welding Cables
The welding cables should be kept as short as possible and
should be positioned close together, running at or close to 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,
not 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 work piece
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 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.
SAFETY