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SAFETY

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Electromagnetic Compatibility (EMC)

 

 

 

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 manufacturerʼs recommenda-

 

 

 

tions. 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 equip-

 

 

 

ment, 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 manufacturerʼs recommendations.

 

 

 

All access and service doors and covers should be closed and properly fastened when the welding equip-

 

 

 

ment 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 manufacturerʼs 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 workpiece

 

 

 

increasing the risk of injury to users, or damage to other electrical equipment. Where necessary, the connec-

 

 

tion 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.

 

 

 

Screening and Shielding

 

 

 

Selective screening and shielding of other cables and equipment in the surrounding area may alleviate prob-

 

 

 

lems of interference. Screening of the entire welding installation may be considered for special applications.

 

 

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1

Portions of the preceding text are contained in EN 60974-10: “Electromagnetic Compatibility (EMC) prod-

 

 

 

 

uct standard for arc welding equipment.”

 

 

L10093 3-1-96H

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Lincoln Electric IM958 manual Safety