Tweco 201 ts Thermal Arc - Manual (Page 22)

Installation, Operation And Setup 3-4 Manual 0-5149
THERMAL ARC 201 TS INSTALLATION
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.
C. Methods of Reducing Electromagnetic Emissions
1. 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 it’s 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.
2. Maintenance of 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 manufacturer’s instructions. In particular, the spark gaps of
arc striking and stabilising devices should be adjusted and maintained according to the manufacturer’s
recommendations.
3. 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.
4. 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 the metallic components and the electrode at the same time. The operator
should be insulated from all such bonded metallic components.
5. Earthing of the Workpiece
Where the workpiece is not bonded to earth for electrical safety, nor connected to earth because of it’s
size and position, e.g. 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
the workpiece 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 countries where direct connection is not permitted, the bonding should be
achieved by suitable capacitance, selected according to national regulations.
6. Screening and Shielding
Selective screening and shielding of other cables and equipment in the surrounding area may alleviate
problems of interference. Screening the entire welding installation may be considered for special
applications.
3.05 SETUP FOR WELDING
NOTE
Conventional operating procedures apply when using the Welding Power Source, i.e. connect
work lead directly to work piece and electrode lead is used to hold electrode. Wide safety margins
provided by the design ensure that the Welding Power Source will withstand short-term overload
without adverse effects. The welding current range values should be used as a guide only. Current
delivered to the arc is dependent on the welding arc voltage, and as welding arc voltage varies
between different classes of electrodes, welding current at any one setting would vary according to
the type of electrode in use. The operator should use the welding current range values as a guide
then fine tune the welding current to suit the application.