Risks from weld-
ing current
Meandering weld-
ing currents
12
The following components are responsible, amongst other things, for the de-
gree of toxicity of welding fumes:
-
Metals used for the workpiece
-
Electrodes
-
Coatings
-
Cleaners, degreasers, etc.
The relevant material safety data sheets and manufacturer's specifications for
the listed components should therefore be studied carefully.
Flammable vapours (e.g. solvent fumes) should be kept away from the arc's
radiation area.
An electric shock is life threatening and can be fatal.
Do not touch live parts either inside or outside the device.
During MIG/MAG or TIG welding, the welding wire, the wirespool, the drive
rollers and all metal parts that are in contact with the welding wire are live.
Always set the wire-feed unit up on a sufficiently insulated surface or use a
suitable, insulated wire-feed unit mount.
Make sure that you and others are protected with an adequately insulated, dry
temporary backing or cover for the earth or ground potential. This temporary
backing or cover must extend over the entire area between the body and the
earth or ground potential.
All cables and leads must be complete, undamaged, insulated and adequately
dimensioned. Loose connections, scorched, damaged or inadequately dimen-
sioned cables and leads must be repaired/replaced immediately.
Do not sling cables or leads around either the body or parts of the body.
The electrode (rod electrode, tungsten electrode, welding wire, etc) must
-
never be immersed in liquid for cooling
-
never be touched when current is flowing.
Double the open circuit voltage of a welding machine can occur between the
welding electrodes of two welding machines. Touching the potentials of both
electrodes at the same time may be fatal under certain circumstances.
Switch off unused devices.
If the following instructions are ignored, meandering welding currents can de-
velop with the following consequences:
-
Fire hazard
-
Overheating of parts connected to the workpiece
-
Irreparable damage to ground conductors
-
Damage to device and other electrical equipment
Ensure that the workpiece is held securely by the workpiece clamp.
Attach the workpiece clamp as close as possible to the area that is to be weld-
ed.
If the floor is electrically conductive, the device must be set up with sufficient
insulating material to insulate it from the floor.