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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.
1.2 ELECTRICAL SECURITY
1.2.1 Connection to the network
Before connecting your equipment, you must check that:
- The meter, the safety device against over-currents, and the electrical installation are compatible with the maximum power and
the supply voltage of the welding power source (refer to the instructions plates).
- The connection, either single-phase, or three-phase with earth can be effected on a socket compatible with the welding power
source cable plug.
- If the cable is connected to a fixed post, the safety device against electric shocks will never cut the earth.
- The ON/OFF switch located on the welding power source is turned off.
1.2.1 Working area
The use of arc welding implies a strict respect of safety conditions with regard to electric currents. It is necessary to
check that no metal piece accessible by the operators and to their assistants can come into direct contact with a phase conductor
and the neutral of the network. In case of uncertainty, this metal part will be connected to the earth with a conductor of at least
equivalent section to the largest phase conductor.
Make sure that all metal pieces that the operator could touch with a non insulated part of his body (head, hands
without gloves on, naked arms, etc) is properly grounded with a conductor of at least equivalent section to the biggest supply
cable of the ground clamp or welding torch. If more than one metal ground is concerned, they need to be all interlinked in one,
which must be grounded in the same conditions.
Unless very special care have been taken, do not proceed to any arc welding or cutting in conductive enclosures,
whether it is a confined space or the welding machine has to be left outside. Be even more prudent when welding in humid or
not ventilated areas, and if the power source is placed inside (Decree dated 14.12.1988, Art. 4).
1.2.3 Risks of fire and explosion
Welding can originate risks of fire or explosion. You have to pay attention to fire safety regulation
- Remove flammable or explosive materials from welding area;
- Always have sufficient fire fighting equipment;
- Fire can break out from sparks even several hours after the welding work has been finished.
1.3 INDIVIDUAL PROTECTION
1.3.1 Risks of external injuries
Arc rays produce very bright ultra violet and infrared beams. They will damage eyes and burn skin if the operator is
not properly protected.
-The welder must be dressed and protected according to the constraints of his works impose to him.
-Operator must insulate himself from the work-pieces and the ground. Make sure that no metal piece, especially those
connected to the network, comes in electrical contact to the operator.
-The welder must always wear an individual insulating protection.
Protective equipments: gloves, aprons, safety shoes that offer the additional advantage to protect the operator against
burns caused by hot pieces, spatters, etc. Check the good state of this equipment and replace them before you are not protected
any more.
- It is absolutely necessary to protect eyes against arc rays.
- Protect hair and face against sparks. The welding shield, with or without headset, must be always equipped with a proper
filter according to the arc welding current. In order to protect shaded filter from impacts and sparks, it is recommended to add a
glass in front of the shield.
