Power sources for MMA welding and associated pieces of equipment, such as electrode holders, leads and connectors all require electricity to operate. Power sources may be AC or DC, operate from a three-phase supply, from industrial single-phase supply or even from a domestic power supply, and are often designed to operate with high open circuit voltages (OCV).
Primary and secondary connections should be completed by competent persons.
It should always be remembered that electric shock can kill.
Due to the potential severity of the hazard, the following is a guide on what to do before any MMA welding is started to reduce the risk of an electrical accident:
- Only qualified personnel should be allowed to install MMA equipment. Whoever does install the equipment must ensure that it complies with national standards, any local regulations, the manufacturer's instructions and workpiece 'earthing' requirements.
During welding the possibility of electric shock is one of the most serious risks encountered by a welder.
Most electrical accidents occur as a result of carelessness, poor workmanship or due to faulty equipment.
The following points provide a guide on what to do to reduce the risks:
- Welders should not remove panels from a welding power source if it stops working correctly. Touching a lead inside the welding set with the power still on can result in a serious primary voltage shock.
- Never ignore a blown fuse, it is a warning that something is wrong.
The following practices will help prevent electrical accidents:
- When welding is temporarily interrupted electrode holders should be placed where they are safe and the electrode cannot accidentally arc. It is safer if the electrode is removed from the holder.
- If welding is to be stopped for any length of time the welding set should be switched off.