What Does Arcing Mean?
Arcing, also called “electrical arcing” occurs when an electric current flows through the air, from one conductive point to another. In occupational safety contexts, arcing is associated with a flaw in an electrical circuit that causes the electrical current to cease travelling along its intended path and to instead jump across a shorter path, from one conductor to another.
The heat and light energy emitted by the arcing current is called an “arc energy” and may cause significant injury or death to exposed workers. When undesired arcing is caused by an equipment failure, the situation is referred to as an “arc fault”.
Safeopedia Explains Arcing
Undesired arcing occurs when equipment is damaged in such a way that the conduction of the current through the equipment becomes uncontrolled, producing an arc fault. This causes the current to ionize the air, which creates a conductive pathway through the air to another conductor—either a grounded object or person. As energy travels through the air, the resulting arc flash may produce temperatures of over 10,000 oF (5537 oC).
Arcing can be caused by numerous flaws in electrical systems including; breaks in the insulation, the presence of impurities such as dust or rust, overloads, and damage to the conductors or wires. Further, replacement or refurbishment of electrical equipment can be necessary to prevent arcs even if the equipment is kept in good condition as degradation of electrical equipment can occur simply as a consequence of its usage over time.
In addition to the dangers posed by arc flashes, the heat generated by arcing can also cause fires if the arc strikes against flammable materials. This is why OSHA, NFPA, and other occupational safety organizations require electrical workers to wear protective garments that will not melt or burn upon contact with an arc flash. Not all instances of arcing are undesired; as the name suggests, different types of arc welding (i.e., MIG welding) rely on the purposeful and controlled production of electrical arcs.
In the United States, there are numerous legal and consensus standards that are designed to protect against arcing hazards. The most recognized of these is the NFPA 70e standard, which OSHA relies upon to determine whether employers are providing workers with sufficient protection against electrical hazards.