What is an electric arc?
An electric arc or arcing fault is a flashover of electric current through air from one exposed live conductor to another or to ground. Arc flash is a violent arc fault that can result in excessive heat exposure and burn injury. An arc flash hazard is different from an electrical shock or an electrocution hazard. Electrocution can occur with electrical amperages under 30 mA, which is far less than the electrical current that is necessary to produce an arcing fault. Shock hazards and arc fault hazards are two different categories of dangerous electrical occurrences, and each requires its own management and best practices policies.
Arc flash injuries
Electrical arcs create extremely high temperatures, and the heat that is produced causes the sudden expansion of air and, often, the vaporization of copper or aluminum conductors. When a solid vaporizes, it moves from a solid to a liquid to a gas in very quick succession, expanding in volume by many orders of magnitude in a very short time. This is the way that dynamite works, and the blast from an arc fault can be just as devasting, causing injury from heat, shrapnel and pressure waves.
Arc flash exposure
The exposure to arc flash depends on many factors including:
- the number of times that personnel work on live equipment;
- task complexity, the need to use physical force, available space and safety margins;
- training, skills, physical agility and coordination with assistants where appropriate;
- tools used; and
- the condition of the equipment.
WHENEVER POSSIBLE, ELECTRICAL WORK SHOULD BE CARRIED OUT ON DEENERGIZED CIRCUITS THAT HAVE BEEN LOCKED OUT AND TAGGED OUT!
Arc Flash Hazard Consultations
Arc flash hazards and best safety practices are described in depth in the 2009 standard 70E published by the National Fire Protection Association (NFPA). Industrial sites and factories should act aggressively to address potential arc flash hazards. The NFPA 70E standard is lengthy and difficult to navigate. X-L Synergy can expedite the analysis and implementation of plant safety installations and procedures.
Services that we offer include:
- Analyzing plant power to identify potential problem areas;
- Arc Flash Hazard training of managers and maintenance personnel; and
- Labeling of critical breakers and switchgear with relevant hazard levels and PPE requirements.