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ARC FLASH IN THE ELECTRICAL WORLD


What is an Arc Flash? 
Arc flash temperatures can reach or exceed 35,000 F at the arc terminals. The massive energy released in the fault rapidly vaporizes the metal conductors involved, blasting molten metal and expanding plasma outward with extreme force. A typical arc flash incident can be inconsequential but could conceivably easily produce a more severe explosion (see calculation below). The result of the violent event can cause destruction of equipment involved, fire, and injury not only to the worker but also to nearby people.continue..


Arc Flash is the result of a rapid release of energy due to an arcing fault between a phase bus bar and another phase bus bar, neutral or a ground. During an arc fault the air is the conductor. Arc faults are generally limited to systems where the bus voltage is in excess of 120 volts. Lower voltage levels normally will not sustain an arc. An arc fault is similar to the arc obtained during electric welding and the fault has to be manually started by something creating the path of conduction or a failure such as a breakdown in insulation.continue..

The last few years has seen a great increase in the awareness of arc flash hazards and the injuries that result from the lack of adequate personnel protective equipment.  However, arcing faults and injuries have been around from the beginning uses of electricity.  So why is it just recently that actions are being taken to define and protect against this hazard?continue..


At the risk of sounding overly dramatic, the answer is: because people die.
Now it's hardly news that arc flash is deadly, and there is no one working in the industry today that is not already acutely aware of the danger. Everyone's heard that arc flash explosions can burn hotter than the surface of the sun, and if you haven't, well, they can. A December '07 article in the Journal of Safety Research said, "Next to the laser, the electric arc is the hottest event on earth, with recorded temperatures as high as 35,000° F" (Kowalski-Trakofler, Barret 598). That's pretty hot, so if you didn't know, now you do.continue..

An arcing fault is the flow of current through the air between phase conductors or between phase conductors and neutral ground. An arcing fault can release tremendous amounts of concentrated radiant energy at the point of the arcing in a small fraction of a second, resulting in extremely high temperatures, a tremendous pressure blast, and shrapnel hurling at high velocity. An electrical safety program, which contains an arc flash study, is crucial to minimizing injury that could result from an arc flash or blast. The safety program will define the equipment the employee will wear and the manner in which he or she will safely work. This paper looks at an arc flash study that consists of short-circuit analysis, protective device coordination, and arc flash analysis for meeting OSHA and NFPA 70E compliance standards.continue..

ETAP Arc Flash Analysis software brings you new and enhanced capabilities which allow for faster and easier assessment of arc flash hazards and arc flash incident analysis. Identify and analyze high risk arc flash areas in your electrical power system with greater flexibility by simulating and evaluating various arc flash mitigation methods in your arc flash study.continue..

ARCAD helps facilities create safer working environments for individuals who service electrical systems by providing On-Line and PC based software tools for Short Circuit and Arc Flash Hazard Analysis. NFPA requires that any panel likely to be serviced by a worker be surveyed and labeled. ARCAD service includes resources and tools allowing plant and facility managers and personnel to perform short circuit, incident energy, arc flash protection boundary, level of PPE calculations, and create customized arc flash warning labels themselves reducing the cost of obtaining compliance with OSHA, NFPA70E and new Canadian CSA Z462 standards.continue..

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