arc flash



Arc Flash is a massive electrical discharge, much like a lightening strike during a storm. It explodes with heat temperature that is 4 times hotter than the surface of the sun.

NFPA-70E Arc Flash Hazard Studies

Arc Flash Analysis Studies are required to ensure that maintenance personnel are aware of the hazards and can take proper precautions before working on live electrical equipment. An arc flash can occur when phase conductors come in contact with one another or ground.  This “Short Circuit” causes the air to ionize creating conductive plasma gas which generates large amounts of heat. This tremendous amount of heat, in the range of 35,000°, can severely burn human skin and ignite clothing resulting in further burning.

An Arc Flash Analysis of every non-residential facility is required by OSHA based on the General Duty Clause Section 5(a)(1) which requires an employer to furnish to its employees –

“employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employeesread more

Short Circuit (Fault) Studies, ANSI C.37 and IEC 909

Short Circuit (Fault Current) studies are required to insure that existing and new equipment ratings are adequate to withstand the available short circuit energy available at each point in the electrical system. Fault currents that exceed equipment ratings are capable of extensive equipment damage and are a serious threat to human life and limb. On large systems, short circuit studies are required to determine both the switchgear ratings and the relay settings.

No substation equipment, motor control centers, breaker panels, etc. can be purchased without knowledge of the complete short circuit values for the entire power distribution system. The short circuit calculations must be maintained and periodically updated to protect the equipment and the lives of workers. See “Determining When Studies are Necessary”

Never assume that new equipment is properly rated. All equipment ratings should be compared with an up-to-date base-line…read more