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Hazard > Electric Arc Flash Protection
Electric Arc Flash Protection
Arc Flash Basics
"ARC FLASH" DEFINED; NFPA 70E Annex K-3
"When an electric current passes through air between ungrounded conductors and grounded conductors, the temperatures can reach 35,000°F. Exposure to these extreme temperatures both burns the skin directly and causes ignition of clothing, which adds to the burn injury. The majority of hospital admissions due to electrical accidents are from the arc-flash burns, not from shock. Each year more than 2,000 people are admitted to burn centers with severe arc-flash burns. Arc-Flash can and will
kill at distances of 10 ft."
The intense energy and very short duration of an electric arc flash represents a very unique exposure. Everyday work clothes made from regular cotton or poly/cotton fabrics, regardless of weight, can be readily ignited at some exposure level and will continue to burn adding to the extent of injury sustained from the arc alone. Arc Flash FAQ’s
In addition ASTM F1506 (StandardPerformance Specification for Textile Materials for Wearing Apparel for Use by Electrical Workers Exposed to Momentary Arc and Related Thermal Hazards) was developed to give minimum performance specifications for Protective clothing. The major two requirement of this specification was that the fabric is flame resistant, determined by using the standard vertical flame test (ASTM D6413) and have received an Electric Arc Rating or ATPV.
ASTM has developed a test method to assist in determining and comparing the protective capacity of various flame resistant fabrics ASTM F1959 (Standard Test Method for determining the Arc Thermal Performance Value (ATPV) of Materials for Clothing).
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