New testing is scheduled to begin this month to investigate the arc-flash phenomenon. IEEE is collaborating with the U.S. National Fire Protection Association (NFPA) on the Arc Flash Collaborative Research Project.
An arc flash occurs when the insulation or isolation between electrified conductors is no longer sufficient to withstand the voltage between them, and an electric current arcs from one conductor to the next or from a conductor to ground. The flash, seemingly instantaneous and often accompanied by a thunderous blast, can cause concussion, blindness, deafness, and severe damage to the lungs, skin, and other tissue of anyone near the equipment. Each year in the United States more than 2000 workers are admitted to burn centers for treatment because of the phenomenon.
A number of laboratories around the globe are scheduled to carry out the tests, and their research is to be used to develop models that predict arc flash characteristics—ultimately strengthening industry standards for electrical safety and workplace practices. The current standards are IEEE Std. 1584 (IEEE Guide for Performing Arc Flash Calculations) and NFPA 70E (Standard for Electrical Safety in the Workplace).
The estimated cost of the test program is US $6.5 million. It will require up to three years to conduct the approximately 2000 tests, according to IEEE Life Fellow Ben Johnson, co-chair of the project. So far industry backers have contributed approximately $3.7 million.
IEEE Std. 1584 provides models and an analysis process for calculating the incident energy to which employees could be exposed during their work on or near electrical equipment. NFPA 70E addresses a range of electrical safety issues, including the arc flash hazards. The standard covers work practices, equipment maintenance and special requirements, and ways to ensure safety at an electrical installation. “We need to revise both standards to give industry the information it needs to better protect electrical workers,” Johnson says.
PARTNERSHIP PLAN The NFPA 70E community relies on IEEE Std. 1584 as a guide to how an electrical worker should use electrical equipment. To update the standards, IEEE and the NFPA formed their collaboration in 2005. The two groups, along with industry representatives, spent more than a year setting up a plan outlining the additional tests needed, as well as a fund-raising campaign to pay for them.
Major contributors to date include Bruce Power, Cooper Bussmann, Eaton Corp., Hydro One Networks, the InterNational Electrical Testing Association, Square D/Schneider Electric, Ferraz Shawmut, Procter & Gamble, the NFPA, Salisbury Inc., and Underwriters Laboratories, Inc.
COMPREHENSIVE TESTING The tests are expected to provide the data needed to develop equations and more. Researchers are measuring the thermal energy transfer of an arc flash, plus such effects as air pressure, sound waves, the toxicity of gases released from the conductors’ metals and insulating materials, and energy radiated at infrared, visible, ultraviolet, X-ray, and other wavelengths. Other tests will examine how enclosures affect the energy released in an arc flash, Johnson says. He expects information to be uncovered that manufacturers can apply to upgrade equipment and thereby mitigate the effects of an arc flash.
“We are going to do tests that have never been done before, and I expect that we’ll gain information that can lead to improved equipment as a result—which would be wonderful,” he says. “But that is not the objective; updating the standards to save lives is. Arc flash is a terrifying thing. Almost every day we lose someone in the U.S. due to electrical injury. So if we can save just one life, all this is worth doing.”