Arc Flash Personal Protective Equipment Research Articles

Arc-Flash Personal Protective Equipment Selection: A Simplified Constant-Energy-Line Based Table Method

A challenge faced by employers and workers is determining the appropriate rating of arc-flash personal protective equipment (PPE) when an engineering calculation has not been performed. Some standards include tables to assist the user in selecting arc-flash PPE for specific equipment types and voltage ranges. However, to use these and similar tabular methods requires the user to determine the fault current and the fault clearing time (FCT). Determining these values is at best difficult for the electrical worker, and in some circumstances, all but impossible.

Failures of Equipment Operating Under Normal Conditions: Arc-Flash Events can Happen during Normal Operation

Informational Note No. 1 for the definition of arc-flash hazard in National Fire Protection Association (NFPA) Standard 70E-2015 states, Under normal operating conditions, enclosed energized equipment that has been properly installed and maintained is not likely to pose an arc-flash hazard. Table 130.7(C)(15)(A)(a) of the standard instructs that arc-flash personal protective equipment (PPE) is not required for normal operation of a circuit breaker, switch, contactor, or starter if the equipment is properly installed, properly maintained, equipment doors and covers are closed and secured, and there is no evidence of impending failure. This article reviews three electrical equipment failures during substation circuit breaker operations where if personnel had followed the guidelines just described, they could have been seriously injured during these failures due to the arc-flash energy released at the time of the fault.

The Disconnect Between Electrical Safety and Accident Prevention: Protecting Workers from Arc Flash and other Hazards

The electrical safety climate in the united states was different 20 years ago. Many companies did not have well-developed electrical safety programs and written electrical work procedures. Electrical workers were not trained in arc-flash hazards and were not provided with arc-flash personal protective equipment (PPE). Unprotected workers were expected to perform work on and near energized circuits and equipment. Currently, most companies have established electrical safety programs and provide arc-flash training and PPE to their employees. Yet electrical injuries still occur. Electrical injuries can be attributed to 1) wellintended electrical safety programs falling short in their implementation and/or 2) workers failing to recognize the severe injury potential in a situation perceived as a low-level hazard. This article addresses some reasons why electrical safety programs fail to protect workers. It also discusses the potential arc-flash hazards associated with low-magnitude fault currents, which are illustrated through calculations.

The Possibility of Decreasing 50-Hz Electric Field Exposure near 400-kV Power Lines with Arc Flash Personal Protective Equipment

Various guidelines for the protection of human beings against possible adverse effects resulting from exposure to electromagnetic fields (EMFs) have been published with a view towards continual improvement; therefore, decreasing exposure is an important research area. The aim of this study was to investigate the possibility of decreasing electric field exposure with arc flash rated personal protective equipment (PPE), which in this case was a set of coveralls, and to compare the measurement results to calculations using the helmet-mask measuring system. We collected the data under a 400-kV power line. The test person stood on isolated aluminum paper, and the current between the ground and the aluminum paper was measured. When the test subject wore the arc flash PPE, the current to the ground was only 9.5% of the current measured when wearing normal clothes, which represents a clear decrease in exposure.

Shell of Protection: Arc-Flash PPE Research Update

This article is intended to update the practical research in arc flash while avoiding the specifics of any method. Personal protective equipment (PPE) in the electric arc has been evolving since the early 1990s. With the introduction of safety and health standards of the U.S. Occupational Safety and Health Administration (OSHA) and arc test methods of American Society for Testing and Materials (ASTM) International, the growth of PPE knowledge and the proliferation of PPE for electric arc has grown throughout the world. In 1995, National Fire Protection Association (NFPA) 70E began addressing arc-flash boundaries, and National Electrical Safety Code (NESC) added the safety requirements for electrical safety. Misunderstandings and errors in marketing still abound, but knowledgeable users, manufacturers, and researchers have helped to make materials more comfortable, protective, and available for many more work situations. OSHA 1910.269 in 1994, NESC in 2007, NFPA 70E in 2000, 2004, and 2009, and now Canadian Standards Association (CSA) Z462 have codified the clothing for electric arc. The International Electrotechnical Committee (IEC) standards use the open arc method developed in the United States and Canada and kept current in ASTM and the box method developed in Germany to offer an International Standards Organization (ISO) path for arcflash research. Brazil, Peru, Russia, South Africa, New Zealand, Australia, and, recently, China are codifying laws related to arc-flash PPE, so the international focus is critical. The international method ASTMF1959 is still the ipso facto standard because of its maturity and repeatability. Other methods provide insight to arc phenomena such as plasma and molten metal expulsion. Research continues with the purpose of improving worker protection, but the two characteristics of preventing ignition and melting materials from being used in arc flash and maintaining a shell of protection during the arc are not easily surpassed with other methods.

Designing a Site Electrical System With Arc Flash Energy Under 20 $ \hbox{cal}/\hbox{cm}^{2}$

There have been recent advances in equipment design and arc flash hazard assessment. It is possible to design a complete site electrical system, from transmission to distribution to utilization voltage, with the estimated arc flash energy below 20 cal/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (80 J/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) for all equipment. This paper describes a preferred design, where all workers can have proper arc flash personal protective equipment by using single-layer flame resistant everyday clothes and add a single-layer coverall for the higher energy tasks. Inherently safer design is in our future to reduce hazards and keep our workers safe.

Simplified Arc-Flash Hazard Analysis Using Energy Boundary Curves

A simplified analysis technique that allows for determination of required arc-flash personal protective equipment (PPE) based on IEEE Std. 1584-2002 and overcurrent protective device characteristics is presented. Unlike the simplified equations in IEEE 1584, this analysis technique can potentially be applied to any type of overcurrent protective device on any power system within the range of applicability of the IEEE 1584 empirical equations. While the method does not exactly calculate incident energy levels and flash protection boundaries at the buses under consideration, it does allow for an accurate determination of required PPE levels and maximum flash-protection boundary distances. This level of detail is often all that is required to enable workers to adequately protect themselves against arc-flash hazards. Actual studies performed in industrial facilities have shown that significant reductions in required data collection and analysis times have been achieved using the energy boundary analysis method.