How to form a bounding arc flash study for your site

This paper presents the concept, design, implementation and application of an original bounding study for arc flash. A bounding arc flash study, which is defined and bound by the characteristics of a particular site or plant, defines arc flash guidelines for electrical workers when the traditional method of calculation outlined in IEEE 1584 is inconvenient to use. The NFPA 70E offers default values in tables that are often used when a traditional study has not been achieved; however, these tables are not representative of all situations common to the workplace. The bounding arc flash study described is primarily designed for temporary power installations and for plants or sites that have not collected the data required by traditional methods. The design of the study is discussed in length so the process can be duplicated with specific adjustments required for your site or plant. Within the study, a typical range of equipment types is identified and then tested against an array of input data, such as short circuit levels, voltage levels, protective device settings, transformer sizes, cable lengths and emergency generation design. The paper explains how new developments affect this type of study and how to update accordingly.