Drum roll please! The second edition of IEEE 1584.1, or “dot one” as we often call it, was recently released. Not to be confused with IEEE 1584, IEEE Guide for Performing Arc-Flash Hazard Calculations, IEEE 1584.1 has a different scope and a much longer title: IEEE Guide for the Specification of Scope and Deliverable Requirements for an Arc-Flash Hazard Calculation Study in Accordance with IEEE Std 1584.
The scope states, “This standard provides guidance for the specification and performance of an arc-flash hazard analysis, in accordance with the process defined in IEEE Std 1584, IEEE Guide for Performing Arc-Flash Hazard Calculations. It provides the minimum scope and deliverables for an arc-flash study.”
This article refers to IEEE 1584 and IEEE 1584.1, so whether “dot one” is included in the standard number is quite important.
Why IEEE 1584.1?
Arc flash calculations and studies have gone through quite an evolution from the early days of theoretical equations introduced by Ralph Lee in the early 1980s, to empirically derived equations introduced in the paper “Predicting Incident Energy to Better Manage the Electric Arc Hazard on 600V Power Distribution Systems.” Building on this earlier work, IEEE 1584 was first published in 2002, and software companies quickly integrated the equations of this landmark standard into their programs. That was the dawn of commercial arc flash studies.
The 2004 edition of NFPA 70E, Standard for Electrical Safety in the Workplace, introduced requirements for specific arc flash information to be listed on the equipment (arc flash) labels. Arc flash studies were now starting to be more common.
However, in the early years, there was significant confusion and inconsistency with arc flash studies, sometimes due to lack of sufficient experience or the facility owner not understanding what was required. Sometimes both.
It was not unusual to hear an owner say, “I need stickers on the equipment so we are not in trouble with OSHA.” They would receive a proposal for an arc flash study and almost have a heart attack. The follow-up comment would often be, “Can’t you just use a typical label or a typical study?”
To provide owners and those performing the study much-needed guidance for specifying and performing arc flash studies in accordance with IEEE 1584, the first edition of IEEE 1584.1 was developed.
2022 IEEE 1584.1—new and improved
The second edition of IEEE 1584 was published in 2018, which included the addition of electrode configurations, adjustments for enclosure sizes and many other important changes. It was now time to bring the first edition of IEEE 1584.1 into alignment with the second edition of IEEE 1584.
Data collection and scope of work: “I thought you were providing that information,” answered by, “No, we assumed you were.” Sound familiar? Misunderstandings happen between clients and consultants, but it’s better if they can be avoided.
IEEE 1584.1 provides checklists to assist in defining what will be included in the study and who is responsible for providing the information. For example, does a single line diagram need to be created or updated, and will the owner provide existing single lines? Who provides data regarding overcurrent devices? Who obtains electric utility company data? Checklists are an important part of planning the arc flash study.
Arc flash study report: Not all arc flash study reports are the same. Aside from the obvious, inevitable technical differences, some may create a very detailed comprehensive report and others may provide a very minimalist one. IEEE 1584.1 provides a list of suggested information to be included in an arc flash report.
Short-circuit and coordination studies and other data: Arc flash calculations based on IEEE 1584 require a significant amount of input data, such as the bolted fault current and protective device clearing time that defines the arc duration. This information is typically obtained from the results of a short-circuit and coordination study, which is not directly addressed by IEEE 1584.1.
Historically, subjects such as short-circuit and coordination studies could be found in several different standards. That could result in information becoming out of sync between the standards over time. To resolve this problem, each subject has been or will be redeveloped into its own unique standard as part of the IEEE 3000 series standards. Short-circuit and protective-device coordination studies are addressed by standards such as IEEE 242 and IEEE 3002.3, rather than IEEE 1584.1.
To learn more or order a copy of IEEE 1584.1, go to https://standards.ieee.org/ieee/1584.1/7468.
Although arc flash studies have become more commonplace, one very important difference separates arc flash from other power system studies: if a mistake is made, it could directly affect human life. Therefore, all guidance is welcome!