Electrode Configuration and 2018 IEEE 1584

The most frequently asked question that I receive regarding the 2018 edition of IEEE 1584 is:

“How do I determine the electrode configuration?” 

The 2002 edition was based on arc flash tests with the electrodes oriented in a vertical configuration. When performing an arc flash study based on the 2002 edition, there were only two options available – an arc flash in an enclosure and an arc flash in open air – both based on a vertical electrode configuration.

Since the original 2002 edition was published, additional research has shown that incident energy can be influenced by the electrode configuration.  As a result, many new tests were conducted using additional new electrode configurations including vertical electrodes that terminate into an insulating barrier as well as horizontal electrodes in an enclosure/box and in air.  This is in addition to the original vertical configurations in an enclosure and in air.  The additional configurations and the resulting Continue reading

2018 IEEE 1584 – 125 kVA Transformer Exception DELETED!

125 kVA – Going, going, gone!
After much speculation about the fate of the 125 kVA transformer “exception”, the 2018 Edition of IEEE 1584 – IEEE Guide for Performing Arc-Flash Hazard Calculations has finally been published and made it official.  The 125 kVA transformer exception has been deleted!

In its place is the new language:

“Sustainable arcs are possible but are less likely in three-phase systems operating at 240 V nominal or less with an available short circuit current below 2000A” Continue reading

New to Arc Flash, Short Circuit and Coordination studies

Hi. I currently work as an Engineer in the energy management field. I would like to branch off in to doing Arc Flash, Short Circuit and Coordination Studies. How would I go about doing this. I have been exposed to these reports but have never done them before. Would any of you happen to have any training material on how to get started? From what I’ve read I should learn how to do these reports manually then look in to getting software to aid with the reports. Not sure if it matters or not but I’m located in Canada. Thanks. READ MORE

2015 NFPA 70E – 10 Item Check Up

With the 2015 Edition of NFPA 70E being published and all of the changes that it brings, it is time to review your arc flash study, labels and overall practices.  There are many key areas that should be evaluated.  Here ten of the more important areas to look at to give your site a check up. Continue reading

Specifying Arc Flash Studies and IEEE 1584.1

An arc flash study can be a bit complicated if you are new to this field.  Knowing where to begin, what to include, how far to go, how to use the software etc. can seem like an insurmountable undertaking.  WORSE – you are going to contract the study and don’t know what to ask for.  The good news, there are many well qualified consultants that can help guide you through the process.  The bad news – there are plenty of people ready to take advantage of the situation once they realize this might be your first study. Continue reading

NFPA 70E – 2015 Edition – Update of Changes

NFPA 70E – Standard for Electrical Safety in the Workplace, was first published in 1979 and consisted of only one part, The 2015 Edition marks the tenth edition to NFPA 70E and with it, many sweeping changes. This article provides a review of the major changes to the latest edition of this important electrical safety standard. Continue reading

NFPA 70E Major Updates for the 2012 Edition – Part 2.

Although beginning with an erratic schedule with revisions to NFPA 70E being spaced anywhere from 2 to 5 years apart, this very important electrical safety standard is now on a regular 3 year revision cycle. In early 2011, I wrote an article about the significant changes that were about to be part of the 9th Edition, the 2012 Edition of NFPA 70E Standard for Electrical Safety in the Workplace. This article will take us a little further into the standard and address some changes that I was not able to include in the previous article. Continue reading

Arc Flash Hazard Calculation Studies

In the earlier years of NFPA 70E and the emergence of arc flash protection requirements, many people would use the NFPA 70E Hazard/Risk Tables to determine what arc rated PPE to wear. This approach continues to shift towards the use of arc flash studies involving incident energy and arc flash boundary calculations based on IEEE 1584. Continue reading

Arc Blast and 40 calories/centimeter squared

You look at the arc flash warning label and scratch your head. Danger! No PPE Category Found. No personal protective equipment (PPE) category? Now what? This type of language is often on arc flash warning labels when the calculated incident energy exceeds 40 calories per centimeter squared (cal/cm2). What is so special about the number 40?  The fear of the Arc Blast is not always well founded. Continue reading

Coordination and NEC 240.87

NEC 240.87 has addressed a potentially hazardous situation beginning with the 2011 edition. When selective coordination is critical, e.g., minimizing the extent of an outage, a common design practice is to use a main circuit breaker without an instantaneous tripping function and feeder breakers with one. Without an instantaneous, the main can time delay up to 30 cycles or 0.5 seconds greatly increasing the arc flash hazard.   Continue reading

How to Perform an Arc Flash Calculation Study

This article by Jim Phillips provides an overview of how to perform an arc flash study.  It was originally presented at the 2010 NETA Conference.  InterNational Electrical Testing Association.

Arc Flash Hazard Calculations Studies guide

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Arc Flash Calculation Study
Many separate codes, standards and related documents are available regarding electrical safety and arc flash. However, a standardized recommended practice or guide that integrates all of the components into an Arc Flash Calculation Study does not presently exist. Continue reading

Simplifying Arc Flash Studies – Select the Arc Rating First

Begin at the End – What Answer Would You like to Have? Simplifying the arc flash study – Would you like to know a little secret about how to simplify an arc flash studies? Perform the study backward. Well, not actually backward, it just seems that way
Performing the study: Arc rating > incident energy. An arc flash study is one method that can be used to determine the level of arc-rated clothing and personal protective equipment that is appropriate for protection from the thermal energy of an arc flash. Continue reading