Zero-Sequence Impedance and Incident Energy: A question that I am often asked either on-line or in one of my arc flash training classes is in regards to incident energy calculations and line-ground short circuit current: “Since it is possible for the line-to-ground short circuit current…
As the International Chair of IEC TC78 Live Working Committee, I am excited to announce the recent publication of the second edition of IEC Standard 61482-2 Live working – Protective clothing against the thermal hazards of an electric arc –…
I have been receiving many questions lately about the status of the next edition of the standard: IEEE 1584 – IEEE Guide for Arc-Flash Hazard Calculations. As Vice-Chair of the IEEE 1584 working group, I would like to provide an…
When the topic of incident energy above 40 calories per square centimeter (cal/cm^2) comes up, the discussion can be quite interesting. People will sometimes refer to the high values in terms of a bomb or some other sensationalized description. Although…
By Jim Phillips March has been a busy month for me with Standards Committee work. I just returned home from three weeks of travel that included IEEE Standards meetings in Ft. Worth, Texas and various IEC meetings held at British…
Short Circuit Calculations – Transformer and Source Impedance An infinite bus transformer short circuit calculation can be used to determine the maximum short circuit current on the secondary side of a transformer circuit using only transformer nameplate data. This is…
Almost half of the pages in the 2018 edition of NFPA 70E are devoted to 17 informative annexes. Even though technically the annexes are not part of the mandatory text, there is an incredible amount of additional information, examples and…
Global Use of IEEE 1584: IEEE 1584 – It’s a Small World The world’s electrical systems do not discriminate when it comes to electrical safety. Electric shock, electrocution and arc flash hazards can occur anywhere on the planet that has electricity. An interesting side note…
New Exception 130.5(H) Exception No. 2 – Arc Flash Hazard Label Information May Not Be Required. It is amazing how the requirements for arc flash labeling have evolved with each new edition of NFPA 70E. Known as Arc Flash Warning…
The 2018 Edition of NFPA 70 provides a new definition for the term “Condition of Maintenance” : BUY NOW: 2018 NFPA 70E Changes Part 1 The state of the electrical equipment considering the manufacturers’ instructions, manufacturers’ recommendations, and applicable industry…
English 
Spanish 
