Technical Articles

Short Circuit Analysis and Fault Current Calculations

Fig. 4 Staged Arc Flash Test

Zero-Sequence Impedance and Incident Energy

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…

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NFPA 70E Annexes

2018 NFPA 70E Informative Annexes

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…

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Jim Phillips - IEC Office in Geneva Switzerland

IEC TC 78 Live Working Standards

By Jim Phillips, P.E. International Chairman IEC TC 78 As the International Chairman of IEC TC 78, a frequent question that I receive is “What is IEC TC 78?” IEC is the acronym for the International Electrotechnical Commission based in…

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FREE Download Arc Flash Hazard Calculation Guide

The 2017 NEC and Arc Flash

By Jim Phillips The 2017 National Electrical Code (NEC) contains several changes regarding arc flash: Download FREE Arc Flash Calculations 110.16(B) Arc-Flash Hazard Warning of Service Equipment 240.87 Arc Energy Reduction (Circuit Breakers) 240.67 Arc Energy Reduction (Fuses) The severity…

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