Technical Articles

Technical Articles

Neutral Grounding Resistor

Impedance Grounding and Arc Flash

A short circuit happens when energized conductors accidentally make contact with each other and/or to ground. When that connection forms, the load and its impedance is bypassed resulting usually resulting in a very high magnitude of current. There are several fault types—three-phase, phase-to-phase, and line-to-ground, but the line-to-ground fault is by far the most common. You’ll often see numbers in the 70–80% of all faults falling into this category. Some say this number is even higher. Why so many line-to-ground

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When Horizontal Bus is NOT HCB

Question:I have a switchboard with horizontal bus. Should I use the HCB model? Short answer:Not necessarily. Wait! What? Horizontal might not be horizontal? NFPA 70E requires performing an arc flash risk assessment which usually means using IEEE 1584 equations via software to conduct an arc flash study. This requires the selection of what is known as the equipment electrode configuration. One of the most misunderstood configurations is HCB. Let’s clear up a common misunderstanding. HCB stands for Horizontal Conductors in

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Arcing Fault Current, NFPA 70E and IEEE 1584

IEEE 1584 defines arcing fault current as the reduced current that flows during an arc flash event, differing significantly from bolted fault current. Understanding this distinction is critical for accurate incident energy calculations, arc flash studies, and NFPA 70E compliance.

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IEEE 1584.2 Standard

NEW! IEEE 1584.2 was Recently Published

IEEE 1584.2 was recently published! The full title is: IEEE Guide and Checklists for Data Collection for Performing an Arc-Flash Hazard Calculation Study in Accordance with IEEE Std 1584™ and IEEE Std 1584.1™ for Systems Operating at Three-Phase 50/60 Hz AC 1000 V and Below This newest addition to the IEEE 1584 family complements the existing standards: IEEE 1584 – 2018: IEEE Guide for Performing Arc-Flash Hazard Calculations IEEE 1584.1 – 2022: IEEE Guide for the Specification of Scope and

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