Short Circuit & Arc Flash Calculator

This page is a self-contained HTML document / JavaScript program, designed to rigorously calculate short circuit & arc flash values for a particular industrial facility.

A single-line diagram appears on the left.  Present is:  an off-site 3-phase utility supply;  a length of utility / supply conductors to an on-site service transformer;  main switchgear;  a feeder to another electrical building;  an OCPD to a motor circuit feeder;  a motor "starter", a motor circuit, and a motor.

Short circuit and arc flash values are calculated at several stages.  This allows creation & posting of SC/AF labels, for safety of maintenance personnel as well as compliance with NFPA 70E (© National Fire Protection Assoc., 2012).

"Text Boxes" and "Radio Buttons" are present, where I need to change data for the various equipment on site.
Each of these may be modified as desired.  All results will be re-calculated immediately.

N.B.  "View Page Source" on this page, and you are free to save, copy & redo as you wish.
And if you do, please retain the "footer"...

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Equipment ID:  

Utility Supply Voltage: kV Available Fault MVA: MVA Service Conductors to Supply Transformer Length (1-way): ft. Diameter: kcmil   Equipment Type: Cables Equipment Grounding: Grounded Ungrounded / Hi-Res.   Transformer Primary Protection: Fuse Circuit Breaker None / Unknown Service Conductors Resistance Ω Reactance Ω Total Impedance Ω   Conductors-only  Short Circuit ("S.C.") Current kA Conductors-only  S.C. MVA MVA Fault #1 Series S.C. MVA MVA Series S.C. Current kA (results1) Service Transformer Rated kVA: kVA Rated MVA MVA Secondary Voltage: kV "Percent Impedance": %Z   Equipment Type: Open Air Switchgear MCC / Panel Equipment Grounding: Grounded Ungrounded / Hi-Res.   Transformer Primary Protection: Fuse Circuit Breaker None / Unknown Primary Protection:                 (copied from above) Secondary Current (FLA) kA Bolted Fault / S.C. Current kA Bolted Fault / S.C. MVA MVA Fault #2 Series S.C. MVA MVA Series S.C. Current kA (results2) Main Switchboard - internal Bus Conductors Length (1-way): ft. Diameter: kcmil   Equipment Type: Open Air Switchgear MCC / Panel Grounding: Grounded Ungrounded / Hi-Res. Switchboard Disconnect - Feeder to Elec. Bldg.: Fuse Circuit Breaker None / Unknown   Main Bus Conductors Resistance Ω Reactance Ω Total Impedance Ω   Conductors-only  S.C. Current kA Conductors-only  S.C. MVA MVA Fault #3 Series S.C. MVA MVA Series S.C. Current kA (results3) Feeder to Elec. Bldg. Length (1-way): ft. Diameter: kcmil   Overcurrent Protection at Switchboard Disconnect for Motor: Fuse Circuit Breaker None / Unknown Equipment Type: Open Air Switchgear MCC / Panel Grounding: Grounded Ungrounded / Hi-Res.   Feeder Conductors to Elec. Bldg. Resistance Ω Reactance Ω Total Impedance Ω   Conductors-only  S.C. Current kA Conductors-only  S.C. MVA MVA Fault #4 Series S.C. MVA MVA Series S.C. Current kA (results4) Circuit to Motor Length (1-way) ft. Diameter kcmil   Grounding: Grounded Ungrounded / Hi-Res. Equipment Type: Open Air Switchgear MCC / Panel Protection: Fuse Circuit Breaker None / Unknown Motor Circuit Conductors Resistance Ω Reactance Ω Total Impedance Ω   Conductors-only  S.C. Current kA Conductors-only  S.C. MVA MVA Fault #5 Series S.C. MVA MVA Series S.C. Current kA   (results5) [All bracketed references are data & formulas from "ANNEX D"  of NFPA 70E, copyright National Fire Protection Assoc., 2012] Motor Rated H.P.: HP Rated kVA: kVA approx. Full Load Current: A   “Results shown are estimates, and may not be an accurate representation of your actual conditions.”