Arc Flash Calculator

Calculation of arc flash incident energy and protection boundary in accordance with IEE Std. 1584 'IEEE Guide for Performing Arc-Flash Hazard Calculations'.

Sytem Details

Equipment Details

Arc Flash

Tip: registered users can save calculations.


V - system voltage (kV)
Ibf - bolted three phase fault current (kA)
Ia - arcing current (kA)
E - incident energy (J/cm2)
EB - - incident energy at boundary distance (J/cm2)
En - - normalized incident energy (J/cm2)
t - arcing time (s)
D - distance from arc to person (mm)
CB - distance of boundary from arc point (mm)


  1. Boundary Energy can be set at 5.0 J/cm2 for bare skin or at the rating of any proposed PPE.
  2. The limit of 5.0 J/cm2 is that at which a person is likely to receive second degree burns.
  3. To convert J/cm2 to cal/cm2 multiply by 0.239

Gap and distance factors
Voltage (kV) Equipment Type Typical gap between
conductors (mm)
Distance factor,
0.208 - 1

Open Air 10-40 2.000
Switchgear 32 1.473
MCC and Panels 25 1.641
Cable 13 2.000
>1 - 5 Open Air 102 2.000
Switchgear 13-102 0.973
Cables 13 2.000
>5 -15 Open Air 13-153 2.000
Switchgear 153 0.973
Cables 13 2.000

For a more detailed explanation of the calculation, please see: Arc Flash Calculations Post

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