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.

Symbols

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)

Notes

  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,
x
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


Hazardous Areas – IEC and NEC/CEC Comparison

Depending where in the world you work, you are likely following one of two standards International Electrotechnical Commission (IEC) National...

Questions - Reputation and Privilege

Our question and answer system while letting you do exactly what it says, is much more.  It is a dynamic user driven system, where our users not only ask...

ABB Technical Guides - Motor Operation

ABB has produced a range of technical guides that offer concise explanations of the major technologies and technical issues in low voltage AC drives. ...

Induction Motor Calculator

Just added a page to the tools, which will allow you to calculate the synchronous speed, slip and rated torque for an induction motor. Not a particularly...

Magicians of Engineering

The other day I was reading 'Night of the New Magicians' by Mary Pope Osborn with my son.  The story is about a young boy and girl who travel back in time...

Maxwell's Equations - Gauss's Electric Field Law

Gauss's Electrical law defines the relation between charge ("Positive" & "Negative") and electric field.  The law was initially formulated by Carl Friedrich...

A mechanical engineering paper, some history and memories

I was digging in my bookshelf and came across the 80th Anniversary Association of Mine Resident Engineers, Papers and Discussions Commemorative Edition...

Understanding LV Circuit Breaker Fault Ratings

I think this post is going to be helpful to several of our readers. While the IEC low voltage circuit breaker Standard [IEC 60947-2, Low voltage switchgear...

myElectrical - Cable Sizing Tool Upgrade

Our IEE cable sizing was wrote a few years ago and had become rough around the edges. I thought it was time to give the tool a service. Unfortunately when...

Cost Performance and Time

Often us engineers get so bogged down in equations, using software, producing drawings and writing specifications that this becomes the sole focus.   ...

Our website uses cookies so that we can provide a better experience.
To learn more about what cookies are and how to manage them visit AboutCookies.org