Tools

Cable Sizing Application

Click here to register to use our cable sizing application

What Changed

So that we can focus all our efforts on our new application, we have retired our myElectrical.com cable sizing calculator. We recommend you now use our main cable sizing application over at myCableEngineering.com.

myCableEngineering.com

Cable Sizing Software - select, size and manage your power cables using myCableEngineering. All your cables, for all your projects.
  • LV and MV cables up to 33 kV with current capacity in accordance with BS 7671, ERA 69-30 and IEC 60502.
  • Positive and zero sequence impedance to IEC 60609. Voltage drop in accordance with CENELEC CLC/TR 50480.
  • Project management and team collaboration, with clear easy to read calculations and reports.

Our software is the only cloud-based solution and has been built from the ground up to be fully responsive - meaning you can access your cables from anywhere and on any device, desktop, tablet or smartphone.

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

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...

Why a Sine Wave?

I received this question by email a few weeks. First thoughts was that it is a product of the mathematics of rotating a straight conductor in a magnetic...

RLC Circuit, Resistor Power Loss - some Modelica experiments

Modelica is an open source (free) software language for modelling complex systems. Having never used it before, I thought I would download a development...

Fault Calculations - Typical Equipment Parameters

A frequent problem in fault calculations is the obtaining of equipment parameters.  While it is always preferable to use the actual parameters of the equipment...

Photovoltaic (PV) - Utility Power Grid Interface

Photovoltaic (PV) systems are typically more efficient when connected in parallel with a main power gird. During periods when the PV system generates energy...

Photovoltaic (PV) Panel - Performance Modelling

In an earlier note on the site [Photovoltaic (PV) - Electrical Calculations], the theory of solar (PV) cell calculations was introduced.  In particular...

DC Component of Asymmetrical Faults

The image (reproduced from IEC 60909) shows a typical fault in an ac system.  From the illustration it can seen that there is an initial dc component ...

Cable Sheath and Armour Loss

When sizing cables, the heat generated  by losses within any sheath or armour need to be evaluated. When significant, it becomes a factor to be considered...

Periodic Electrical Installation Inspection – How Often?

How often installations are inspected is up to the owner of the installation, provided such durations do not exceed any regulatory maximums in force. ...

Copyright Infringement

myElectrical does not support or promote the use of copyrighted material without the copyright owner's consent. If you believe that material for which...

Footer
(click here to extend)
Copyright (c) 2026 myElectrical