The Adiabatic Equation

This app is designed to make it easy and simple to determine and verify the cable size of the Main Earthing conductor required for supply into a domestic property in the UK using copper conductors. As well as for determining other earthing conductors and circuit protective conductors by calculation.

No longer do you have to grab for a pen, paper and scientific calculator. Simply enter the voltage, Ze reading and then select the disconnection time for the protective device of the circuit or installation, from the tables of protective devices given in the app.

The fault current displayed on the app calculation needs to be high enough to disconnect the protective device at the selected disconnection time as stated in the app.

The final reading to be entered is a cable factor for if the cable is to be bunched with others or on its own and all the information you need is given in the app.

The info in the app is fully updated to the 17th Edition Amd1 of BS7671 The Wiring Regulations.

The cable size given by the calculation in the app should then be adequate to deal with any fault generated that is to flow to earth.

This app is intended as a helpful guide, always consult BS 7671.