For calculating or verifying cpc and earthing conductor sizes
CPC EARTH SIZE CALCULATOR
The Adiabatic Equation Calculator is for calculating the absolute minimum permitted circuit protective conductor size, or for verifying an existing protective conductor is adequately sized.
CALCULATING PROTECTIVE CONDUCTOR SIZE
The current edition (at time of writing) of BS 7671 states:
The cross-sectional area of each protective conductor, other than a protective bonding conductor, shall be:
- (i) Calculated in accordance with regulation 543.1.3 or
- (ii) Selected in accordance with regulation 543.1.4
This Adiabatic Equation Calculator App is designed to assist in satisfying option (i) above.
- Calculating the Adiabatic Equation need not be daunting, get the app!
- Conductor mm²
- la = Fault current
- I² = Fault current²
- k = Conductor k value
- t = Disconnection time
Don’t take our word for it – here’s what other app users say:
Seem to work spot on , comes up with the same answer as i calculate on paper.
Awesome app so easy to use with correct results.
The Adiabatic Equation Calculator couldn’t be any easier to use, just enter your voltage and Zs values, then select your choice from the following drop down options.
- Protective Device
- Protective Device Rating
- Protective Conductor Type
- Protective Conductor Material
Then tap the “Calculate” button to get the results, it is that simple!
DEVICE TYPE | DEVICE RATING
We have pre-programmed in the operating time / current characteristics for the protective device circuit breakers, fuses and RCBO’s so you don’t need to look them up.
- Depends on selected protective device
TYPE | MATERIAL
Select your choice of protective conductor type, then conductor material. The options available for protective conductor material depends on the selected conductor type.
Types of Protective Conductors:
- Single cable not bunched
- Incorporated in a cable or bunched with cables
- Sheath or armour of cable
- Steel conduit or trunking
Protective Conductor Material:
Protective Conductor k Values:
Conductor k values have already been set, your protective conductor type and conductor material selections will automatically set the values of k for you.
Once you have completed the quick steps mentioned above, tap the calculate button to get the results.
In addition to calculating the protective conductor size the Adiabatic Equation calculator also displays all the other relevant calculation results associated with the final calculation of the earth / earthing conductor / protective conductor size.
Adiabatic Equation Calculation Results
- Conductor size mm²
Demo video may show an older version of the app
The Adiabatic Equation Calculator
Get the Adiabatic Equation app to start calculating earth & cpc sizes.
- Easy to use
- Pre-set formulas
- Quick and instant results