The Adiabatic Equation for calculating the cpc (circuit protective conductor) and earth minimum csa sizes of earthing conductors.
The Adiabatic Equation Calculator takes into account of the following
t = Disconnection time (seconds)
k = Conductor k value (From BS 7671 tables)
la = Fault current (PEFC in Amps)
I² = la x la
Values of K are obtained from the tables within BS 7671:
- Table 54.2 : Conductor not incorporated in a cable and not bunched with cables.
- Table 54.3 : Conductor incorporated in a cable or bunched with cables.
- Table 54.4 : Sheath or armour of a cable.
- Table 54.5 : Steel conduit or trunking.
Disconnection times (t) are obtained from the maximum operating time/current characteristics tables within BS 7671:
- Fig 3A2 (a,b) : BS 3036 semi-enclosed fuse
- Fig 3A3 : (a,b) : BS 88-2.2
- Fig 3A4 : BS EN 60898 / 61009-1 MCB/RCBO type B
- Fig 3A5 : BS EN 60898 / 61009-1 MCB/RCBO type C
- Fig 3A6 : BS EN 60898 / 61009-1 MCB/RCBO type D
- BS 1361 Fuse
How to use:
1) Input your voltage value
2) Input your Zs value
3) Select protective device
4) Select protective device rating
5) Select conductor type
6) Select conductor material
7) Press calculate
This Adiabatic Equation calculator app is designed for Android phones and tablets, don't forget to check out our other great selection of electrical apps for Android.