Adiabatic equation

[Jordanh1992]

Can anyone tell me how I work out K when theirs not correction factors?

 

[Guest55]

k values are given in the regs book depending on the type of cpc.
correction factors are not used in the adi. equation.

 

[Jordanh1992]

Yeah I'm looking at them now, my CPC is 1.0mm2 I still don't get how I work out K, new to the adiabatic equation...

 

[KAS1]

Why do you need to work it out, it's a tabulated value isn't it?

 

[Jordanh1992]

Yeah but theirs 4 tables with different values for K... Tables 54.2.... To .6

 

[GLENNSPARK]

whats the material?...
factor of K for copper is 115...so
assuming its this we go:
lets say the current needed to acheave a disconnection time of 5s was 160A we can go:
160*X5=128000.....we then apply the square root to this so:
128000 square root=357,7708764...now we divide this by our factor of K (which in the case of copper is 115)...so:
357.7708764/115=3.11 (to 2 decimal places)....this would be the min. CSA required