Equations...

[whazza22]

Hi

Does anyone have any useful equations which are used reguarly in the industry? (eg. P = VxI)

Thanks

 

[scotsparky]

V =i/r

 

[Sintra]

R1+R2 for ring final circuits only :
R1+R2 = ((ph to ph)+(cpc to cpc))/4

Zs = (R1+R2)+Ze

Single phase Pfc = 230 / Ze

Three phase Pfc = (230 / Ze) x 2 rule of thumb

V = I x R

P = I squared x R

P = V x I

I = P / V


Adiabatic equation.

Voltage drop.

((mV/A/m) x Ib x L) / 1000

 

[andyb]

Try this

 

[whazza22]

Lovely Job guys!

Cheers

 

[JUD]

Ct equation to apply to voltage drop for reduced operating temp of cables

Ct = 230 + tp - ((Ca² x Cg²) - (Ib² / It²)) x (tp - 30) / 230 + tp

((mV/A/m x Ib x L) / 1000) x Ct

 

[BlueinSY2]

voltage drop = (mV/A/m) * Ib* L / 1000