Do I use zdb or ze when calculating zs values on am2?

[Uplight99]

Got my am2 coming up on Tuesday and I know I have to calculate my Zs readings

Maybe I’m overthinking this but am not sure if I need to use the Ze (which is apparently given to me) or my measured Zdb from my three phase panel in the equation. I have heard different answers, would be great if someone could clarify this for me. I assumed it would be Zdb+(R1+R2)

Also do I need to use the 80% OSG value or the value in bs7671

 

[Uplight99]

You don't need brackets when it is written with items above and below the line as they have done. But the way you wrote it is incorrect, ie. R1 + Rn / 4

Ok.

So I would write R1+Rn = (r1+rn)/4
Then lay it out like I previously did

 

[DPG]

Ok.

So I would write R1+Rn = (r1+rn)/4
Then lay it out like I previously did

Yes that would be a correct format.

 

[Uplight99]

Yes that would be a correct format.

Thanks for the help