Testing Question!!!

[ldworks]

What is the difference between Ze and Zs???
As far as i thought i knew Ze is the circuits earth loop impedance and the Zs is the installations incoming loop impedance??Real confused?!?!?!

 

[Spa Key]

Ze = EFLI up to the installation (usually measured @ consumer unit).

Zs = EFLI up to & including the installation (highest figure will usually be furthest point on circuit.)

Do you know what R1+R2 is? Zs is basically Ze + R1+R2. Zs can be calculated by measuring Ze and adding the value of R1+R2, giving Zs.

It's late and I'm sure someone will be along with a more in-depth post.

 

[trebor]

Ze is external earth loop impedance that is the service cable and network

Zs is total earth loop impedance ie the sum of Ze + R1 + R2

 

[Johno]

Basically,
Ze = resistance between L and E at supply
Zs = resistance between L and E at end of circuit

 

[AIM]

I remember it as:
Ze [External] ie from supply transformer to main intake position.
Zs [System] everything from supply transformer to the furthest point of consumers installation.

May be basic but it works for me!

 

[ldworks]

Thanks all think i get it now,was half way there but its clearer now.nice one all.