Zs,Ze,R1+R2

[Bradley6969]

Zs=Ze+R1+R2 if you have R1+R2 and the Ze of cu through dead testing what is the need of doing an earth fault loop impedance test once you've energised the cu?

 

[LeeH]

You don't have too unless you have only measured r2.

 

[Bradley6969]

Ok so along as you have Ze of cu and R1+R2 no need for earth loop? As you can work out Zs

 

[LeeH]

Yes but I've got a feeling this could be a long thread. That's 101 of testing.

And I'll correct myself. 'R2'

 

[Wilko]

My 20p : Testing the earth fault loop confirms it actually works, and the value obtained can be cross checked with the expected values from design and Ze etc.

 

[Dave the spark]

Ok so along as you have Ze of cu and R1+R2 no need for earth loop? As you can work out Zs

Yes but I've got a feeling this could be a long thread. That's 101 of testing.

And I'll correct myself. 'R2'

Ze of cu?

 

[buzzlightyear]

by measurement or
by enquiry from the dno
or calculation

 

[Octopus]

Zs=Ze+R1+R2 if you have R1+R2 and the Ze of cu through dead testing what is the need of doing an earth fault loop impedance test once you've energised the cu?

It would confirm that the circuit is now live.....

 

[PEG]

It would confirm that the circuit is now live.....

...Which is a handy thing,if it is going to be spending most of it's life,in that state.

 

[Wilko]

Ok so along as you have Ze of cu and R1+R2 no need for earth loop? As you can work out Zs

BS7671 guide for Minor Works has performing the earth fault loop impedance test listed under Part3 : Essential Tests