Zs is lower than my R1+R2

[HLR Electrical]

I’ve just changed a few lights for a customer and I rarely do testing so not very knowledgeable on it. I tested 3 lighting circuits.
1st circuit - Zs is 0.48 - r1+r2 is 0.55
2nd circuit - Zs is 0.75 - r1+r2 is 1.02
3rd circuit - Zs is 1.06 - r1+r2 is 1.55

All breakers are B type 10A BS en 60898

What’s your advice/opinion on this?

Thanks

 

[Dustydazzler]

Zs will pick up parallel paths to earth , where as R1+R2 is just the circuit cable you are testing

 

[cireland]

Did you zero the leads for R1+R2?

 

[timhoward]

As said above parallel paths is one explanation.
Other that curiosity I wouldn't worry as even the higher readings are well within the permitted max Zs for a B10 device.
Did you measure a Zs at the board too?

 

[Markyd]

You rarely do testing!!!!!!!!

 

[Deleted account]

You rarely do testing!!!!!!!!

Maybe he is a first fix guy Or works in a team.

 

[Dustydazzler]

You rarely do testing!!!!!!!!

Half the sparks that I have worked with over 25 years , 'rarely do any testing' either ( unless you class the bang test as testing)

 

[telectrix]

what is testing? is it a male hormone?