Marginally high CPC end to end readings

[aliensbrains]

Sure this has come up before but yesterday testing after adding a spur and end to end readings on CPC come out about 0.2ohm over expected reading (was expecting about 1ohm from LL & NN (0.65)

Checked all sockets I could see (some were very old so suspect the sockets themselves might be a contributing factor) other possibility is JB under floor.

Question is would you just report this on meiw, start ripping up floorboards, recommend FI or what?

Earthing system was TT. Zs - 9.75ohms
Also there was quite a bit of original stranded copper in the circuit.

Thanks

 

[brianmoooore]

some old 2.5/1.0 T&E in the circuit?

 

[aliensbrains]

That was one thought. Didn't actually spot it myself but obviously that would make sense. There was a fair bit of stranded 2.5mm but think the CPC was 1.5 in that.

Either way, what is best way to approach to meiw cert.

 

[westward10]

What reading did you get?

 

[aliensbrains]

What reading did you get?

1.32

(Was expecting 1.1ish)

 

[westward10]

I would be looking for some 1.0 cpcs.

 

[freddo]

There was a fair bit of stranded 2.5mm but think the CPC was 1.5 in that.

That 'stranded 2.5mm' was probably imperial 7/.029 which is about 2.9mm2. Which might account for expected readings being different.