Renovated house low r2 readings !

[Soulsurfer]

Just been sorting out a right mess during a house renovation and tests on newly installed ring final are r1 0.35
rn 0.35 & r2 was expecting around 0.58 but had consistently 0.00 Ohms.
MFT was zeroed again from scratch and was still giving a zero resistance reading
Almost all cable is new and IR tests all perfect. Any ideas ? Thanks

 

[The Ghost]

Sounds like the earth has shorted on the beginning run of the cable as you had 0.35 on rn/r1 must be the earth ring is so short it reads 0.00 does your tester go to three figures? Have you tested at the middle socket? r2? end to end that would indicate if that was the case.

 

[Soulsurfer]

Back there Friday to finish up so I'll check more extensively then, closest socket to board 0.09 ohms which is very close to the board. Is a really small ring too. Cheers
Tested R1 +R2, and R1 to RN too etc to check all. Yes tester goes to 3 figures is Fluke 1653B

 

[westward10]

Cpcs aren't jointed together in the board? Try testing at a socket.

 

[drzsta]

Something on the ring has a parallel earth paths? How water heater etc..

 

[Soulsurfer]

Was testing at sockets with kewtech plug adaptor but wondering if the two croc clips I was using not connecting tight at board or similar.

 

[Soulsurfer]

Something on the ring has a parallel earth paths? How water heater etc..

Shouldn't be anything I can think of ! Weird one, immersion is seperate, all wired to their own rcbos in new cu

 

[westward10]

Well if you get zero ohms that is good contact.

 

[Soulsurfer]

Well if you get zero ohms that is good contact.

True but as said parallel path from somewhere as it's too good.

 

[Toneyz]

What position are you testing the ring from the consumer unit or socket ? I have had it in the past where had small ring and the dampness of plaster damp wall between the metal k.o. boxes have given a lower continuity reading than I should of had but not that low.

 

[Soulsurfer]

What position are you testing the ring from the consumer unit or socket ? I have had it in the past where had small ring and the dampness of plaster damp wall between the metal k.o. boxes have given a lower continuity reading than I should of had but not that low.

Tested at each socket on newly rewired small ring, as said expected around 0.58 and got 0.00! After 0.35 each on L's & N's cross connected.

 

[Soulsurfer]

Tested at each socket on newly rewired small ring, as said expected around 0.58 and got 0.00! After 0.35 each on L's & N's cross connected.

I'll find results in van in a bit and post up, just in case I've messed up here. r2 end to end was the 0.00 ohms at board sorry

 

[Ian1981]

Maybe cables have been jointed somewhere but cpcs have been connected together in one connection rather than connected in 2 separate connections.
But 0.00 ohms suggests that the cpc ends are crossed in the db with another circuit

 

[Soulsurfer]

So total tests so far :
r1 0.35
rn 0.35
r2 0.00 expected 0.58

R1+R2 0.22
R1 +RN 0.15
IR all >500M
Rcd
18.4 ms x1
28.4ms x5
Zs 0.52

 

[Toneyz]

Where are you doing this test from ?

 

[onions1066]

There isn't much it can be. Are you sure they aren't touching where they enter the board if the sleeving isn't pushed right up?

 

[Soulsurfer]

There isn't much it can be. Are you sure they aren't touching where they enter the board if the sleeving isn't pushed right up?

Going to have to check step by step I guess as it's a pain in the ....

 

[onions1066]

What's the heating fed from?

 

[Toneyz]

There isn't much it can be. Are you sure they aren't touching where they enter the board if the sleeving isn't pushed right up?

That's a good point forgot about the new metal boards

 

[Soulsurfer]

Where are you doing this test from ?

End to ends from board, R1+R2 at outlets all faceplates brand new Hager gear, Rcd tests at board of course, and Zs from R1+R2 result socket outlet ( furthest point )