low ir

[sima24]

Hi guys can anyone give any ideas on these low readings i have. On both rings im getting 0.7 / 0.8 ohms across everything, triple checked everything is unplugged, a pretty new installation, all other tests fine, im ripping my hair out

 

[Hiddo]

Have you checked all the screw terminals behind sockets etc?

 

[sima24]

Yes checked all sockets also continuity readings all around 0.33 ohms

 

[AndyL]

Split the ring in half and test as 2 radials, this will tell you where the fault is, you can then break it down further to find the exact point

 

[Hiddo]

And your getting the same low reading on both RFC's? I reckon it's time to split the rings. I had one the other day where I ended up testing between each socket to eventually find a cable that had been pulled through a joist so badly the insulation had been dragged off. Admittedly this wasn't on both circuits!!

Split one ring mid point ish and IR test it again.

Just another point, are you sure you have got the right ends for both rings??

 

[SYKRAPS]

Do you have the MS and RCD's turned off, and if it is RCBO's have you disconnected the fly leads to perform the dead tests?

 

[sima24]

Cheers,
My readings so far
Upstairs ring
L-N 0.8
L-E 2.8
N-E 2.7

Downstairs ring
L-N 0.00
L-E 1.05
N-E 1.06

 

[sima24]

Yep ms off both rcds off

 

[AndyL]

Cheers,
My readings so far
Upstairs ring
L-N 0.8
L-E 2.8
N-E 2.7

Downstairs ring
L-N 0.00
L-E 1.05
N-E 1.06

you need to change the range to get an accurate reading for downstairs L-N, but it looks like a load is still connected to the circuit

 

[tony mc]

Cheers,
My readings so far
Upstairs ring
L-N 0.8
L-E 2.8
N-E 2.7

Downstairs ring
L-N 0.00
L-E 1.05
N-E 1.06

Are you talking about Meg ohms here.

 

[Octopus]

Do you still have wet plaster??

 

[frank3323]

if its on both rings and the rings are def correct first thing i would do is disconnect from DB all together, and split each ring, only work on one at a time, part of the ring must be clear, work back from the centre, if its not the plaster, not the RCBO / RCD and its still showing fault, remove 2 socket faces, test the link in-between, and repeat for next link, etc etc

 

[sima24]

Thanks, no wet plaster, house was built about 7-10 years ago. Things im thinking are neon switched spurs, bell transformer etc.

 

[DaveyD]

Hi. I realise on your opening list you said you did this but.... Worth checking again. All double pole fcu off and everything unplugged? What about the non switched fcu's they are single pole so remove fuse and link out the neutrals. Tv amp in loft off of rfc ?

 

[Octopus]

Outside lights, spur to garage, the list goes on. But with those readings I'd put money on things still being connected to the circuits