interconnections on ring how to carry on

GLENNSPARK · Oct 29, 2012

domn said:
no its all twin t+e (what i can see ) ill be doing the r1r2 at all points tomorrow i was just starting this when the lad showed me the 1mm so i got rid of that first .
if im right on the lower cpc do i need to put this on cert ?

what you doin here?...an EICR?...if so then just make sure it meets disconnection times....
you`v got 2 choices
you get an R1 R2 (recommended here) on every point of the ring....or you go with the end to end resistances obtained and get your points on a Zs...all of em...that would be the easier way....
summats not rite though....
if it meets disconnection times then go with it....
how old`s the install (estimated)?...
any signs of alterations/additions?
RCD`d?
just be on the lookout for stuff won`t you...as if this is giving back the values you have described then there may be other `nastys/anomalies` lurkin....

dagrat · Oct 30, 2012

Both the R1 and Rn readings equate to just under 50m in length and the R1+ R2 is appropriate to these readings. It's the R2 reading that is lower than expected, but this is very common on existing installations. Unless I'm missing something

SPARTYKUS · Oct 30, 2012

Here's an idea- discon. all the other cpc's and check r2 again?

Its almost as if there's a section of the ring with a 10mm bond to a pipe & another bond to the same pipe from another point in the ring

Guest55 · Oct 30, 2012

its threads like these that remind me why i favour radials these days.
lifes too short to waste it on endless continuity tests lol.
;-)

Badged01 · Oct 30, 2012

Sounds like old wiring in a property that has been subject to DIYing. On the face of it the Live and Neutral seem OK but do an R1/R2 to confirm as Glen says that you have a continous earth path. If you do have an earth path Id be tempted to open up each socket and look at the wiring configuration ---time consuming I know. You've got a parallel earth path in there somewhere reducing the value. If there arent any obvious additional wires then it may be as Sparty says, you have a path somewhere junctioned off the CPC thats lowering the resistance. Be interesting to know if you eventually track down the root cause to the CPC or something on the live/neutral!!

And Biff your right ....... a lot of continuity testing & checking eating up valuable time!!