low IR N-E

[sonobit]

Maybe a extractor fan some where, try knocking off MCBs one at a time and re testing might tell you where resistance is.

 

[wet string]

had a similar problem on a pir recently, r1 and rn ok tho, thats probably a loose connection, had a lower ir on n-e but well within spec so didnt pay too much heed, untill i connected the new rcd cu, then the ring circuit tripped, remeasured and found short n-e which was not apparent at first test, so socket plates off, break ring and retest ir in sections, during this found a small nick in neg insulation, which i repaired, problem solved. the nick was so positioned as to be out of sight at first glance and was bearing against the backbox in varying amount when socket plate tightened, trapped neg to plate screw would give same fault, the act of plugging in and unplugging could vary the ir or even give an intermitttent short. really bad news is ,couldnt really charge the client for all the faffing about to find it,

 

[sivoodoo]

Cheers everyone the client wants a rewire now, yipee. That saves a whole load of crawling about for (no swearing) all!