very strange

what do u think of this one.....

Installed new ring circuit only 6 skts and aprox 35m end to end. anyway testing cables before connection and come to i/resistance. 500v L-E varying reading between 10-15 MOhms. very strange i thought so went round removing all sockets and testing legs between skts. all clear. Great so connect sockets back up but leave hanging. test again all clear. now i start to fix back the sockets one at a time. every time i fix one back i perform i/r test. for every socket i fix back the reading gets lower and lower. so skt 1 fixed back and reading of 91mohms. 2nd skt screwed back and test again 83mohms and so on. last skt screwed back an i/r value is now 10.3 mohms L-E!!??

what on earth could be happening? no cables are dammaged and the boxes are dry lining and therefore plastic. when connected into the board keeps taking out rcd.

tried i/r readings across all skt terminals too whilst disconnected. all fine.

can anyone think of any possible reason why this could happen?

headbang

you haven't got anything plugged in, or something existing spurred of the circuit? Left the cable outside? You've probably already checked all this though.

Could try a plug in adapter and test between the socket terminals there?

10.3megohm shouldn't trip the rcd though.

edit* didn't noticed you said when fixing back!

are the boxes deep enough and not squashing the cables? not catching them with the m3.5? Grommets all in place?

you haven't got anything plugged in, or something existing spurred of the circuit? Left the cable outside? You've probably already checked all this though. Could try a plug in adapter and test between the socket terminals there?

10.3megohm shouldn't trip the rcd though.

edit* didn't noticed you said when fixing back!

are the boxes deep enough and not squashing the cables? not catching them with the m3.5? Grommets all in place?

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no ive checked all the usual ones. plastic dry lining boxes so no gromits or contact with screws. if i removed them again now all the cables are un damaged and neatly folded into boxes. only other thing i can think of is that the sockets are faulty and as i tighten them up to the wall, something inside the socket is flexing and causing the breakdown in insulation of conductors. highly unlikley i know but there seems to be no other explanation

Is it newly plastered???

If so then it's just a bit of damp

What make are he sockets ?

Is it newly plastered???If so then it's just a bit of damp

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was plastered two weeks ago, its certainly not damp and if it was i cant see how this would result in the readings im getting

What make are he sockets ?

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CED decorative brushed nikel jobbies http://www.ced-elec.co.uk/catalogue/departments/default.asp?sid=1&dpid=5

hadnt come across them before and was sllightly reluctant to fit them after they were customer supplied and the quality didnt seem amazing

Unless there is heating then the plaster will not have fully dried out... (not in this weather!)

Unless there is heating then the plaster will not have fully dried out... (not in this weather!)

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but if there is no contact between terminals, cable or plaster than how could this be? the socket rears are completly enclosed within the box mounted in the wall

have u tried ir test on sockets?connect short length of brown blue & earth to socket bare ends apply probes L-N switch on tester and gently flex socket then do L-E N-E.if nothing else u can rule out doddgy socket theory.

rubbish sockets or rubbish cable

did a rewire earlier this year 40m for a ring cct 8 sockets 100 Meg

thought this was crap so connector blocked all sockets 250 Meg

phoned wholesaler say cable was crap,,,,,,,,,yes we know he said they have just gone bust

still within regs cheers easy

have u tried ir test on sockets?connect short length of brown blue & earth to socket bare ends apply probes L-N switch on tester and gently flex socket then do L-E N-E.if nothing else u can rule out doddgy socket theory.

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not yet no hadnt got time. this was at 6.30 pm this eve and im full of cold and wanted to get home. thats my next job but wouldnt imagine this to be the problem with all of them. im normally very good at fault fining but this has baffled me

rubbish sockets or rubbish cabledid a rewire earlier this year 40m for a ring cct 8 sockets 100 Meg

thought this was crap so connector blocked all sockets 250 Meg

phoned wholesaler say cable was crap,,,,,,,,,yes we know he said they have just gone bust

still within regs cheers easy

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no cable was pirelli and meters out fine all connected up but socket faces not screwed back. only when i screw back do i start getting problems. im thinking poor quality skts but surely they coulnt produce and sell something this bad. the i/r reading doesnt say still but is constantly changing

It doesn't take much...

After walls are plastered you will see that the KO boxes get quite damp.. the boxes are cold and the moisture condenses on them!!

Something similar,,,

I was called to a RCD tripping and not resetting.. I found the fault pretty quickly.. The air in the house was very humid and when we unplugged the washing machine the fault cleared.. the offending socket was behind the machine on an outside wall which was tiled (and soaking).. but there was only a tiny amount of moisture tracking between the socket pins.

It doesn't take much...After walls are plastered you will see that the KO boxes get quite damp.. the boxes are cold and the moisture condenses on them!!

Something similar,,,

I was called to a RCD tripping and not resetting.. I found the fault pretty quickly.. The air in the house was very humid and when we unplugged the washing machine the fault cleared.. the offending socket was behind the machine on an outside wall which was tiled (and soaking).. but there was only a tiny amount of moisture tracking between the socket pins.

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i appreciate what your saying but on this occasion this is not the case. the place is bone dry

with dry lining boxes you have to be careful the stripped singles don't go back through and out of the box,

There may be some damp insulation in the cavity its touching?

with dry lining boxes you have to be careful the stripped singles don't go back through and out of the box,There may be some damp insulation in the cavity its touching?

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trust me this stuff is installed a1 and they are internal stud walls. the installation is immaculate

Just firing ideas at you mate.

try putting a hairdryer on the sockets and meggering again see if theres any change. Its either the cable or the sockets IMHO.

take a good quality socket or two of your own to try