Strange RCD Fault

[Guest569]

80amp main switch RCD, occasionally trips when a couple of circuits are switched on (doesn't matter which circuits) with nothing plugged in.

IR tests all good. Replaced RCD for new. Happens in all weather ( don't think its external )

Only sockets on this consumer unit.

Ive had my guys out at it twice with no joy. New build wiring from 16th edition.

Im going to investigate myself this week, Im sure Ive had loose connections causing tripping before, it about all I can think of, a loose tail somewhere around the main switch.


Anything else to look out for ?

Im pretty certain its not a dodgy nail at floorboard etc its fairly new property and in good condition with chipboard throughout.

 

[Guest569]

and what model is the metrel tester ?

will check

 

[Guest569]

I think you have to get the circuit make up absolutely sure and precise
That is before even thinking about searching for the RCD tripping cause

I know you say you have tried and tested most of what you expect to be the cause,but personally I suspect you are getting bogged down sorting 2 different problems with one mind set

This is not meant to be criticism of your testing or yourself (because that would need to be observed rather than guessing procedures and outcomes on a forum)
It's meant more as a pointer, hopefully,that may make the road clearer for you
It seems to be a pain in the neck problem,but there is a reason and logic and testing and investigating using that logic will reveal all

Totally, There is 2 problems Im sure. Ill get circuits organised as best I can on Monday.

 

[Plonker 3]

Sorry only browsed over the thread so apologies if this has been asked already, but you say you have narrowed it down to a RFC. Have you removed every socket and proved each leg between the sockets? Then carried a IR on each individual leg?

 

[Guest569]

Sorry only browsed over the thread so apologies if this has been asked already, but you say you have narrowed it down to a RFC. Have you removed every socket and proved each leg between the sockets? Then carried a IR on each individual leg?

Yes and all fine. I wish it was that easy and one leg was down.

IR is fine and it bells out ok but Im convinced something is spurred off the ring then back onto it or onto another circuit somehow, Frankly I think someone has made a complete arse of wiring the ring !

 

[R G]

If your able to pop back before Monday , you could isolate that 1 circuit and see how it goes before Monday , to confirm your suspicions .

 

[jaypp]

was the 'floating live cable' in a position where movement, possibly caused by vibration from foot traffic etc, could cause the random tripping?

 

[Dcf]

i had a kitchen ring of 7 sockets last week with 3 faults on it.
knacked mcb due to them switching it on a l-e fault numerous times
no ring continuity on live and earth rings
traced it back to a burnt cable shoved in an inaccessible tank cupboard shorting between live and earth while the neutral was in one piece
all down to a previous young spark who was out of his depth leaving a bodge!
trying to work out some muppets idea of a ring circuit is frustrating at times

 

[Guest569]

was the 'floating live cable' in a position where movement, possibly caused by vibration from foot traffic etc, could cause the random tripping?

No tucked in a pretty cramped board.

 

[Plonker 3]

If you are going back with RCBOs and you suspect on particular circuit, surely a cheaper option and much easier way to confirm would be just to put the suspect circuit on a RCBO? What is the earthing system of the property?

 

[jackhammerJIM]

what do you mean by belling it out ?????????????????

 

[R G]

what do you mean by belling it out ?????????????????[/QUOTE





CONTINUITY

 

[Des 56]

what do you mean by belling it out ?????????????????

What do you mean by what do you mean belling it out,know what I mean

 

[Plonker 3]

know what I mean

Harry?

 

[telectrix]

belling out.

http://www.google.co.uk/url?sa=t&rc...9wyk46YyEd5YbOO5NT0tdEg&bvm=bv.62286460,d.ZGU

 

[jackhammerJIM]

so JRC you are saying it bells out for continuity but you have no end to end continuity .

how can this be ?

i know wat i mean des and i know what you mean if you know what i mean .

- - - Updated - - -

So thats what he's been doing tel .

no wonder he hasn't found it .