lighting circuit problems

[glasgospark]

upgraded board to dual rcd
everything ok
that night lighting circuit breaker trips rcd stays on
i go back try putting breaker back on trips after a couple minutes , every light in house working when breaker on
tried disconnecting all outside lights etc, also still tripped with every light switch in off position ,
after numerous attempts trying different things the rcd then tripped along with the mcb , now rcd wont stay on when lighting mcb is on everything else in house is ok , i have tried a different mcb for lighting and still happens , it also stayed on for 4 hours yesterday untill ittripped that night ,

no timers on circuit or anything

any thoughts

 

[telectrix]

trapped behind heating pipe. like it. blame wet-pants then. LOL.

 

[Dubbo]

Ps , method used was Breaking down circuit and I.r between every point

Is there another method?

 

[Guitarist]

Is there another method?

There's always the "ask on the forum till you get an answer you like" method....

 

[telectrix]

or keep flicking the MCB on and on till it clears the short.

 

[i=p/u]

Or stay at yours , not a chance your lights will ever fail.. Yes u

 

[Englishman]

Sorry guys been M.i.a

been an on going job here customer only ever available now n then for around a hour ,
Found fault which was on the loop feed cable going between the 4th-5th switch , still haven't rewired it yet will be doing so next week , I'm thinking rodent or trapped along side heating pipe at boiler

Had a similar fault and situation a few months ago, could only ever spend an hour or so at the property, never ideal. Also, was never really a fault when I was there, was getting a 70meg IR and nothing lower, once it was in use for a few hours though it was then tripping, and found a multitude of small faults with nicked insulation, loose earths, loose connections, even an earth being used as a neutral link!

Was a squashed cable on top of a central heating pipe in the end, would have been solved a lot quicker and cheaper for them if they'd have told me the truth when I asked if they'd ever had a flood. Was being squashed more and more every time anyone walked along the upstairs passageway.

 

[glasgospark]

Never managed to strip the faulty cable out as it was in accessible , but we renewed it and all ok now