Lights not on RCD, but still trip it??

[TPES]

Its a split load board (16th), lighting on main switch, most other circuits on RCD as expected, every so often the rcd trips out when the light dimmer switch in the lounge is pressed, I thought it's was a coincedance at first but it's happened 4 times now everytime the light is switched on. No tests done as of yet, I'll be getting on it soon, I'm guessing there's some kind of leakage somewhere, I've never had a circuit trip an RCD when it's not even protected by it,

What ya reckon?

 

[electricAl]

Hia Curt

Reckon there`s every chance you find somekind of borrowing of neutrals
Is there just one lighting circuit?

 

[Guest123]

Also....make sure the split-load kit is connected correctly and the neutrals aren't damaged in any way.

 

[TPES]

There's 2 lighting circuits, both on main switch. Customer says been fine for years. Board hasn't been touched. I suppose it could be a damaged neutral.

 

[SirKit Breaker]

Dont overlook the RCD, give it a ramp test if you can.

 

[fog]

just a stab in the dark
is the neutral wire rubbing against another where it comes into board? can be difficult to see
what if the dimmer is removed?

 

[Jason Smith]

As above mate, circuits been fine for years says the customer, but has he put a nail through the earth and neutral anywhere ?

Well its gotta be a visual all over the suspect circuit, then IR all the legs, with everything disconnected. If its lighting, the lighting points are very usefull for wrapping metal tinsel around..............christmas wernt long ago !!!

 

[bugsy]

Is an old dimmer switch, I have had a simular incident , tested N/E . ramp tested RCD all O.K. - changed dimmer fault disappeard - and no I don;t know!

 

[Jason Smith]

Dimmers work i believe on switching the current on and off quickly, the effect being that over a period oftime ,less power gets to the light. simple test is to by pass the dimmer switch join up the wires, and see if the fault clears.

 

[yido81]

this very interesting, i had exactly the same prob in november last year, it was the upstairs lights on the non rcd side, tripping the poxy rcd !! tried everything, all tests, took everything apart, you name it i did it!! it just so happens the customer wanted there bathroom light changed, so i did!! and hey presto, the bloody fault dissapered, they never had a prob since!!

 

[wattsup]

99.9% its a neutral fault

 

[rumple2009]

this sounds like the neutral has been nicked and is linked to the dimmer switch . turn the dimmer on and turn the house lights on one by one most likely you find its nicked from the landing light which is on the other main switch. thats what i found when i had that problem

 

[mr browned off]

I dont sppose there is any chace of it being anything to do with parallel earth paths is there? ie the problem being elsewhere and not on that circuit ? Tell me if i'm sounding ridiculous !