RCD Tripping intermittently

Dal_Whinnie

bungle4by4 wrote: »

!!!!!! get your sparky to test the RCD and perform an insulation resistance test to ensure your wiring is actually ok.

As I said in my initial post, I have arranged that. My sparky has already checked RCD unit and checked the wiring on the kitchen lights. No problems. My question was basically, does anybody else have instances of lcd lights triggering the RCD. It doesn't really make sense to me that when (occasionally) I turn the lights on the power goes off but the lighting circuits don't.

zax47

Dal_Whinnie wrote: »

As I said in my initial post, I have arranged that. My sparky has already checked RCD unit and checked the wiring on the kitchen lights. No problems. My question was basically, does anybody else have instances of lcd lights triggering the RCD. It doesn't really make sense to me that when (occasionally) I turn the lights on the power goes off but the lighting circuits don't.

The under cupboard lights are probably wired via a "fused spur" from the socket circuit ("ring main") that's a perfectly normal and acceptable thing.

How old is your consumer unit ("fuse box")? Does you have 1 or 2 RCDs (The trip switch with the TEST button on) I'm guessing you've a single RCD protecting all the socket circuits, which is why you are confused that swtching on a light is tripping them.

Dal_Whinnie

zax47 wrote: »

How old is your consumer unit ("fuse box")? Does you have 1 or 2 RCDs (The trip switch with the TEST button on) .

I think the unit is about 5 years old. It has two banks of switches, one for the power sockets and one for the lighting circuits (and central heating). The bank with the power sockets has the test switch.

When the sparky came in last week he couldn't find any neutral going back from the lightswitch to any of the power circuits. A mystery but all I can do at this stage is await the full inspection.

tartanterra

Dal_Whinnie wrote: »

I think the unit is about 5 years old. It has two banks of switches, one for the power sockets and one for the lighting circuits (and central heating). The bank with the power sockets has the test switch.

When the sparky came in last week he couldn't find any neutral going back from the lightswitch to any of the power circuits. A mystery but all I can do at this stage is await the full inspection.

Not unusual.

Many people assume that the blue/black cable within lightswitches is a neutral.
In actual fact, very few lightswitches will contain a neutral cable within the switch backbox, as the blue/black cable is normally utilised as a switched live (and should have a brown sleeve to identify this, but many DIYers never do this).

Dal_Whinnie

Thought I would just let people know that we did eventually find the problem. We have GU10 halogen lights in the kitchen ceiling and it was one of the transformers for these that was on it's last legs. I needed to take up the carpet and floorboards in the bedroom above to get at it but have had no problem since replacing it.

mehera

Any electrician worth his salt would be able to find the fault within and hour.

Get someone else in as stated!

societys_child

mehera wrote: »

Any electrician worth his salt would be able to find the fault within and hour.

Get someone else in as stated!

Did you miss post 16? - over one and a half hours before you posted that!

Alias_Omega

The thread is over, the OP has been back to respond that it was a transformer.