Lights circuit trips every few days

Brussels Sprout

I have a single circuit that has 5 lights on it. 3 of them are normal lights. 2 of them are dimmers.

Every few days this circuit will trip - usually overnight, when all 5 lights are switched off.

If I reset the trip switch by clicking it upwards at the fuse box it instantly jumps back down again.

However, if I remove the light bulbs from the 2 dimmers and then try resetting the trip switch it does not instantly trip again and the 3 remaining bulbs work when turned on.

If I then put the dimmer bulbs that I removed, back in, they work too.

Three or four days later though the whole thing happens again.

Does anyone have any idea what might be happening here?

10-10-20

Sounds like you have two (maybe interlinked) issues there: a nuisance trip and an in-rush current problem.

In-rush current issues are commonly design problems with cheaper bulbs where the voltage-dropper capacitor in each bulb takes a large start-up current - and by virtue of having multiple bulbs, exceeds the rating of the breaker causing it to pop.

Can I ask a few questions: Are the dimmers definitely switched off when you remove these two bulbs to recover the breaker? And does the breaker trip overnight if the same two LED's are removed? Are you getting power disconnections overnight by any chance?

Brussels Sprout

https://www.boards.ie/discussion/comment/119668360#Comment_119668360

Thank you for the response.

 Are the dimmers definitely switched off when you remove these two bulbs to recover the breaker?

They are both controlled by a single dimmer switch. That switch is both a button and a dial. If you push the button it switches the lights on/off. When you switch them on you can dim by twisting the button. I have that button in the off position overnight. If I push that and it doesn't come on in the morning (due to the tripped switch) I push it to the off position again before proceeding.

And does the breaker trip overnight if the same two LED's are removed?

I don't know, I haven't tried that. It's a bit of hassle removing and inserting them so when they're working I leave them alone

Are you getting power disconnections overnight by any chance?

I don't know that either. I don't have any electrical clocks plugged in that would tell me that that has happened.

Here are the two bulbs if that helps

Both are the same type. That code on the bottom line is SC526571

kirk.

Hard to fathom what's going on there

Is it an RCBO that's tripping have u a pic of breaker

Might be an IR test needed if it is indeed only the 5 lights on circuit?

whizbang

Any outside lights - security PIR, timer etc. Check if they are on the same circuit.

I would check the dimmer next. swap it for a simple switch for a while. Any earth or Neutral wires at the switch points ?

A random question- whats the last thing to be switched off at night? or switched on..?

I suspect those old school incandescent lamps are still there because LEDs wouldnt work with the dimmer..

DublinDilbert

I would check any external fittings that might be on the lighting circuit or junction boxes etc for water ingress. The last phantom tripping I had like this on a lighting circuit was caused by a slug getting into a junction box for an exterior light. After quite a few trips, I eventually opened up the junction box and found him in the lid of the box. He was lying across the L/N connections, but was still alive and made his way back into the garden.

Motion activated exterior lights are often powered 24/7, so can often cause this sort of thing.

kirk.

Good points on the external lights

Took me a while to realize that one

Always easier to fault find when it's present