RCD trips

[Jevban]

​

Hello
Elderly woman here, read lots of forums like this looking for advice but currently none the wiser,!
I had Led PIR lights installed recently, replacing old pir security lights and an old decorative light at the front door all using the original wiring. An electrician did the work. The lights run off my upstairs light circuit re the security lights...the front door light is via a switch by the front door. Electrician told me he found two wires, earth's in the old lights, not connected, so connected them. That night, my RCD, central in my fusebox, supposedly not protecting the side the light circuit is on, tripped. It had rained. Since then, the RCD trips constantly. The electrician who changed the lights came out , disconnected the wires from the one light, but left the others, saying it's not his work that caused the fault and to find another spark. Another lad came, did some remedial work in the house and left. That night, the RCD tripped again. The second spark returned and worked really hard and totally professionally, testing every time he did any, all over 2 days, finding numerous faults using a multi meter and additionally undoing all my sockets finding loose earths and broken sockets. All dealt with.
2.5 days later, as in last night, it rained overnight and I got up to no electricity again . He tells me that as the fault seems to be N to E, that a new CU with RCBOs will show more easily where the fault is. He is not giving me any hard sell re the CU by the way, but..It rained today..I'm home, no RCD trip. I'm many hundreds of pounds down presently and looking at getting the upgraded CU but with an honest opinion from the spark that there's no guarantee this will cure the problem. Sorry for the very long story, but does anyone have any ideas what may be wrong,?
Thanks
Jan

 

[James]

The clue is that when it rains, you have an rcd that trips.
somewhere you have water getting into the electrics and causing it to trip.

If you have a N to E fault, this is something that can be found by a competent electrician.

just to add a little bit of confusion though, I have known a N to E fault in the next door property to cause tripping in a property.

Edit, sorry for the short response but i have just been told my dinner is ready!!

 

[brianmoooore]

Changing the CU for a RCBO one won't do anything towards curing the fault, but it will greatly reduce the inconvenience when the fault occurs, since just the one circuit will turn off, and, of course will narrow down the fault to that circuit.
If it's definitely rain related, then moisture is finding its way into an outdoor fitting or an outdoor damaged cable. If the earth wires in these circuits were previously unconnected, the fault may have existed before the recent work, but went undetected because the fault current was unable to flow to earth along them.

 

[Jevban]

The clue is that when it rains, you have an rcd that trips.
somewhere you have water getting into the electrics and causing it to trip.

If you have a N to E fault, this is something that can be found by a competent electrician.

just to add a little bit of confusion though, I have known a N to E fault in the next door property to cause tripping in a property.

Edit, sorry for the short response but i have just been told my dinner is ready!!

Thanks James
The new lights aren't linked to the RCD but...I'm told it might be a borrowed live/ cable etc
Also...veru interestingly, linked to your comment , I had problems years ago associated with the semi detached house I'm linked to...he is a DIY bodge man...not approachable...

 

[Jevban]

Thanks James
The new lights aren't linked to the RCD but...I'm told it might be a borrowed live/ cable etc
Also...veru interestingly, linked to your comment , I had problems years ago associated with the semi detached house I'm linked to...he is a DIY bodge man...not approachable...

The clue is that when it rains, you have an rcd that trips.
somewhere you have water getting into the electrics and causing it to trip.

If you have a N to E fault, this is something that can be found by a competent electrician.

just to add a little bit of confusion though, I have known a N to E fault in the next door property to cause tripping in a property.

Edit, sorry for the short response but i have just been told my dinner is ready!!

The link to the rain is my thinking...but I'm being told that can't be the problem as the new lights are via my upstairs lights that are to the left of the RCD and therefore not protected by it.

 

[Jevban]

Changing the CU for a RCBO one won't do anything towards curing the fault, but it will greatly reduce the inconvenience when the fault occurs, since just the one circuit will turn off, and, of course will narrow down the fault to that circuit.
If it's definitely rain related, then moisture is finding its way into an outdoor fitting or an outdoor damaged cable. If the earth wires in these circuits were previously unconnected, the fault may have existed before the recent work, but went undetected because the fault current was unable to flow to earth along them.

Thanks Brian...very worrying if it's a pre existing fault only now found...I'm elderly, on my own and very OCD re my roof, damp course, electric, gas and water and always seek help if any problems with any of these
Thanks again.
Jan

 

[brianmoooore]

the new lights are via my upstairs lights that are to the left of the RCD and therefore not protected by it.

Not protected by any RCD?

 

[littlespark]

Can we see a photo of the layout of the consumer unit? It might be that some rcbo’s can be added without replacing the entire board.


Upstairs lights can be affected by roof leaks. Has anyone been in the attic to check?

 

[davesparks]

In my opinion replacing the consumer unit and waiting to see which RCBO trips is not a good fault finding technique.

If the lighting circuit which has recently been worked on is not connected to the RCD then it is very unlikely to be the cause of the tripping.

However it may be that a circuit connected to the RCD has been disturbed or damaged whilst the work on the lighting circuit was carried out. For example they may have damaged a cable in a wall when drilling into the wall.

From the original post it does sound like the first electrician was keen to get away and not interested in finding the problem.