Ceiling rose connection tripping MCB?

ls_diy · Nov 8, 2023

Hi guys,

I have recently encountered that my circuit breaker for the upstairs lights keeps tripping. I flick it back on and immediately it trips off again. I think the issue is coming from the bathroom light. So I have had a look at the ceiling rose and the picture shows what is going on. Note that this picture was taken after I removed the wires connecting to the light (these filled the far left and far right holes), and that's all I changed.

My main question is, from this diagram, can anyone tell me if there is an issue? And if not here, where else I should investigate? Another couple of questions/points...

1/. There appears to be three live and neutral cables (one each for the in, out and switch???) but there only appears to be two earth wires? Could this possibly be the source of the trip?
2/. The labelling "N", "L", "LOOP" seems strange (I may be ignorant though) since I thought the LOOP should contain three connection holes?
3/. There is a double wire in the first hole of the two-hole set labelled LOOP. I take it that the neutral (black) wire is essentially the switches "live" wire, but the red live wire, I am unsure about. I do have an extractor fan in the bathroom too and from what I have read of ceiling rose connections (e.g. diagram 3A of Looped-in lighting wiring - the ceiling rose - https://www.practicaldiy.com/electrics/lighting-wiring/light-wiring-loop.php), they sometimes double these wires up like this. But since all of the upstairs lights go off, I figured that there should be a "out" cable too.
4/. After replacing the hanging light cable with a new one, and flipping the breaker back on, all of the upstairs lights briefly turn on --- aside from the bathroom one! However, the breaker tripped a little while after and now all lights stay off again.
5/. I checked with a multi-meter and I do not appear to be getting any voltage from any of the wires, even when the breaker is flipped on. Have checked a normal working kettle lead from an outlet and get ~240V, so the multi-meter works.

Apologies for any abuse of wording and misunderstanding, and thanks for your help in advance!

littlespark · Nov 9, 2023

Just really untidy, and badly designed ceiling rose.

The "loop" terminal should be in the middle, with 3 holes, as standard with every other make of ceiling rose.

This bathroom must be the last light on the circuit, as there is only one feed coming in... its not going out to another light.
There is a live and switchwire going down to the switch and back up.... and there's a switchwire/ neutral going out to the fan.

as far as i can see, its connected in the right places, but just needs tidied up. The missing earth wire needs found and brought through and connected, as well as all of them being sleeved in gree/yellow.

The black switch wire from the switch also needs a bit of red or brown sleeving or tape just to identify it as a line conductor to avoid confusion.

The cables look a bit squashed, so i wonder if the problem is something pressing against the earth terminal there, or the problem could be with the fan, rather than here.

ls_diy · Nov 9, 2023

littlespark said:
Just really untidy, and badly designed ceiling rose.

The "loop" terminal should be in the middle, with 3 holes, as standard with every other make of ceiling rose.

This bathroom must be the last light on the circuit, as there is only one feed coming in... its not going out to another light.
There is a live and switchwire going down to the switch and back up.... and there's a switchwire/ neutral going out to the fan.

as far as i can see, its connected in the right places, but just needs tidied up. The missing earth wire needs found and brought through and connected, as well as all of them being sleeved in gree/yellow.

The black switch wire from the switch also needs a bit of red or brown sleeving or tape just to identify it as a line conductor to avoid confusion.

The cables look a bit squashed, so i wonder if the problem is something pressing against the earth terminal there, or the problem could be with the fan, rather than here.

Thanks very much for the reply and the explanation, especially about the bathroom light being the last on the circuit. Yes the lack of third earth wire and sleeving (and red tag on the black switch wire) was definitely concerning. I plan on taking out all the wires to find the missing earth, connect it and check they are not pressing against anything. As for the fan, it does actually have a separate 13 amp fuse panel. I have replaced that fuse, but maybe I should look at the connections there too. If I make any progress I will update the post. Thanks again.

DPG · Nov 9, 2023

ls_diy said:
Thanks very much for the reply and the explanation, especially about the bathroom light being the last on the circuit. Yes the lack of third earth wire and sleeving (and red tag on the black switch wire) was definitely concerning. I plan on taking out all the wires to find the missing earth, connect it and check they are not pressing against anything. As for the fan, it does actually have a separate 13 amp fuse panel. I have replaced that fuse, but maybe I should look at the connections there too. If I make any progress I will update the post. Thanks again.

Make sure it is a 3A fuse that is fitted.

ls_diy · Nov 9, 2023

Hi guys,

So I took the wires out and rose attachment off. As much as I tried, there was no sign of the other earth wire. I didn't want to try and pull it through via the other wires, as I don't know what's going on above. I also changed the 13 amp for a 3 amp, thanks. No change unforunately, the lights are all still off with the breaker flipped on or off. I volt-checked ceiling wires and extractor connection wires with the breaker on, and they both read 0 volts between earth and live, so I don't really know what's going on.
We know an electrician so I think its time to ask him.

Thanks for the input and if we do sort it, I'll report back with the cause/solution.

ls_diy · Nov 20, 2023

Just thought I would give an update. Had an electrician friend and another recommended electrician round. They both seem to think there must be a break in the wire running from the fuse box to the upstairs lights as the bathroom is receiving no power. Looks like they are going to have to run a new one to the loft. If that is the case, does anyone know approximately how much a job like that would cost? Just to give me a general idea as I shop around for quotes. Cheers.

DPG · Nov 20, 2023

ls_diy said:
Just thought I would give an update. Had an electrician friend and another recommended electrician round. They both seem to think there must be a break in the wire running from the fuse box to the upstairs lights as the bathroom is receiving no power. Looks like they are going to have to run a new one to the loft. If that is the case, does anyone know approximately how much a job like that would cost? Just to give me a general idea as I shop around for quotes. Cheers.

Impossible to say without seeing it. See if the quotes from these two electricians are similar and take it from there.