Domestics...

[SUNRAY]

Yesterday Missus Sunray and I went visiting friends. While there the power tripped, simply tripped while the 4 of us were sitting chatting.
It turned out to be a N-E problem (~400KΩ using a multimeter) on the downstairs lights, second fitting opened being a plug-in ceiling rose of this sort of design:

to reveal this:

Earth wiring not shown for clarity.

I took photos but it's far too conjested to see what's there. Seeing the yellows and blues my initial thought being the 2 way switching is teed there but it's not the case.

To say it is tight for space is an understatement.

It appears to be a conventional loop-in at the rose with the addition of a couple of 3c&e, we have no idea where they go but for now one has been disconnected to isolate the fault which is currently assumed to be a cable fault pending further investigation.

They went off this morning for their ruby wedding celebration of returning to their honeymoon hotel. This will have to wait until they return home. The lucky thing is the fridge freezer is on the same RCD.

 

[sparkwright]

Not quite why they did all of this.

Don't imagine there's two timed extractor fans in the room!
Or some form of emergency lighting.

Are there two additional lights in that room, which in turn, are permanently feeding something else?

Someone has gone to a lot of trouble.

Does it look like a professional install?

 

[ebee]

Just a quick tip.
If you find a 3C+E in a ceiling rose it could be one of these reasons.

A supply to a 3 pole fan isolator .

Ditto to an emergency light.


An unusual way of providing two way switching - if we call the connections to a switch COM, L1 & L2 then a "normal" two way switching arrangement might be a T & E between L1 & L2 of the first switch then 3C & E between the first switch and the second switch, that is pretty usual really, however it is not unknown for someone to run 3C & E from each of the two switches to the rose itself, this negates the need for a T & E from one of the switches but means another connector (a strip connector or a wago for example ) inside the rose connectinng COM to COM on both switches.

There are other unusual arrangements possible in lighting circuits too but I will avoid making it overcomplicated.

There are three pretty standard basic ways when it comes to connecting lighting to switches but there can be a mixture or hybrid of 2 or 3 of them too.

 

[Murdochcat]

I would be looking at the lights in the adjacent rooms to see if the connections are similar or offer up any clues

 

[ericmark]

I have had it with the slide in ceiling rose shown, where I have had a poor contact, caused by the plaster not allowing the cover to sit fully home.

 

[SUNRAY]

Not quite why they did all of this.

Don't imagine there's two timed extractor fans in the room!

Just a quick tip.
If you find a 3C+E in a ceiling rose it could be one of these reasons.

A supply to a 3 pole fan isolator .

no none

Or some form of emergency lighting.

Ditto to an emergency light.

no, none

Are there two additional lights in that room, which in turn, are permanently feeding something else?

no

Someone has gone to a lot of trouble.

Does it look like a professional install?

Hard to tell as there is so much in there it is literally crammed into place

An unusual way of providing two way switching - if we call the connections to a switch COM, L1 & L2 then a "normal" two way switching arrangement might be a T & E between L1 & L2 of the first switch then 3C & E between the first switch and the second switch, that is pretty usual really, however it is not unknown for someone to run 3C & E from each of the two switches to the rose itself, this negates the need for a T & E from one of the switches but means another connector (a strip connector or a wago for example ) inside the rose connectinng COM to COM on both switches.

I've come across that several times and used it myself fairly recently when I discovered the trend of providing 3C&E for switchdrops in some new-builds (in case a neutral is required). This one from 2009 used the earth terminal as the junction until some later work added earth wires to it. The yellow is just visible to the left of the earth sleeve.

There is 2 way switching but it is conventional method with a choc bloc at a switch. (I changed switches for them at redecoration).

I won't be doing anything further until they return from holiday.

 

[SUNRAY]

I would be looking at the lights in the adjacent rooms to see if the connections are similar or offer up any clues

I looked at one during faltfinding which is totally normal 3 T&E loop-in.

 

[sparkwright]

Could some movement sensors have been added?

 

[SUNRAY]

I have had it with the slide in ceiling rose shown, where I have had a poor contact, caused by the plaster not allowing the cover to sit fully home.

It doesn't seem to be an issue here, isolating that 3c&e proves there is ~400KΩ between blue and earth on the cable, red and yellow appear to have nothing (All measured with high impedance multimeter.

 

[SUNRAY]

Could some movement sensors have been added?

Nothing has been done since they purchased the house other than changing accessories pre Covid.

 

[sparkwright]

Nothing has been done since they purchased the house other than changing accessories pre Covid.

Ok, could some movement sensors have been installed originally?

Couldn't resist it.

 

[SUNRAY]

Ok, could some movement sensors have been installed originally?

Couldn't resist it.

That's always possible. I've been working on the basis there is something unidentified hanging on the end of these, redundant works too.

I won't be back there for at least 2 weeks unti they return from holiday.

 

[sparkwright]

Is this the hall/landing? Or a just a room?

 

[SUNRAY]

Is this the hall/landing? Or a just a room?

Just the lounge with switches at the internal door and patio door.

 

[ericmark]

I remember looking at a compressor, using my multi-meter on ohms, and reading seemed OK, but returned with my mega and it showed short circuit. If multi-meter not showing infinity, then likely a fault.

If you had not showed the switch drop, I would have said three core used for that, but three core and earth only really used if emergency lighting or fans.