UK domestic lighting circuit. - What the........

[davelittlewood]

About me.
Fastidious about wiring.
Degree in Mechanical Engineering, extremely good spanner monkey (rebuilt engines, gear boxes).
BUT I know my limits and what I am allowed to do according to Part P of the UK building regs etc.

Just been in the loft to do some tidying and found a right rats nest of the upstairs lighting.

It does not look like a typical domestic radial circuit, more Iike 1 feed from the CU and then a great big chocolate block connector that then feeds multiple radials in parallel.
The cables are not clipped to the rafters and most are buried under the insulation (I doubt that the blokes from EON thought about the need to consider the current rating when then cable is buried in insulation).
I was trying to tidy up the cables ready to actually clip them to the beams so that I'm not going to trip on one as I'm clambering about and found this massive clump of about 6 cables going into a massive bundle all wrapped up in electrical tape.

Has any one seen a circuit that splits out like this?

I'll rig up some festoon lighting from the ring main, turn off the lighting circuits and then very carefully un-wrap the big block and poke it with my multimeter.
I'm not going to re-wire the entire upstairs lighting circuit (I'd leave that to a professional) but I can at least make this not so dangerous and put it in a junction box screwed to a beam.

 

[cireland]

'Spidered lighting circuit'. Lovely.
Unfortunately, this scenario is way more common than any decent spark would like to see.
If done correctly it's actually perfectly acceptable. It maybe had a box originally that has been damaged beyond repair.
By your description you're handling it in the right way. You should probably take a few pics in case any of the conductors come loose or snap during the process. That way, you have something to refer to.

 

[davelittlewood]

'Spidered lighting circuit'. Lovely.
Unfortunately, this scenario is way more common than any decent spark would like to see.
If done correctly it's actually perfectly acceptable. It maybe had a box originally that has been damaged beyond repair.
By your description you're handling it in the right way. You should probably take a few pics in case any of the conductors come loose or snap during the process. That way, you have something to refer to.

Thanks cireland,
I've got load of photos of the wiring on my TVR.... If you think that domestic wiring can be a nightmare....

 

[cireland]

Think we could all tell stories of 'Huh...wtf' moments.

 

[DefyG]

It sounds like you are describing what I think was called a RB4 junction box which was an accepted method of wiring lighting circuits (1960's?? I think). Feed from consumer unit then cables to switches and lights all run individually from there.

 

[davelittlewood]

It sounds like you are describing what I think was called a RB4 junction box which was an accepted method of wiring lighting circuits (1960's?? I think). Feed from consumer unit then cables to switches and lights all run individually from there.

Maybe but the house was only built in the 80s! (1980s )

 

[cireland]

Pretty sure wago make one now.

 

[davelittlewood]

Pretty sure wago make one now.

Yep, already got a load of wago connectors, just nip off to screw fix to get a large junction box

 

[DefyG]

Pretty sure wago make one now.

The M3 box? is it MF?

 

[brianmoooore]

'Spidered lighting circuit'. Lovely.
Unfortunately, this scenario is way more common than any decent spark would like to see.

Since lighting circuits became 'complicated', with multiple lamps per room, and lamp fittings of dubious origin with no provision for loop in became the norm, this has been my preferred way of wiring lighting circuits, but always with the spider's centre in a readily accessible, labelled (including each individual cable), box, suitable for the purpose.

 

[davesparks]

It sounds like you are describing what I think was called a RB4 junction box which was an accepted method of wiring lighting circuits (1960's?? I think). Feed from consumer unit then cables to switches and lights all run individually from there.

Not just was, it is still a perfectly acceptable mothod of wiring a lighting circuit which, when installed correctly, is very easy to fault find and modify in the future.

 

[cireland]

I now do loop in at switches so there are neutrals present. I thought this was more or less standard now.

You're version is the proper way, that's not what the OP is dealing with though. I did mention done properly it's acceptable.

As for the wago box, I mistook the wiring centre for a lighting junction box. Think it's for heating now though.
As long as wagos are boxes designed for them with strain relief etc., i think it does count as MF.

 

[brianmoooore]

MF only required if the box is inaccessible. If the box is inaccessible, then many of the advantages of this circuit arrangement are lost.
You can still provide a neutral at every switch box with this method, but just the one in, instead of one in and several out, filling up the restricted space inside a box.

 

[DefyG]

Think it's for heating now though.

See them every where so thought it was a general purpose box, not specifically for heating, but wasn't sure if classified as MF?

 

[davelittlewood]

It sounds like you are describing what I think was called a RB4 junction box which was an accepted method of wiring lighting circuits (1960's?? I think). Feed from consumer unit then cables to switches and lights all run individually from there.

if it was actually in a box....
It's just a load of wires connected into a massive clump of choc connectors in a few yards of tape, no labels buried under 6 inches of rock wool.