Octopus wiring lights

[Bobby34]

So I was doing some work at my sisters house and one of the jobs she wanted was her lights looking at, i looked at them and quite honestly thought if I start touching these i'm going to end up rewiring the lighting circuit. I'm newly qualified and happy to put my hands up if something is looking like I may be out of my depth but basically, you had light switches in the kitchen turning the living room lights on, when you turn a different light on in the kitchen then one of the two kitchen light fittings would dim and a separate light would turn off it was just all over the place.

Long story short I said to get a more experienced sparks round to have a look but if she could let me know what the issue was I'd be interested in knowing, she came back to me today and said that he said it was what is known as Octupus wiring and is his pet hate and was a common way of doing things back around the 60's.

Could someone just explain a bit more what octopus wiring actually is and any pro's con's?

Many thanks

 

[Nebu1a]

Never heard this phrase before. Sounds like its wired from central junction box and some of the switch lives are incorrectly connected.

 

[Strima]

Nothing wrong with an octopus wiring method just not seen often as we tend to loop in and out using a three plate.

Needs some fault finding doing on it, would be good practice for you.

 

[Nebu1a]

Pros are usually a single cable at the switch or light fitting so easy to terminate fittings. Cons are a junction box hidden somewhere under the floor making future maintenance a pain in the proverbial.

 

[Nebu1a]

So is octopus wiring 3plate?

 

[Nebu1a]

Sorry misread. Junction box method is ok in a loft space or if the Jbs have been put in say the airing cupboard or similar

 

[Strima]

JB should ideally be placed in an accessible area but they often get boarded over in lofts. Very easy to add smokes etc.

 

[7029 dave]

It is a junction box wiring system.

 

[A032701]

each jb has four terminals.
terminal 1 - permanent live, this runs out to the next jb for the next room. another cable also runs to the switch
terminal 2 - switch live. this comes from the switch and goes to the lights.
termonal 3- this is neutral.
terminal 4 this is cpc

 

[DPG]

Alban, that's not octopus wiring.

 

[A032701]

sorry that is a junction box system as per 7029 dave said it would have been.
an octopus system consists of a large terminal box where all the cables run into from the switches and lights

 

[telectrix]

this is octopus.1 central JB for all lights on the floor.the green is lights.

 

[Bobby34]

Yea that seems like the sort of thing, ok glad it's an actual thing and glad I didn't jump straight in after looking at that pic haha, I will speak to the sparks when I get a bit more time and gain some experience points , thanks guys

 

[SparkyChick]

And in reality it could look something like this (although this particular box contains power and lights).

 

[Bobby34]

Oh wow great picture, many thanks sparkychick

 

[Lucien Nunes]

Yes, that's genuine 'Octopus', the trade marked wiring system, although the term is also used generically to mean one big junction box with a lot of cables. The idea came into its own with the advent of prefabricated housing where all dimensions were exactly identical. The octopus box was factory-made and tested with tails of the right lengths to reach the lighting points and switches. On site, the sparks would place the octopus in position, unroll the cables and pull them in.

Cost a bit more in cable but saved time on site, plus one end of every cable run was terminated under ideal conditions at the factory so potentially more reliable.

 

[SparkyChick]

Oh wow great picture, many thanks sparkychick

As best as I can tell, that was installed in 1957 and was in service until the cabling failed completely in 2018.

For lighting, the modern equivalent I guess is these:-

Surewire - Pre-wired Maintenance Free Lighting Junction Boxes - https://www.surewire.co.uk/

 

[Lucien Nunes]

You kept it, I hope?

 

[SparkyChick]

You kept it, I hope?

Hell yes... I forgot I don't have a full waste carriers licence and it fell into one of my toolbags

 

[Starjack]

Stupid thread title, please tell me someone else was looking forward to a video of an octopus wiring lights up.

 

[KEV 1 N]

Stupid thread title, please tell me someone else was looking forward to a video of an octopus wiring lights up.

You mean like this?......

 

[happysteve]

Modern equivalent:
Products and Benefits - Surewire - https://www.surewire.co.uk/products/light-and-switch-junction-boxes/products-and-benefits/

 

[freddo]

There is some lighting in a local club wired in a similar way, 32 cables, many 3core and earth, wired into a central heating wiring centre.

 

[littlespark]

That’s a picture of a neat joint box... most look like a square plate of pasta.

We did used to call them spaghetti joints.

It sounds like the house in the OP needs a little time spent testing out each cable. There may be nothing else wrong than a couple of mixed up cables.
Access to the box will be the problem if it’s under carpet or flooring. The floorboards themselves will have a hatch above the box

 

[GBDamo]

Have used variations of this principle when converting switched modular lighting to PIR LED panels, can be a lot quicker that sorting the original fixed wiring, not always but a handy thing to use occasionally.

 

[telectrix]