Type of wire.

[uncletone]

Hi,
I've been swapping some light switches and light fittings recently and being an older house, late 70's I think.
I found the lighting circuit runs off this wire, this being the live to all the switches, with an accompanying sheathed (red or black depending if its from the switch to light or the light to another light) and earth running along inside it.
The sockets run off twin and earth. So i'm wondering if this was the normal setup back in the day and what would you call this type of wiring with the live being separate.
Seems weird to me not to just use twin and earth for the lot unless 1.5mm didn't exist.
Thanks

 

[EFLImpudence]

It's just single insulated and sheathed (plus earth) for when only one wire is required from point to point - switch to switch and/or switch to light as you have realised.

Nothing normal nor odd.

 

[winston1]

Seems weird to me not to just use twin and earth for the lot unless 1.5mm didn't exist.
Thanks

1.5mm would be oversized if it did exist. 1.0mm is the size for lighting. What you have is probably 3/029 imperial cable.

 

[JohnW2]

What you have is probably 3/029 imperial cable.

In "late 70s" ?

 

[winston1]

In "late 70s" ?

I did think about that and decided that “he thinks” late 70’s was mistaken. The cable certainly looks like imperial to me.

 

[JohnW2]

I did think about that and decided that “he thinks” late 70’s was mistaken. The cable certainly looks like imperial to me.

It does, not the least because it is certainly stranded. However, I may be wrong but IU had a feeling that there was a brief period during which stranded metric T+E was available?

... and I suppose I should have added that 3/029" was closer to 1.5mm² than to 1.0mm² - so I wonder what you thought about the use of that for lighting circuits?

 

[AndyPRK]

It's confusing.

The cable certainly looks like imperial to me. (stranded)
But the green earth sleeve is more 70's

Old cable stock installed in early half of 70's I guess

 

[bernardgreen]

I did think about that and decided that “he thinks” late 70’s was mistaken. The cable certainly looks like imperial to me.

The type of wire / cable used in a house re-wiring project may not be the correct / latest / modern type of cable.

A house built in the 1990's or later could have been wired or re-wired using old stock cables from the 1960's.

1.5mm would be oversized if it did exist. 1.0mm is the size for lighting.

1.0 mm² is adequate for lighting supplied by a 6 Amp MCB. 1.5 mm² is also acceptable for lighting

 

[AndyPRK]

1.5mm would be oversized if it did exist.

Not really oversized. The Irish seam to insist upon it.

 

[winston1]

Not really oversized. The Irish seam to insist upon it.

Well that says it all

 

[winston1]

It does, not the least because it is certainly stranded. However, I may be wrong but IU had a feeling that there was a brief period during which stranded metric T+E was available?

... and I suppose I should have added that 3/029" was closer to 1.5mm² than to 1.0mm² - so I wonder what you thought about the use of that for lighting circuits?

Never come across stranded metric cable in those sizes.

3/029 works out at 1.28mm2 so midway between the two sizes. 1/044 [=0.98mm2] was also used for lighting but as far as I know singles not T&E.

 

[Astra99]

1/.044 was definitely available in twin rubber sheathed (no earth!!!!!). My parents 1938-built house had it on the lighting circuit, but the 2-pin sockets (also on the lighting circuit) were wired in 3/.029

 

[john4703]

Old cable stock installed in early half of 70's I guess

Using old cable can be confusing. A couple of months ago I rewired the lighting circuits in a boiler room, a simple job, one switch, four light fittings. Nothing seemed strange until I realised the cable was red and black 1.0mm T&E. There is a nice sign on the consumer unit warning people that there is a mix of colours of cable so I left my work as it was. I just wonder how long that drum of cable had been lurking at the back of my workshop. Will someone be confused to find red and black cable with yellow/green earth sheathing?

 

[securespark]

But the green earth sleeve is more 70's

Green was prohibited from 1978, when it was superseded by green/ yellow.

 

[Harry Bloomfield]

I've been swapping some light switches and light fittings recently and being an older house, late 70's I think.
I found the lighting circuit runs off this wire, this being the live to all the switches, with an accompanying sheathed (red or black depending if its from the switch to light or the light to another light) and earth running along inside it.

3.029 singles, plus 3.029 single with earth. 1970's -ish. The Appleby back box is a type intended to be a sunk in the wall type, not intenged for a surface mounting.