Wires inside a cable - questioning

[FrodoOne]

A bare Earth conductor does cater for damage to the insulation of the Live and / or Neutral conductors in the cable by providing a path to Earth without the need for any insulation on the Earth conductor to be damaged as well.

However, regulations in the EU since, 2004 (and in Australia/NZ, since 1966) require the use of insulated "Earth" conductor.

 

[Ragnar_AT]

EU countries can have national changes to the harmonisation documents and pretty much all do. Norway happily uses bare CPCs, although the same CSA as the other conductors. Most central European countries have exclusively user insulated CPCs since before WWII though.

 

[SUNRAY]

Would you consider installing "Solid" conductor 4 mm² (and larger) Twin and Earth Cable (if it were available - and slightly cheaper)
as opposed to installing "Stranded" conductor cable of the same CSA?

I didn't see mention of 4mm²

In addition, the use of "Solid" copper conductors (above 1.0 mm² [CSA]) up to 2.5 mm² (CSA)
instead of slightly dearer "stranded" conductors of the same size
makes installing such cables more difficult and time consuming.

WHAT?

However I certainly don't find installing solid 2.5mm² any more onerous than 7x 2.5mm² in singles, twin or T&E, however IMO solid T&E wins hands down for a neater finish when clipped direct.

 

[opps]

First thing, I have taken heavy painkillers, I am tired, and I am autistic, I may and often do blabber on. I will try hard not to.

Okay.

I have watched many YouTube videos about all aspects of the trades, I have even used, or seen people do in real life, but I have always wanted to know, when someone lays wire, first fixing? They often lay down a grey cable with 3 sets of copper wire, 2 are sleeved one brown and one blue, they then cut off sleeves for the bare copper wire and put the wire in the sleeve. I also know you can get the same cables but all are sleeved. I think they are called something like 2 core and earth and 3 core cables.

Questions being is this just a money saving thing, does it make it easier to install if the earth has no sleeves?

Why do we have these cables? What are the pro and cons?

thank you.

I haven't read the posts on the second page... my understanding is that in post war austerity Britain, we decided to reduce the requirement for copper and opted for the ring system rather than a radial system which would require thicker individual cables. I guess it is cheaper to specify an earth that is not sleeved. That said, sleeving the earth is pretty trivial.

 

[SUNRAY]

EU countries can have national changes to the harmonisation documents and pretty much all do. Norway happily uses bare CPCs, although the same CSA as the other conductors. Most central European countries have exclusively user insulated CPCs since before WWII though.

Like France in their round version of T&E with bare CPC.

 

[plugwash]

Would you consider installing "Solid" conductor 4 mm²

The german "NYY-J" cable type is solid up to quite large sizes and I've certainly heard of UK electrians using it.

 

[SUNRAY]

The german "NYY-J" cable type is solid up to quite large sizes and I've certainly heard of UK electrians using it.

Oh yes certainly do - and I have. IIRC 6mm² is also solid. I don't think I've dealt with anything bigger than that.

 

[JohnW2]

However, regulations in the EU since, 2004 (and in Australia/NZ, since 1966) require the use of insulated "Earth" conductor.

I wonder why, since I can see some definite 'safety advantages'of having a bare CPC in a multi-core cable?

 

[Ragnar_AT]

Oh yes certainly do - and I have. IIRC 6mm² is also solid. I don't think I've dealt with anything bigger than that.

The largest you can get is 16 mm2 solid, which must be a pig to work with.

 

[JohnW2]

The largest you can get is 16 mm2 solid, which must be a pig to work with.

sounds more like 'metalwork', or maybe even plumbing, than 'electrics' to me

 

[SUNRAY]

The largest you can get is 16 mm2 solid, which must be a pig to work with.

I've worked with 16mm² single pyro which was bad enough thank you.

 

[Adam_151]

The german "NYY-J" cable type is solid up to quite large sizes and I've certainly heard of UK electrians using it.

There are sizes where it is not always solid core though, for instance even though 3c 6mm is often solid core, its also available as stranded in that size.

Eland datasheet: https://www.elandcables.com/handler...media/38379/nyy-j-pvc-0-6-1kv-power-cable.pdf may be slight variations between manufacturers