New House, Service Head

[EFLImpudence]

Also holiday homes in otherwise virtually uninhabited villages.

 

[ban-all-sheds]

And how would the insulating properties of the second layer be tested to prove this then?

By having both layers made from the same material?

 

[Risteard]

And how would the insulating properties of the second layer be tested to prove this then?

By having both layers made from the same material?

Just because they are both PVC does not mean that the composition is the same. Mechanical protection is the sole purpose of the sheath.

 

[JohnW2]

Mechanical protection is the sole purpose of the sheath.

So would you be happy if it were made out of an (unearthed) pretty conductive material?

Kind Regards, John

 

[Risteard]

Mechanical protection is the sole purpose of the sheath.

So would you be happy if it were made out of an (unearthed) pretty conductive material?

Kind Regards, John

No, because those cables are constructed with the intention of the sheath being earthed (and in fact used as the cpc).

They are always considered to be exposed conductive parts and therefore must be earthed.

But we are not talking about MIMS cables here so it's not actually relevant to this discussion.

 

[wcavanagh]

So the mystery is solved.

 

[wcavanagh]

I have found that the split concentric goes into the loft, and terminates in these Hendley Blocks that are on the floor of the loft just inside the hatch (nice place that) The twin & earth and the dodgy rubber cable feeding the two CU's are run from these.

What is the best solution to this?

Cheers,
Will

 

[flameport]

What is the best solution to this?

Disconnect supply at the meter (the outside one)
Rip the entire lot out and start again.

 

[Echo the husky]

Is that rubber twin going out? No fusing down either, and no cpc. Total rubbish!

 

[wcavanagh]

Yes the rubber cable is off the same blocks.

 

[securespark]

What is the best solution to this?

Disconnect supply at the meter (the outside one)
Rip the entire lot out and start again.

I would use SWA.

 

[JohnW2]

Mechanical protection is the sole purpose of the sheath.

So would you be happy if it were made out of an (unearthed) pretty conductive material?

No, because those cables are constructed with the intention of the sheath being earthed (and in fact used as the cpc). ... They are always considered to be exposed conductive parts and therefore must be earthed.

Those who had, at some point in history, wired parts of my house with lead-sheathed cables clearly had not heard about that 'always'

Kind Regards, John

 

[stillp]

There are a lot of DI cables in aerospace applications.

 

[ban-all-sheds]

No, because those cables are constructed with the intention of the sheath being earthed (and in fact used as the cpc).

What about cables with metallic mechanical protection which is not intended to be the cpc?

 

[JohnW2]

There are a lot of DI cables in aerospace applications.

That doesn't surprise me - only a few minutes ago I posted some comments about 'redundancy' in aeronautical engineering.

In terms of the standard domestic, commercial and industrial wiring cables, does the specification for the 'sheathing' include requirements in relation to its insulating properties?

Kind Regards, John