Why no Sheath on Earth conductor ?

[Dazza1976]

Hi all,

Why is it that the earth conductor on twin and earth cable is not made with sheathing already on it ??
I seem to recall back in my college days, my tutor saying it was to reduce manufacturing costs, but surely it costs very little to do this.
With flex its made with a sheath already on the earth, so why not on standard twin and earth cable ??

I know it doesnt take much to put a bit of earth sleeving on there yourself, but it would make life easier if it was there in the first place.

 

[malcolmsanford]

I always assumed that it was the cost implication, also when T + E first came in, very few lighting installations were thought to require it, it was often cut off at the point of connection, so I would say it is an old school thought of a waste of money to sleeve it through out when often as not you cut it back, and it as never been thought cost effective to change.

 

[Paul.M]

I was told that its not sheathed to save money, size of the cable but the main thing is for safety. Better not to have sheath on the cpc incase someone cuts the t+e and makes it easier to short circuit live to earth and trip the mcb.

 

[nickblake]

you were right with your first comment its not done to reduce the cost , i must admit i always thought it was due to safety to go to earth quicker if there was a fault

 

[1shortcircuit]

Who would want to see T&E sheathed? After all, the CPC makes separating the cables so easy

 

[Paul.M]

Everything boils down to costs, that's why some manufactures are no longer putting earth terms in plastic wall mounted boxes any more.

 

[Dazza1976]

Who would want to see T&E sheathed? After all, the CPC makes separating the cables so easy

Very good point 1Short, that didnt occur to me when i wrote this post, probably best they keep it that way then !

 

[Deleted member 26818]

They use T&E with a sheathed earth on the continent. The earth conductor is the same size as the line and neutral.

 

[jay sean]

Im sure about 10 years ago I saw some twin and earth, and the cpc had the sleaving allready on it.
Ive never seen any since

 

[DurhamSparky]

cheese wire...???