Stranded T&E

[The Medway Handyman]

JOOI when did stranded 2.5mm T&E change to solid core & why?

[Dave Plowman (News)]

You can still get stranded 2.5mm in singles for conduit use.

You're probably thinking of 7/0.29 which was the predecessor of 2.5 TW&E. It changed with metrication of such things around 1970. Solid core is likely cheaper to make.

[Andrew Gabriel]

IIRC, with metrification, so 2.5mm T&E has always been solid core.

The stranded predecessor was 7/.029 (with 3 strands for the CPC), although it was actually larger capacity than 2.5mm (almost 3mm CSA).

Larger sizes of T&E are still stranded, or they would be too difficult to bend.

[Roger Mills]

I would guess late 60's or early 70's but don't know exactly - or why.

My house was built in 1967/8 and extended in the early 70's (before I bought it). The original part is wired with stranded and the extension with solid.

[Edgar]

Some early metric 2.5 T&E cables had a reduced size CPC - 1.0 instead of the newer 1.5 .

Edgar

[ARW]

The 4th edition gave the 7/0.029 a current rating of 25A when clipped direct.

The full answer is in this article-:).

[ARW]

And you can buy stranded 2.5 T&E

[The Medway Handyman]

Cheers, interesting that.

[SteveW]

I've got the opposite. My cooker point is wired with 16mm2 T&E and has an oversized CPC - I got it free, 'cos the manufacturer made about a mile of the stuff before realising they had the wrong sized CPC and then decided they couldn't sell it 'cos it was not to the standards :)

SteveW

[Andrew Gabriel]

I used 16mm T&E to supply a computer room dist board. A right bugger to bend, even though it's stranded.

25mm is the largest T&E size.