Ring final with 4mm legs

[Leesparkykent]

In a new build I struggle to see how you would get 4mm T&E to comply on a 32A circuit breaker unless its supplying a fixed load that pulls no where near 32A.

 

[EastAnglian]

In a new build I struggle to see how you would get 4mm T&E to comply on a 32A circuit breaker unless its supplying a fixed load that pulls no where near 32A.

Comply with which parameter specifically?

 

[Leesparkykent]

Comply with which parameter specifically?

current carrying capacity.

 

[EastAnglian]

Yes - fair point in a new build other than 'clipped direct' reference method ...... I must learn not to generalise when posting

 

[kingeri]

How about an unfused spur wired in 4mm but serving 2 double sockets, off a ring final wired in 4mm? Found this today. I don't think its actually dangerous, but does it comply? Ring final is about 20m total length and spur about 3m.

 

[EastAnglian]

It certainly doesn't comply with Figure 15B of the Informative Annex 15.

 

[kingeri]

True enough but could it be regarded as a 4mm radial, after all you could remove one leg from the DB and that's what it would be.

 

[HandySparks]

It certainly doesn't comply with Figure 15B of the Informative Annex 15.

Maybe not, but it's as safe as a radial wired in 4mm² in the same location.

 

[kingeri]

We must have been thinking along the same lines at the same time there!

 

[EastAnglian]

Ah yes, I just re-read the original and see its a 4mm RFC - doh! In which case I would agree with the above!