Chris Green wrote:

Moving further on in my consumer unit replacement exercise I have just
been looking at my 18th Edition 'On-Site Guide' and it says in section
2.2.6:-

(c) The cable installation entry method shall, so far as
reasonably practical, maintain the fire containment of the
enclosure. It is essential that account be taken of the
manufacturer's instructions, if any.

This can generally be achieved by the installer ensuring that
cable access holes in the enclosure do not leave gaps greater than:-

* 1.0mm for the horizontal top surface and
* 2.5mm for all other surfaces of the enclosure that are
accessible after installation

.....


How can one possibly manage this with flat T&E cable? Do new CUs come
with oval cut-outs sized for T&E - it seems rather unlikely. Would
any trunking used to cover cables as they enter the CU also have to be
'non-combustible'?

I'm aiming to mount the CU fairly high up, about 75 to 100mm from the
ceiling. Nearly all the cables will be coming down from above,
through the plasterboard ceiling. Would it satisfy the regulations to
encase the whole space between the CU and the ceiling in metal?

I believe the answer is intumescent goo - fortunately I have no personal
experience.


--

Roger Hayter