In article ,
wrote:
On Monday, 22 June 2015 11:05:10 UTC+1, John Rumm wrote:
On 22/06/2015 09:56, Jim x321x wrote:
John Rumm wrote in
:

with the existing setup, and I rarely get any inexplicable tripping
of the circuit breakers. As far as I am aware, the old fuse boxes
(even when fuses contained fuse wire) did what they were designed
to do, with no problems.

They did what they were supposed to - and will still do so. The main
thing your current setup lacks is RCD protection.


Thanks to all for the excellently helpful advice.

If I added an RCD covering the entire house (without replacing the
existing fuse box which is already fitted with MCBs, would that
constitute a change to the wiring and thus require building control
notification?

Firstly you don't want a single RCD covering the whole house - that is
a practice that was common during the 15th edition, but is deprecated
now since it offers no "discrimination" in the event of a fault (i.e.
the fault will take out the supply to the whole house, not just the
circuit causing the problem). So many circuits on one RCD are also
more prone to nuisance tripping in the first place.

A single RCD is moderately likely to not even work.

mine has - more than once. But if a single one doesn't work, why should
more than one?