On Mon, 29 Jan 2018 18:52:49 +0000, Graham. wrote:

====snip unattributed quote===


You make an interesting point about making a recurring fault more likely
to be referred to a qualified person, but on balance I have to disagree
with you.

Rewirable fuses should be regarded as a legacy item in domestic CUs (as
indeed they are).

No argument there. However, "Legacy" doesn't always equate to 'unfit for
purpose'. :-)


The general public-at-large just does not have the skill to wire a fuse
correctly, they will route the wire incorrectly, use the wrong gauge of
wire, use any old piece of wire.

Yes, sadly (but no longer surprising in my rather long experience of
others' ignorance of basic physics), that's all too often the truth of
the matter. Fortunately, those who lack such fundamental knowledge will
employ those who have been trained[1] to install a modern electrical
wiring system complete with a nice shiny new CU blessed with ELCBs[2]
when moving into an older property that's been blessed by such legacy
fixtures and fittings.


With today's culture of moulded-on plugs and "No user serviceable parts
inside", I sometimes think electricity is more of a mystery to the
layman than his Edwardian forebears.

[1] I'm not surprised that you should think so. Even those 'trained' in
the 'modern' art of 'electrics', installing domestic electrical systems,
are often little more knowledgeable about the fundamentals of electricity
than their Edwardian forebears, relying almost entirely on a set of
regulatory requirements learnt by rote.

[2] Such modern replacements for the 'legacy' Wylex CU fusebox rather
neatly solves the one major weakness of such legacy kit by eliminating
the opportunity for end user sabotage whether due to ignorance or just
plain wilfulness which far outweighs the risk of fatal failure of a
circuit breaker thus making such rare failures a real but more acceptable
risk.

If we could discount end user sabotage, then a fuse would offer an
almost zero risk of 'failure to protect' compared to that of a circuit
breaker. Since we can't discount end user sabotage, the circuit breaker
wins out in terms of its overall safety risk. Furthermore, since modern
CUs are equipped with ELCBs rather than basic circuit breakers, the
overall risk of loss of life is even lower than what a correctly rated
fuse can provide, even after allowing for the minuscule risk of fatal
failure of said ELCBs.

--
Johnny B Good