Terry Fields wrote:
John Rumm wrote:

Terry Fields wrote:

Are any figures available that show injury and/or deaths rates are
less under the new regime (in this case an RCD CU) than the old (a
fused CU)?
Its a good question, and I don't know how easy it would be to get
figures in the exact form required... Until recently[1] deaths from
electrocution have fallen year on year in absolute terms for quite a
number of years, even though usage of appliances has risen. This won't
be attributable to just one improvement in safety, but a collective
effect of which RCDs have been a part quite a number of years now.

[1] In the last couple of years this trend seems to be showing signs of
reversing - strangely coincident with the introduction of Part P

That was my impression too, based on comments on the ng; but I was
wondering if any officcial figures were available.

It seems to be common for 'the authorities' to set a policy (i.e Part
P) but to fail to put in to place any monitoring of the effects of
that policy. Perhaps it's a question of 'if you don't want to know the
answer, then don't ask the question'.

IIRC there was a question asked in the house recently on the apparent
rise coincident with part P. A search of Hansard will probably turn up
something.

A casual reading of the group suggests that there are a number
potential benefits from the technical advances in going from the
former to the other latter - but how does it work out in practice?
Not sure I follow the question - do you mean what will be the change in
user experience? or the actual process of making the change?

It was just a convoluted way of trying to link the technicalities such
as the release time for an RCD, or better earthing arrangements, with
reduction or otherwise in casualties, but if there's no figures
collected, then there's no way to link the cause with the effect. It
all seems to run on a 'feel-good' factor.

There are figures available and well documented for the effects of shock
and the implications of shock current and duration of exposu

http://www.memonline.com/rcd3.html

So RCD protection offers very much more than a "feel good factor" -
unless you include the ability to breathe and absence of ventricular
fibrillation as "feel good" ;-)

Note also RCDs are used not only to lessen shock risks, but also as a
earth fault protection mechanism. A TT install with a 6 ohms fault loop
impedance could end up sinking 40A for an extended period of time into a
protective conductor without tripping a typical 32A MCB on a power
circuit. This would (in the absence of the RCD) result in at best cable
damage, and possibly fire.



--
Cheers,

John.

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