Date   : Thu, 17 Sep 2009 12:57:29 +0100
From   : philb@... (Phil Blundell)
Subject: Leccy @ Acorn World '09

On Thu, 2009-09-17 at 11:24 +0100, Mick Champion wrote:
> I suspect the characteristics of each class of breaker is set down in the 
> regs?

Not explicitly.  The characteristics of MCBs are specified by IEC 60898,
and I think the regs defer to that standard (in much the same way as
they refer to BS1362 or BS3036 for the detailed specification of fuses).

> > Modern BS546 sockets are indeed equipped with shutters, and in fact the
> > Regulations require all socket outlets (irrespective of pin shape) in a
> > domestic installation to be shuttered.
>    
> So would all previously installed round sockets fail to pass a safety 
> inspection should they be of the "shutter free" variety?

They'd certainly be noted as "not conformant with current regulations",
but this doesn't necessarily mean that you would be obliged to
immediately rip them out.  Whether they would be labelled as actually
unsafe and requiring immediate replacement would be a somewhat
subjective decision by the inspector.

> 0,6 Mtrs is very close and could be easily reached from a bath. I'm 
> surprised at this.

I think the 0.6m spacing is intended more to prevent the accessory
itself from getting wet than for preventing simultaneous contact.  There
is no minimum spacing from a sink or basin, so it has always been
possible to place accessories where they could be touched with wet
hands.  Plus, the fact that there is no blanket prohibition on
accessories in this area doesn't mean that it is always a good idea to
put them there: you still need to apply common sense and comply with the
other requirements laid down in the regs.

As far as the shock risk goes, it's probably mitigated to some extent by
RCD protection, which is now mandatory for all bathroom circuits
including lighting.

p.