Date : Fri, 11 Sep 2009 00:05:36 +0100
From : rs423@... (Mick Champion)
Subject: Leccy @ Acorn World '09
Phil Blundell wrote:
> On Thu, 2009-09-10 at 21:00 +0100, Mick Champion wrote:
>
>> Jonathan Graham Harston wrote:
>>
>>> [someone else wrote:]
>>>
>>>> kept, our 2 amp round pin and 5 amp round pin socket outlets (brown and
>>>>
>>>>
>>>
>>> Bad installation practice.
>>>
>>>
>> Not when it was first installed maybe? Do round plugs have grandfather
>> rights?
>>
>
> Round plugs (or, rather, the sockets for them) to BS546 are still
> explicitly permitted by the Regulations. There's no need for any
> grandfather rights in this situation.
>
That's good. So long as the circuit is correctly fused at the
distribution point and the circuit has modern cable, it is as safe. I
never understood why 13amp plugs were sold with 13 amp fuses as the
norm. It's a wrong side failure in my opinion. Educate the nation by
selling plugs with 3 amp fuses as you'd soon learn when your iron blows
the fuse you need a larger one.
> That said, with the exception of lighting circuits, I can't think of any
> particularly good reason why one would want to include BS546 sockets in
> a new installation. Using round pin plugs on regular appliances is
> perfectly legitimate but it would be a strange thing to want to do.
>
Square 13 amp fused plugs are what? 35 to 40 years old now??? Nowt has
come with a round plus in either size in all that time so I too fail to
see any good reason to install round sockets aside from novelty or
themed / historical reasons. Us Brits don't like letting go though, This
list is evidence of that. ;-) Why should we be forced to dump BBC's,
sockets, imperial or anything else we like so long as it's safe. Why
should anyone care! Are round pinned plugs still used in lighting? I
remember in my primary school the PA / speaker boxes in all the
classrooms used to plug in using the smaller of the round plugs. I
wonder what standard that adopted :-)
>
>> Regulations only apply to new installations, but what does a
>> safety certificate cover?
>>
>
> There isn't really any such thing as a single "safety certificate" for
> electrical installations in the same sense as there is for (say) gas
> appliances. If the installation is being tested, either following
> alterations or just as a periodic check, the resulting documentation
> will specify the exact scope of the tests that were carried out.
>
That's fair enough I suppose. So long as they don't exclude any dodgy
bits. Even with gas there are grandfather rights though. If you have a
small geezer without a flue over a kitchen wash basin (so carbon
monoxide pours into the room), it seems to be acceptable so song as a
warning sticker is placed on it saying not to run the thing for more
than 2 minutes. It would be illegal to install one now though. I'm sure
this must exclude bathrooms as many folk have snuffed it in the bath
filling the tub with that extra bit of hot.
>
>>>> By the way, I have never understood why we can't have socket outlets in
>>>> bathrooms, etc, yet France and Gernmany, for example, have no such qualms.
>>>>
>>>>
>>> As
>>>
>>> 'cos electricity and water don't mix!
>>>
>>>
>> Agreed 100%
>>
>
> Funnily enough, the current regulations do in fact permit socket outlets
> in bathrooms (though still subject to some constraints). The blanket
> prohibition on such outlets was abolished in the 17th edition.
>
Aside from a shaver socket, is their any real need for sockets in the
bathroom? I wonder why this has been accepted even with constraints.
Something to do with Europe perhaps???
>
>> Is a
>> round plug with no fuse but has a 5 amp fuse at the fuse box (6amp MCB
>> breaker at the distribution unit) any safer than the same piece of
>> equipment with a appliance cable rating of 3 amps with a 13 amp fuse and
>> 32 amp breaker? I don't think so. Would it pass a safety test..... Pass
>> (that is I've passed on the answer) ;-)
>>
>
> The former (round-plug) scenario probably is slightly safer in that
> situation, although in practice the risk of an appliance overloading its
> own flex is fairly low so even the latter scenario is not very likely to
> result in disaster; a 3A flex protected by a 13A fuse is, after all,
> about the same level of protection as most small appliances enjoy in the
> rest of Europe. But of course that doesn't make it good practice, and
> indeed the appliance would fail a PAT inspection if it was fitted with a
> 13A fuse on a 3A flex.
>
Sorry, that was a rather poor and unlikely scenario wasn't it <holds
head in shame>. It was always said always said that I "must try harder"
and NEVER "could do better" :'( Swi*es!!! I concede that if something
goes wrong, it's usually either an open circuit or dead short so
yes..... A dead short would blow a 30 amp fuse before the cable could do
any damage.
To JGH. I really enjoyed reading your piece on "Electrical supply to
multiple flats" plus the wiring diagram. It seemed like the supplier was
very good at telling you what you couldn't do, and not so forthcoming
about what you could. Glad it had a happy ending. Useful to know there's
a difference between an installation rating and a manufacturer ratings
of cable.
Mick