Digital switchover causes TV problems in Oxfordshire

Terry Casey wrote:
dswan wrote:

wrote:
On Feb 22, 10:55 pm, charles wrote:
In article ,
Martin wrote:

We have three phases. Dutch wiring is peculiar. No ring mains and the bog
standard set up limits you to a total of 16 amps. To use any sort of
electric oven you have to convert to three phase.
Ring main is a peculiarly UK system. It was invented to save on copper for
the post-war housebulding boom. Its major disadvantage is that plugs need
to be large enough to incoporate a fuse.

--
From KT24

Using a RISC OS computer running v5.16
But those postwar houses often had 15A sockets, and 15A plugs don't
have fuses.

Bill

Ah but they were always available, and still are (cost a bomb though):

http://www.neweysonline.co.uk/mk-ele...mation.raction

I always wondered why they didn't make much more extensive use of
those.

They're still available because BS standard 5A and 15A connectors are
still in use in some countries - particularly India and South Africa -
see types D & M in

http://users.telenet.be/worldstandar...city.htm#plugs

--

Terry

Yes, but do they use the fused versions of BS 546, like the one in my
link above?

"Terry Casey" wrote in message
...
dswan wrote:

wrote:
On Feb 22, 10:55 pm, charles wrote:
In article ,
Martin wrote:

We have three phases. Dutch wiring is peculiar. No ring mains and the
bog
standard set up limits you to a total of 16 amps. To use any sort of
electric oven you have to convert to three phase.
Ring main is a peculiarly UK system. It was invented to save on copper
for
the post-war housebulding boom. Its major disadvantage is that plugs
need
to be large enough to incoporate a fuse.

--
From KT24

Using a RISC OS computer running v5.16
But those postwar houses often had 15A sockets, and 15A plugs don't
have fuses.

Bill

Ah but they were always available, and still are (cost a bomb though):

http://www.neweysonline.co.uk/mk-ele...mation.raction

I always wondered why they didn't make much more extensive use of
those.

They're still available because BS standard 5A and 15A connectors are
still in use in some countries - particularly India and South Africa - see
types D & M in

http://users.telenet.be/worldstandar...city.htm#plugs



I like the bit which opines..
"The reason why we are now stuck with no less than 13 different styles of
plugs and wall outlets, is because many countries preferred to develop a
plug of their own, instead of adopting the US standard"..

The message
from Mark Carver contains these words:

Richard Tobin wrote:
In article ,
charles wrote:
Ring main is a peculiarly UK system. It was invented to save on
copper for
the post-war housebulding boom. Its major disadvantage is that
plugs need
to be large enough to incoporate a fuse.

They could have put fuses in the sockets.

No, because the fuse is there to protect the appliance's cable, (and not as
many believe the appliance itself). So for an appliance with a thinner
cable
you'd obviously need to change the fuse in the socket.

Exactly! The problem is that most folk don't realise this and will
often fit a 13A fuse in place of the 3A used to protect the 6 or 10 amp
rated flex on things like table lamps or those figure of 8 cords used on
mains/battery powered radios and the like.

If the appliance is anything more complex than a table lamp, it may
have its own half amp (or whatever) safety fuse built in to guard
against the fire hazard that can exist at much lower fault currents than
even a 1A plugtop fuse can provide[1].

The plugtop fuse's primary function is to prevent fault currents that
exceed the cord's maximum safe carrying capacity. If a suitably low
enough rating of plugtop fuse can also protect against equipment faults
(the table lamp is a classic example of this) then all the better.

[1] Small, low powered, devices complex enough to pose a fire hazard
under certain fault conditions will incorporate suitably rated safety
fuses which closely match the normal operating current of the equipment
which may be as little as 100mA or lower. These fuses can't protect
against cordage faults, that's the job of the plugtop fuse which still
needs to match the rating of the cordage being used.

--
Regards, John.

Please remove the "ohggcyht" before replying.
The address has been munged to reject Spam-bots.

On Feb 23, 3:30*pm, Peter Duncanson wrote:
On Tue, 23 Feb 2010 13:20:36 +0000, Terry Casey
wrote:
My memories might have been contaminated by a recent experience. I
bought a surface mounting box for a light switch. I attempted to remove
one of the knock-out sections to make a cable entry point. There was a
sharp breaking sound and I was the proud owner of a box in two pieces.
The whole of a corner had broken off. The knock-out section was still in
place.

--
Peter Duncanson

We often mount TV/SAT plates on patresses, and breakages are common,
even when you're used to doing it. I've found that Contactum ones are
as good as any.

Bill

On Tue, 23 Feb 2010 14:06:03 +0000, Adrian wrote:

charles wrote:
In article , Terry Casey
wrote:

The device to which you refer was a THIRTEEN amp RING MAIN connector
manufactured by Dorman & Smith. (I'm sure it's been discussed on here in
the past year.)

They were widely used on post-war council housing estates and the
suspicion is that D&S offered the sockets to local authorities at a much
lower price than the convention MK, Crabtree, etc., 13A type, knowing
that they'd recoup any loss from the ridiculously over priced (patented)
plugs and fuses that the householders would be forced to buy afterwards.


There were at least 3 contenders for the "ring main plug". NSHEB used yet
another one. In the end the MK version won, but I suspect the bulk of the
D&S installations happened before the current standard was agreed on

Do you remember the Wylex contender? They hung on for quite some time in
places.


Yes, I think I remember them - my gran's flat was supplied witht them
- ISTR that the 13A (?) plug could piggyback a 5A(?) plug
--
Cheers

Peter

On Feb 23, 2:05*pm, dswan wrote:
wrote:
On Feb 22, 10:55*pm, charles wrote:
In article ,
* *Martin wrote:

We have three phases. Dutch wiring is peculiar. No ring mains and the bog
standard set up limits you to a total of 16 amps. To use any sort of
electric oven you have to convert to three phase.

Ring main is a peculiarly UK system. *It was invented to save on copper for
the post-war housebulding boom. *Its major disadvantage is that plugs need
to be large enough to incoporate a fuse.

--
From KT24

Using a RISC OS computer running v5.16

But those postwar houses often had 15A sockets, and 15A plugs don't
have fuses.

Bill

Ah but they were always available, and still are (cost a bomb though):

http://www.neweysonline.co.uk/mk-ele...g-three-pin-fu...

I always wondered why they didn't make much more extensive use of
those.- Hide quoted text -

- Show quoted text -

Ten quid?

Bill

On Tue, 23 Feb 2010 06:05:28 -0800 (PST), dswan
wrote:



wrote:
On Feb 22, 10:55*pm, charles wrote:
In article ,
* *Martin wrote:

We have three phases. Dutch wiring is peculiar. No ring mains and the bog
standard set up limits you to a total of 16 amps. To use any sort of
electric oven you have to convert to three phase.

Ring main is a peculiarly UK system. *It was invented to save on copper for
the post-war housebulding boom. *Its major disadvantage is that plugs need
to be large enough to incoporate a fuse.

--
From KT24

Using a RISC OS computer running v5.16

But those postwar houses often had 15A sockets, and 15A plugs don't
have fuses.

Bill

Ah but they were always available, and still are (cost a bomb though):

http://www.neweysonline.co.uk/mk-ele...mation.raction

I always wondered why they didn't make much more extensive use of
those.

This one appears to be fitted with a 5A fuse - I remember my father
installing one for our washing machine - that didn't have a fuse
fitted
--
Cheers

Peter

In article
,
wrote:
On Feb 23, 2:05 pm, dswan wrote:


Ah but they were always available, and still are (cost a bomb though):

http://www.neweysonline.co.uk/mk-ele...g-three-pin-fu...

I always wondered why they didn't make much more extensive use of
those.- Hide quoted text -

- Show quoted text -

Ten quid?

If you must have a real MK it will cost that - I can get unbranded ones at
TLC for about £1; Duraplug "rubber" ones cost about £4.30 - Permaplug ones
about £2 less

--
From KT24

Using a RISC OS computer running v5.16

charles wrote:
In article , Richard Tobin
wrote:
They could have put fuses in the sockets.

but they didn't

Actually fused sockets were used for a while, until banned by the 7th
edition of the IEE wiring rules (1916). The concept of the fused plug
was patented in 1896 but early open wire implementations were so
dangerous that they too had to be banned (6th ed., 1911). Fused sockets
were discussed again in the 1940s, while the details for the new
universal plug and ring circuit system were being hotly debated.

For chapter, verse and a fascinating read go to the link below, download
the zip file offered and see the file ring_circuits_-_history.pdf

http://www.theiet.org/publishing/wir...ns/ringcir.cfm

--
Andy

On 23 Feb, 18:26, charles wrote:
In article
,
* wrote:

On Feb 23, 2:05 pm, dswan wrote:

Ah but they were always available, and still are (cost a bomb though):

http://www.neweysonline.co.uk/mk-ele...g-three-pin-fu....

I always wondered why they didn't make much more extensive use of
those.- Hide quoted text -

- Show quoted text -
Ten quid?

If you must have a real MK it will cost that - I can get unbranded ones at
TLC for about £1; Duraplug "rubber" ones cost about £4.30 - Permaplug ones
about £2 less

--
From KT24

Using a RISC OS computer running v5.16

Yes, but are those the fused ones you're talking about? Thats the
point I was making - that, contrary to what most think, it was always
possible to get fused BS546 plugs. The one in the picture is over £10
as its a fused one - I assume the reason it costs so much is that
there's practically no demand for them and therefore economies of
scale don't apply.

However, thats what I was trying to say (not very clearly) - rather
thandevelop a completely new system, I'm surprised BS 546 as an extant
system didn't simply get modified to use fused plugs such as the one
shown.