'Perfection' my arse

Johny B Good wrote:

I understand that, in Holland at least, they use a bi-phase
distribution in domestic wiring. Two "live" wires of 110v rms in
antiphase with a neutral/earth which supplies the nominal 220v (now
called "230 volt" to harmonise with the UK and other countries using
the 240v standard (likewise labelled as 230v).

Having two live phase wires requires a 2 pole switch, it's not a
'luxury item' designed to save the need to worry about polarity
between a live and neutral connection to an appliance. There is no
neutral for a 220v appliance.

Many years ago I built some equipment for use in Moscow. I was told that
all mains connections had to have double pole switches and fuses on both
conductors, because both conductors were 'live'.

Bill

Bill Wright wrote:

Many years ago I built some equipment for use in Moscow. I was told
that all mains connections had to have double pole switches and fuses
on both conductors, because both conductors were 'live'.

Yes, that's right - I've had to do the same thing.

In one sense it's a great idea: each live is only 120V wrt earth, so
electrocution is much more rare. Double-pole switches are no problem.
It seems a far better idea than ours, where we have two conductors at
essentially the same potential, which is, frankly, a wasteful design
and the higher voltage results in higher electrocution risk.

To me it seems like it cleverly combines the best of the American and
European systems: 120V to earth for increased safety, 240V between the
conductors for high power and low current.

My concern is that when one fuse has blown the equipment is still
'live'. I wonder if anyone's been caught out like that.


--
SteveT

"Bill Wright" wrote in message
...
Johny B Good wrote:

I understand that, in Holland at least, they use a bi-phase
distribution in domestic wiring. Two "live" wires of 110v rms in
antiphase with a neutral/earth which supplies the nominal 220v (now
called "230 volt" to harmonise with the UK and other countries using
the 240v standard (likewise labelled as 230v).

Having two live phase wires requires a 2 pole switch, it's not a
'luxury item' designed to save the need to worry about polarity
between a live and neutral connection to an appliance. There is no
neutral for a 220v appliance.

Many years ago I built some equipment for use in Moscow. I was told that
all mains connections had to have double pole switches and fuses on both
conductors, because both conductors were 'live'.

A double pole switch is still a luxury unless you want to put your fingers
inside the appliance - and in that case it's better to unplug it.

--
Max Demian

Martin wrote:

There are no gates on the sockets small children can and do push bits
of wire into them.

Bloody hell! I'm amazed.

--
SteveT

"Bill Wright" wrote in message
...
Quiz show on BBC 1. The contestant, a teacher, didn't know what colour the
live wire is in a 13A plug, yet remarked that he had taught kids how to
wire plugs. Then the rest of them were far from sure. Where do they get
these people?

Bill

They are red in your wiring aren't they Bill?

On 22/01/2014 11:47, Steve Thackery wrote:
Martin wrote:

There are no gates on the sockets small children can and do push bits
of wire into them.

Bloody hell! I'm amazed.

It's quite usual. In Switzerland you can even find similar three phase
domestic style sockets in light industrial/public buildings, as some
UK wiremen I was working with found to their cost. They turned up with
their ghetto blaster, took the UK plug off and stuffed the L and N wires
into two holes at random. The ghetto blaster worked perfectly for about
three seconds, before it stopped, and filled the room with the smell of
burnt components :-(




--
Mark
Please replace invalid and invalid with gmx and net to reply.

On Wed, 22 Jan 2014 03:40:37 +0000, Bill Wright
wrote:

Johny B Good wrote:

I understand that, in Holland at least, they use a bi-phase
distribution in domestic wiring. Two "live" wires of 110v rms in
antiphase with a neutral/earth which supplies the nominal 220v (now
called "230 volt" to harmonise with the UK and other countries using
the 240v standard (likewise labelled as 230v).

Having two live phase wires requires a 2 pole switch, it's not a
'luxury item' designed to save the need to worry about polarity
between a live and neutral connection to an appliance. There is no
neutral for a 220v appliance.

Many years ago I built some equipment for use in Moscow. I was told that
all mains connections had to have double pole switches and fuses on both
conductors, because both conductors were 'live'.


Quite obviously a Bi-phase distribution system. It adds a bit of
extra cost (more copper and 2 pole switches) but this is simply the
cost of a 'safer' system (only having 110v wrt earthed metalwork
compared to 220v for example, significantly reducing the electrocution
risk).

That does rather lend some credence to my description of the dutch
wiring practice (but I'd still appreciate having this confirmed by
someone who actually knows).
--
Regards, J B Good

On Wed, 22 Jan 2014 03:21:21 -0600, "Steve Thackery"
wrote:

Bill Wright wrote:

Many years ago I built some equipment for use in Moscow. I was told
that all mains connections had to have double pole switches and fuses
on both conductors, because both conductors were 'live'.

Yes, that's right - I've had to do the same thing.

In one sense it's a great idea: each live is only 120V wrt earth, so
electrocution is much more rare. Double-pole switches are no problem.
It seems a far better idea than ours, where we have two conductors at
essentially the same potential, which is, frankly, a wasteful design
and the higher voltage results in higher electrocution risk.

To me it seems like it cleverly combines the best of the American and
European systems: 120V to earth for increased safety, 240V between the
conductors for high power and low current.

My concern is that when one fuse has blown the equipment is still
'live'. I wonder if anyone's been caught out like that.

I'm not sure how that issue would be addressed in a fused system.
However,with circuit breakers, it's possible to use 2 pole breakers
which can isolate both lives regardless of whether it's a live to live
short or a single live to earth or neutral short.

I suspect this is another reason to use a live and neutral feed for
the lighting circuits (and, in the states, low power devices, hair
driers, radios, TV sets and so on fed off a live and neutral).

You still have the benefit of reduced elecrocution hazard. It's
normally only heavier electrical loads (washing machines, electric
ovens and so on) in the states that employ 234v bi-phase (still with
reduced risk of electrocution).

In most of europe, the wall outlet voltage is usually the full '230'
volts (whether bi-phase or not).

I'm sure I've seen a list of worldwide voltage standards somewhere on
the internet which might also mention the use of simple live/neutral
or Bi-phase distribution standards. It's been a long time since I last
looked so I only have a vague notion that this sort of info wasn't
particularly evident.
--
Regards, J B Good

On Wed, 22 Jan 2014 12:34:28 +0100, Martin wrote:

On Tue, 21 Jan 2014 17:06:28 -0000, "Woody" wrote:

"Brian Gaff" wrote in message
...
Probably colour blind.
Whatever next. I used to joke that they made it brown as
it matched the colour of what came out when you ****
yourself after surviving the shock of getting it wrong.

I'd personally like the outside to be rough so I could
still wire a plug.

Of course I predicted this would happen when they started
requiring manufacturers to fit plugs. I notice a lot of
the fitted plugs are just adaptors with a europlug
clamped inside it, meaning presumably that it does not
matter any more.
Brian


Well it doesn't as, if it has a Euro adapter and thus
presumably a Schuko plug inside it, the power switch will be
double pole and the appliance will likely be double
insulated. It is only we Brits (and the Irish who use the
same) who bother about polarity so that we can do it cheap
and only switch the live wire.

You never saw a Dutchman get a shock because the polarity was the wrong way
round on a light bulb fitting. UK electrical fittings and house wiring are
vastly superior to the Dutch equivalent. A standard Dutch house could only use a
maximum of 16 Amps. Most of the sockets in my house have no earth. I lived at
one time in a then new Dutch block of flats, where none of the sockets were
earthed. I know of a case in Italy where a neighbour's dog ****ed on a socket
and died. There are no gates on the sockets small children can and do push bits
of wire into them.

That's all rather fascinating. I presume the first sentence is a
reference to the use of edison screw light fittlings (which reinforces
the idea that 110v live with neutral return is the system used for the
lighting circuits).

Tha absence of a safety earth on the wall sockets also suggests the
use of the 'safer' bi-phase' distribution system where an earth might
have been considered an 'unnecessary luxury'.

Perhaps you can have a word with one of the native electricians to
get 'the skinny' on their domestic wiring standards.
--
Regards, J B Good

On Wed, 22 Jan 2014 12:34:28 +0100, Martin wrote:

On Tue, 21 Jan 2014 17:06:28 -0000, "Woody" wrote:

"Brian Gaff" wrote in message
...
Probably colour blind.
Whatever next. I used to joke that they made it brown as
it matched the colour of what came out when you ****
yourself after surviving the shock of getting it wrong.

I'd personally like the outside to be rough so I could
still wire a plug.

Of course I predicted this would happen when they started
requiring manufacturers to fit plugs. I notice a lot of
the fitted plugs are just adaptors with a europlug
clamped inside it, meaning presumably that it does not
matter any more.
Brian


Well it doesn't as, if it has a Euro adapter and thus
presumably a Schuko plug inside it, the power switch will be
double pole and the appliance will likely be double
insulated. It is only we Brits (and the Irish who use the
same) who bother about polarity so that we can do it cheap
and only switch the live wire.

You never saw a Dutchman get a shock because the polarity was the wrong way
round on a light bulb fitting. UK electrical fittings and house wiring are
vastly superior to the Dutch equivalent. A standard Dutch house could only use a
maximum of 16 Amps. Most of the sockets in my house have no earth. I lived at
one time in a then new Dutch block of flats, where none of the sockets were
earthed. I know of a case in Italy where a neighbour's dog ****ed on a socket
and died. There are no gates on the sockets small children can and do push bits
of wire into them.

I know the fittings in my house are safe as they can't be accessed
without breaking the physical protection. It was all rewired a few
years ago using whatever electrical standards were going then. My
bathroom has just been rewired with an isolated supply and a leakage
trip. If I stick anything into the 230V socket that provides a leakage
to earth the power goes off instantly.

Steve

--
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