On 27/08/2020 18:52, charles wrote:

At one time, all houses were fed 3 phase, but only used one. This house
is, for some historic reason, fed with 2 phases.
My family home (a new build from 1966) had (still does) two phases. It
was because it used storage heating, so it has four fuse boxes, four
ELCBs, and four meters !
On Peak Ph 1/Off Peak Ph /On Peak Ph2/Off Peak Ph2.Â* All that lot takes
up a monumental amount of space on the hall wall. My dad built a cabinet
around it all.

My dad wanted gas central heating etc. Asked Southern Gas whether there
was a gas main in the road. 'No chance, and probably never' he was told,
so he went ahead with electric heating. 6 months later, the gas board
turn up in the village and dig up the main road to install a gas main.

In article ,
Dave Plowman (News) wrote:
In article ,
No Name wrote:
Old/New
L1 Red/Brown
L2 Yellow/Black
L3 Blue/Grey
N Black/Blue


the swapping of blue and black between the old and new colours must be
confusing and responsible for a few bangs!

Anyone incapable of transposing the colours really shouldn't be playing
with electricity, let alone 3 phase.

However, troubles can arise when there are modern additions to an older
installation. "is that Black (or Blue) a phase or a neutral?"

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On 28/08/2020 13:54, Mark Carver wrote:
On 27/08/2020 18:52, charles wrote:

At one time, all houses were fed 3 phase, but only used one.Â* This house
is, for some historic reason, fed with 2 phases.
My family home (a new build from 1966) had (still does) two phases. It
was because it used storage heating, so it has four fuse boxes, four
ELCBs, and four meters !
On Peak Ph 1/Off Peak Ph /On Peak Ph2/Off Peak Ph2.Â* All that lot takes
up a monumental amount of space on the hall wall. My dad built a cabinet
around it all.


Handy if he buys an electric car though.

On 28/08/2020 14:19, Andrew wrote:
On 28/08/2020 13:54, Mark Carver wrote:
On 27/08/2020 18:52, charles wrote:

At one time, all houses were fed 3 phase, but only used one. This house
is, for some historic reason, fed with 2 phases.
My family home (a new build from 1966) had (still does) two phases.
It was because it used storage heating, so it has four fuse boxes,
four ELCBs, and four meters !
On Peak Ph 1/Off Peak Ph /On Peak Ph2/Off Peak Ph2.Â* All that lot
takes up a monumental amount of space on the hall wall. My dad built
a cabinet around it all.


Handy if he buys an electric car though

Difficult now, as I spread him all over a Sussex beach two years ago;
but otherwise, yes !

In article ,
charles wrote:
In article ,
Dave Plowman (News) wrote:
In article ,
No Name wrote:
Old/New
L1 Red/Brown
L2 Yellow/Black
L3 Blue/Grey
N Black/Blue


the swapping of blue and black between the old and new colours must be
confusing and responsible for a few bangs!

Anyone incapable of transposing the colours really shouldn't be playing
with electricity, let alone 3 phase.

However, troubles can arise when there are modern additions to an older
installation. "is that Black (or Blue) a phase or a neutral?"

Then check before doing anything? A simple volt meter will tell you if it
is a 'phase or neutral'.

--
*If you try to fail and succeed, which have you done? *

Dave Plowman London SW
To e-mail, change noise into sound.

on 28/08/2020, Andrew supposed :
My brother and his 2nd wife lived next door in the EOT and 1st house in
of a terrace. They knocked through into one house and even after having
work done by an electrician there are no warnings about phases even
though they still have two meters and two 'fuseboxes'.

Are they on different phases, you did not make that clear? Two meters
might or might not suggest two phases.

I would want to check, and be sure.

Paul formulated the question :
There are a couple ways to do three-phase. Delta and Wye.

In the Uk called Star and Delta.

On Fri, 28 Aug 2020 14:38:42 +0100, Mark Carver
wrote:

On 28/08/2020 14:19, Andrew wrote:
On 28/08/2020 13:54, Mark Carver wrote:
On 27/08/2020 18:52, charles wrote:

At one time, all houses were fed 3 phase, but only used one. This house
is, for some historic reason, fed with 2 phases.
My family home (a new build from 1966) had (still does) two phases.
It was because it used storage heating, so it has four fuse boxes,
four ELCBs, and four meters !
On Peak Ph 1/Off Peak Ph /On Peak Ph2/Off Peak Ph2.* All that lot
takes up a monumental amount of space on the hall wall. My dad built
a cabinet around it all.


Handy if he buys an electric car though

Difficult now, as I spread him all over a Sussex beach two years ago;
but otherwise, yes !

That was my thought too. Sorry to hear that.

On 28/08/2020 12:18, No Name wrote:
On 28/08/2020 10:37, John Rumm wrote:
On 27/08/2020 18:38, No Name wrote:
On 27/08/2020 18:16, jon wrote:
On Thu, 27 Aug 2020 16:50:18 +0000, JohnP wrote:

Does anyone think that 3 phase may become a practial proposition four
houses to enable better electric car charging in the future? Is there
really much more involved in the scheme of things for new build areas?

My house is on the yellow phase and houses opposite are on blue
phase, so
3 phase is piped to our development.


Whats that in new money please?

I am too young to know the old phase colours, I only know the new
phase colours!

:-)

Â*Â*Â* Old/New
L1 Red/Brown
L2 Yellow/Black
L3 Blue/Grey
NÂ* Black/Blue


the swapping of blue and black between the old and new colours must be
confusing and responsible for a few bangs!

You can usually tell from the context - but there are some cases its a
problem - like a conduit full of singles with both three and single
phase circuits.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In message
John Rumm wrote:

On 27/08/2020 20:54, Scott wrote:
On Thu, 27 Aug 2020 20:25:37 +0100, Harry Bloomfield, Esq.
wrote:

Scott brought next idea :
A wholly ignorant question but how does the neutral work? Is it
another earth or is it returned to the substation?

The neutral will be at or around the earth potential, maybe 20v
maximum.

It is there to balance up the differences in the loading of individual
phases. One way to look at it, is a street of houses, where each house
is sequentially on phases 1,2,3 then 1,2,3 and so on all along the
street. Adjacent houses will be across three different phases and if
reasonably balanced loading between the three, there will be little
actual current flowing in the neutral.

Sometimes the sequence can be 1,1, 2,2, 3,3, 1,1 and so on. I share the
same phase with the other half my semi.

Suppliers like a nicely balanced load across the three phases, because
it is more efficient.

Between phases the voltage is 415, between any phase and earth/neutral
it is 240v.

Current will flow from say house 21 on phase 1, to 23 on phase 2, then
to 25 on phase 3 rinse and repeat at 50 hertz, but the neutral acts as
the return linking the three houses. That assumes all three houses are
each consuming the same current. If not, then the neutral has to carry
the return current to a more distant house, to balance itself against.

If you compare the three phases to a three cylinder engine, they are
out of phase with each other by 120 degrees - one phase will be
sucking, one blowing and the last one doing neither.

That over simplifies it, it might seem complex, but the basic idea is
simple once you grasp it.

Thanks. I saw a video that related the phases to a magnet and a
clockface: https://youtu.be/iMn7dq7B1oo

Does this mean the neutral within the flat may not be zero volts?


Neutral will be close to earth potential (it is joined to it
*somewhere*), but may not be exactly. In any given property its carrying
the same load as the live so since it does not have zero resistance it
will have some voltage drop on it. So at point of use it may be rise a
bit away from true earth. (and the live will fall a bit toward it)

Neutral is connected to earth via a very large one ohm resitor at the
generating station.
The resistor is checked periodically to ensure it is one ohm.

PME (TN-C-S) supplies will suffer less from this since the neutral is
separated from the earth at the property, and there are multiple
connections to earth along the way.

(its the main reason that neutral is considered to be a live wire)




--
John Bryan

On 28/08/2020 15:34, Scott wrote:
On Fri, 28 Aug 2020 14:38:42 +0100, Mark Carver

Handy if he buys an electric car though

Difficult now, as I spread him all over a Sussex beach two years ago;
but otherwise, yes !

That was my thought too. Sorry to hear that.

He didn't realise it, but our house was clearly way ahead of its time in
1966 !


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

On 28/08/2020 18:52, John Bryan wrote:
In message
John Rumm wrote:

On 27/08/2020 20:54, Scott wrote:
On Thu, 27 Aug 2020 20:25:37 +0100, Harry Bloomfield, Esq.
wrote:

Scott brought next idea :
A wholly ignorant question but how does the neutral work? Is it
another earth or is it returned to the substation?

The neutral will be at or around the earth potential, maybe 20v
maximum.

It is there to balance up the differences in the loading of individual
phases. One way to look at it, is a street of houses, where each house
is sequentially on phases 1,2,3 then 1,2,3 and so on all along the
street. Adjacent houses will be across three different phases and if
reasonably balanced loading between the three, there will be little
actual current flowing in the neutral.

Sometimes the sequence can be 1,1, 2,2, 3,3, 1,1 and so on. I share the
same phase with the other half my semi.

Suppliers like a nicely balanced load across the three phases, because
it is more efficient.

Between phases the voltage is 415, between any phase and earth/neutral
it is 240v.

Current will flow from say house 21 on phase 1, to 23 on phase 2, then
to 25 on phase 3 rinse and repeat at 50 hertz, but the neutral acts as
the return linking the three houses. That assumes all three houses are
each consuming the same current. If not, then the neutral has to carry
the return current to a more distant house, to balance itself against.

If you compare the three phases to a three cylinder engine, they are
out of phase with each other by 120 degrees - one phase will be
sucking, one blowing and the last one doing neither.

That over simplifies it, it might seem complex, but the basic idea is
simple once you grasp it.

Thanks. I saw a video that related the phases to a magnet and a
clockface: https://youtu.be/iMn7dq7B1oo

Does this mean the neutral within the flat may not be zero volts?


Neutral will be close to earth potential (it is joined to it
*somewhere*), but may not be exactly. In any given property its carrying
the same load as the live so since it does not have zero resistance it
will have some voltage drop on it. So at point of use it may be rise a
bit away from true earth. (and the live will fall a bit toward it)

Neutral is connected to earth via a very large one ohm resitor at the
generating station.
The resistor is checked periodically to ensure it is one ohm.

Do they need a neutral at the generating station?


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Chris Green wrote:
Andrew wrote:
On 27/08/2020 17:50, JohnP wrote:
Does anyone think that 3 phase may become a practial proposition four
houses to enable better electric car charging in the future? Is there
really much more involved in the scheme of things for new build areas?

A 1974-built house near me seems to have had a 3-phase
charger installed (it looks a lot bigger than the normal
type 2 car chargers) and EDF closed the road while they dug
a trench, presumably because there was a higher capacity
cable on the other side. Houses built on both sides of the
road.

Surely the whole point of using 3-phase would be that it was *smaller*
than the same power in single phase.


Three transformers working for you.

https://hec-r.s3.amazonaws.com/Site/...s/foe/tdtt.jpg

And the charger is expected to extract equal amounts of
power from each tin can.

The tin cans themselves come in different capacities.
The transformer is relatively small and sits in the bottom
of the can. The rest is oil and convection cooling.
Like an inkjet cartridge, they can fit a different sized
chunk of transformer iron in the bottom, as there is
lots of room (normally reserved for the volume of oil
desired). Inkjet cartridges have a lot of wasted space
too.

If you go to the maintenance yard here, there's a section
filled with spare tin cans. Hundreds of them. If you plan
on using more electricity than at present, here they will
do the can upgrade free of charge (because it's good for
business). They only get upset, if you ask for more power
than the distribution in the neighborhood can handle.

It will be interesting to see what happens when more BEV
cars show up. How will they handle the upgrades, and
who will get stuck with a fat bill of some sort ? I can't imagine
free lunches being offered forever.

We don't have three phase in subdivisions here, so the
three-can thing is academic. And the piddly charger here
won't be as good as yours.

Paul

In message
John Rumm wrote:

On 28/08/2020 18:52, John Bryan wrote:
In message
John Rumm wrote:

On 27/08/2020 20:54, Scott wrote:
On Thu, 27 Aug 2020 20:25:37 +0100, Harry Bloomfield, Esq.
wrote:

Scott brought next idea :
A wholly ignorant question but how does the neutral work? Is it
another earth or is it returned to the substation?

The neutral will be at or around the earth potential, maybe 20v
maximum.

It is there to balance up the differences in the loading of individual
phases. One way to look at it, is a street of houses, where each house
is sequentially on phases 1,2,3 then 1,2,3 and so on all along the
street. Adjacent houses will be across three different phases and if
reasonably balanced loading between the three, there will be little
actual current flowing in the neutral.

Sometimes the sequence can be 1,1, 2,2, 3,3, 1,1 and so on. I share the
same phase with the other half my semi.

Suppliers like a nicely balanced load across the three phases, because
it is more efficient.

Between phases the voltage is 415, between any phase and earth/neutral
it is 240v.

Current will flow from say house 21 on phase 1, to 23 on phase 2, then
to 25 on phase 3 rinse and repeat at 50 hertz, but the neutral acts as
the return linking the three houses. That assumes all three houses are
each consuming the same current. If not, then the neutral has to carry
the return current to a more distant house, to balance itself against.

If you compare the three phases to a three cylinder engine, they are
out of phase with each other by 120 degrees - one phase will be
sucking, one blowing and the last one doing neither.

That over simplifies it, it might seem complex, but the basic idea is
simple once you grasp it.

Thanks. I saw a video that related the phases to a magnet and a
clockface: https://youtu.be/iMn7dq7B1oo

Does this mean the neutral within the flat may not be zero volts?


Neutral will be close to earth potential (it is joined to it
*somewhere*), but may not be exactly. In any given property its carrying
the same load as the live so since it does not have zero resistance it
will have some voltage drop on it. So at point of use it may be rise a
bit away from true earth. (and the live will fall a bit toward it)

Neutral is connected to earth via a very large one ohm resitor at the
generating station.
The resistor is checked periodically to ensure it is one ohm.

Do they need a neutral at the generating station?

No it is provided for the distribution system.
The site electrics will no doubt have a neutral for lighting and single
phase stuff but it is ultimately connected to the generator earth.
I once measured the the neutral to earth voltage at 2.6volts after
generating a spark when reconnecting an earth lead to a metal chassis.


--
John Bryan

Bob Eager Wrote in message:
On Thu, 27 Aug 2020 20:01:43 +0100, newshound wrote:

On 27/08/2020 19:30, Scott wrote:
On Thu, 27 Aug 2020 18:46:57 +0100, Harry Bloomfield, Esq.
wrote:

No Name expressed precisely :
On 27/08/2020 18:22, Tim+ wrote:
jon wrote:
On Thu, 27 Aug 2020 16:50:18 +0000, JohnP wrote:

Does anyone think that 3 phase may become a practial proposition
four houses to enable better electric car charging in the future?
Is there really much more involved in the scheme of things for new
build areas?

My house is on the yellow phase and houses opposite are on blue
phase, so 3 phase is piped to our development.

I would imagine that all three phases pass down virtually every
street.
Only properties requiring three phases will be supplied with it
though.

Tim

What would the criteria be for a domestic house to have a 3 phase
supply?
S.

An high enough demand, or a customer willing to pay the cost of
installing it and the higher standing charge.

Would you get a lower unit charge? I think I saw a suggestion that
three phase is more efficient.

Are there any special rules about balancing the phases (within one
property)?

Might be wrong, but I thought normally 3 phase on a property was only
fed to three phase loads, with a separate single phase supply for other
loads. (At least, that is how it is at a very small commercial property
that I know).

Certainly running different phases "nearby" is deprecated because of the
higher phase to phase voltage.

Yes. SWMBO used to work in a 'posh' grammar school. They had a Linux room
for the A level computing students. It was fed off one phase.

They needed an extra mains outlet in one corner, so the electricians
drilled a hole in the wall from a socket in the next room, and added a
spur. On a different phase.

I forget how she found out, but there were no markings and two of the
sockets, on different phases, were about a metre apart.

She complained and was labelled a troublemaker. She was 'advised to
leave' shortly afterwards.



--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor


I used to install kit in betting shops for SiS. On one job a new
shop had been created by knocking through the party wall between
two units.
The satellite receiver and decoder were in one half and the
distribution amps and text computer and multiple screens in the
other. There was an almighty 50Hz hum on the sound and hum-bars
on the screens, it was obvious why but no one else had twigged.

I cured it for the time being with an extension cable.

My sister used to teach in a small very exclusive private girls'
school. They were doing some classroom renovations and discovered
a boarded-up room between two classrooms amongst the chemistry
glassware that was in there was a large beaker of a dull looking
metallic substance half covered in oil. They called the fire
brigade.
--

%Profound_observation%


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 29/08/2020 02:47, Paul wrote:
Chris Green wrote:
Andrew wrote:
On 27/08/2020 17:50, JohnP wrote:
Does anyone think that 3 phase may become a practial proposition four
houses to enable better electric car charging in the future? Is there
really much more involved in the scheme of things for new build areas?

A 1974-built house near me seems to have had a 3-phase
charger installed (it looks a lot bigger than the normal
type 2 car chargers) and EDF closed the road while they dug
a trench, presumably because there was a higher capacity
cable on the other side. Houses built on both sides of the
road.

Surely the whole point of using 3-phase would be that it was *smaller*
than the same power in single phase.


Three transformers working for you.

https://hec-r.s3.amazonaws.com/Site/...s/foe/tdtt.jpg


And the charger is expected to extract equal amounts of
power from each tin can.

The tin cans themselves come in different capacities.
The transformer is relatively small and sits in the bottom
of the can. The rest is oil and convection cooling.
Like an inkjet cartridge, they can fit a different sized
chunk of transformer iron in the bottom, as there is
lots of room (normally reserved for the volume of oil
desired). Inkjet cartridges have a lot of wasted space
too.

Same principles apply here, although in urban location a substation
(i.e. big transformer[1]) will tend to supply a whole area, so loads
(mostly single phase) will tend to be spread between phases. If you are
a three phase user, then again you will be typically sharing a
substation level transformer with many others, so in sum respects its
less important to ballance the consumption between phases since your
load is mixed with that of others.

[1]
https://emfinspections.co.uk/substat...-need-to-know/

More rural locations with overhead supplies will tend to hole pole
mounted transformers, although the use of spearate cans for each phase
is not usuaully seen, and whole 3ph transformers more common:

https://www.alamy.com/stock-photo-po...-30853562.html

Something similar to the above would power say 10 - 20 homes and a few
small businesses.

It will be interesting to see what happens when more BEV
cars show up. How will they handle the upgrades, and
who will get stuck with a fat bill of some sort ? I can't imagine
free lunches being offered forever.

Its not only the local supply, but the actual generating capacity, that
will be tested if/when there is a significant move from petrol/diesel to
electric.


We don't have three phase in subdivisions here, so the
three-can thing is academic. And the piddly charger here
won't be as good as yours.

I expect most home chargers will be in the 5 to 7kW range anyway, since
that will run from a single phase domestic supply without using too much
of the total capacity. (modern installs are usually 24kW - 240V @ 100A),
in older places 80, 60, and even 40A is not uncommon.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 28/8/20 5:56 am, Scott wrote:
On Thu, 27 Aug 2020 19:58:27 +0100, Harry Bloomfield, Esq.
wrote:

Scott formulated on Thursday :
Would you get a lower unit charge? I think I saw a suggestion that
three phase is more efficient.

Are there any special rules about balancing the phases (within one
property)?

You would need to ask a potential supplier those questions, it can vary
on supplier and area.

Mere curiosity. There is no way I could justify a three phase supply.


Things like large aircon some heating or workshop machinery requiring
three phase even large cookers are a good enough reason.

On 28/08/2020 10:35, John Rumm wrote:
Neutral will be close to earth potential (it is joined to it
*somewhere*), but may not be exactly. In any given property its carrying
the same load as the live so since it does not have zero resistance it
will have some voltage drop on it. So at point of use it may be rise a
bit away from true earth. (and the live will fall a bit toward it)

I recall being very puzzled when I was young when I found my parent's
house had 15V E-N (a lot, yes?) and yet the same voltage L-N as L-E.

Now I just think the neutral was jumping around a lot out of phase with
the live.


Andy
--
The drive was nearly 200yards long, and I have no idea where the
substation was. I just looked it up on Google Earth - the empty field
next door is now a wood!

On 27/08/2020 20:25, Harry Bloomfield wrote:
Scott brought next idea :
A wholly ignorant question but how does the neutral work?* Is it
another earth or is it returned to the substation?

The neutral conductor goes back to substation and is connected to the
star point (Y) of the distribution transformer.

Snipped