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?

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.

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.

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

--
Please don't feed the trolls

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.

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!

:-)

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.

On 27 Aug 2020 17:22:05 GMT, 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.

We have a system that there are eight flats in the close. The supply
is three phase (three fuses at the door). The flats are 3+3+2 across
the phases. I understand the close next door will be 2+3+3 then 3+2+3
etc to balance the load.

If there is a power cut on one phase, enormous puzzlement results.

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

How do you know you are on the yellow phase? Phases are only identified
in a number or colour sequence, for phase rotation purposes - the
'firing order' of the peaks, in relation to each other.

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.

Scott laid this down on his screen :
We have a system that there are eight flats in the close. The supply
is three phase (three fuses at the door). The flats are 3+3+2 across
the phases. I understand the close next door will be 2+3+3 then 3+2+3
etc to balance the load.

Idea is to minimise the current on the neutral.


If there is a power cut on one phase, enormous puzzlement results.

A lost phase always causes confusion.

In article ,
No Name wrote:
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?

At one time, all houses were fed 3 phase, but only used one. This house
is, for some historic reason, fed with 2 phases.

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

On Thu, 27 Aug 2020 18:49:21 +0100, Harry Bloomfield, Esq.
wrote:

Scott laid this down on his screen :
We have a system that there are eight flats in the close. The supply
is three phase (three fuses at the door). The flats are 3+3+2 across
the phases. I understand the close next door will be 2+3+3 then 3+2+3
etc to balance the load.

Idea is to minimise the current on the neutral.

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

If there is a power cut on one phase, enormous puzzlement results.

A lost phase always causes confusion.

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)?

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.

--
Chris Green
·

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.

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.

On 27/08/2020 18:43:51, Harry Bloomfield wrote:
jon submitted this idea :
My house is on the yellow phase and houses opposite are on blue phase, so
3 phase is piped to our development.

How do you know you are on the yellow phase? Phases are only identified
in a number or colour sequence, for phase rotation purposes - the
'firing order' of the peaks, in relation to each other.

I was thinking the same. But if using accurate timing and a reference it
should be possible to work out which phase you are on.

I'm sure in the network they are well defined. Woe betide an engineer
swapping a couple!

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.

newshound brought next idea :
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).

No, you normally get the three phases, via one three phase meter. The
customer then takes his single phase needs from one or more of those,
plus the neutral. Where a premises was previously split in two with
3-phases to one, single phase to the other, then you might combine them
and have a three phase supply, plus the single phase supply.


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

No, but there are regulations intended to help prevent two phases in
use, coming near to each other, such as 13amp sockets on different
phases. You can have for instance three banks of lights, one on each
phase.

Fredxx has brought this to us :
I was thinking the same. But if using accurate timing and a reference it
should be possible to work out which phase you are on.

To the customer, at the incomer, it doesn't really matter. The customer
might find it handy to know the 'firing order' of the phases, which can
be determined by a phase rotation meter - a tiny three phase motor, or
a neon light/ LED gadget. That way he can ensure his three phase motors
run in the correct direction first go. Otherwise he take a 50/50
chance, connect a motor, then hope it runs the right way. If not, two
of the phases need to be swapped over to correct it - absolutely not
fun, on some of the massive beasts I used to work on, so I made sure
they were right.


I'm sure in the network they are well defined. Woe betide an engineer
swapping a couple!

Chris Green wrote:

Andrew wrote:

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)

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

The point of 3ph EV charging is to get "fast" 22 kW charging ... fill
your tesla in 6 hours instead of 33 hours on a granny cable

On 27/08/2020 18:52, charles wrote:
In article ,
No Name wrote:
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?

At one time, all houses were fed 3 phase, but only used one. This house
is, for some historic reason, fed with 2 phases.

A bit of a generalisation. Mine (18th century) had, like all the
neighbours, a single phase coming in overhead, replaced in the last 30
years with a single phase (one fuse) underground supply to the original
meter.

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?

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.

Scott presented the following explanation :
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?

May not be at zero, but just a few volts of difference. Actual voltage
depends on how well your flat is balanced against other properties or
the other two phases. Plus the supply type. It is rarely a perfect
balance and the voltage will wonder about constantly, as you and
neighbours switch items on and off. Try it and see for yourself.

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

Scott wrote:
On Thu, 27 Aug 2020 18:49:21 +0100, Harry Bloomfield, Esq.
wrote:

Scott laid this down on his screen :
We have a system that there are eight flats in the close. The supply
is three phase (three fuses at the door). The flats are 3+3+2 across
the phases. I understand the close next door will be 2+3+3 then 3+2+3
etc to balance the load.
Idea is to minimise the current on the neutral.

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

Can't find a really good intro.

There are a couple ways to do three-phase. Delta and Wye.

https://en.wikipedia.org/wiki/Delta-wye_transformer

Wye is wired with respect to Neutral. In the top diagram
there, you can see the three phase "loads" are all with
respect to the neutral. Now, on the face of it, the
Wye has some possibilities for single phase operation.
At the potential expense of the balance.

The Delta on the other hand, doesn't use the Neutral, but,
it also doesn't lend itself particularly well to "doing tricks".
Maybe the Delta would be suitable for running three phase
induction motors, where the load on each phase would be
relatively balanced.

Now, as the article above describes, higher levels of your
electrical distribution system, could use Delta during transmission,
then use Delta to Wye transformers at the lower level.

I would say the neutral, is local to the Wye side of the
transformer. You can reference the neutral to earth, for
some sort of grounding strategy I suppose. Maybe one of
the grounding experts knows the practices answer.

Also, the second diagram in that article, shows (neatly),
how a three-tin-can configuration could be built for
Delta-wye.

And there are lots of things transformers don't tolerate
all that well. I'm really surprised flames don't
shoot out of them more often, considering the nature
of loads put on them. A three-phase induction motor,
by comparison, the transformer *loves* that. No harmonics.
No digital crap. Hardly anything to hum about.

Paul

On 27/08/2020 17:50:18, 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?

3-phase is more efficient and since it is rare for a feed to be above
100A per phase, you will need 3-phase if you want to charge your EV and
heat your house with electric.

Soon if they ban gas the only alternative is electrical heating.

In article ,
charles wrote:
In article ,
No Name wrote:
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?

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 parents house, built in the 30s, was too. Was told it was to allow full
house electric heating in the future.

--
*I pretend to work. - they pretend to pay me.

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

On 27/08/2020 19:00, Scott wrote:
On Thu, 27 Aug 2020 18:49:21 +0100, Harry Bloomfield, Esq.
wrote:

Scott laid this down on his screen :
We have a system that there are eight flats in the close. The supply
is three phase (three fuses at the door). The flats are 3+3+2 across
the phases. I understand the close next door will be 2+3+3 then 3+2+3
etc to balance the load.

Idea is to minimise the current on the neutral.

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

Neutral will be "created" at the substation. The substation will have a
three phase transformer in a Y configuration - with the centre of the Y
connected to earth. This centre point becomes the local neutral[1]. The
connection to earth on is used as the return to the grid - i.e. the HV
side is only 3ph, and only the LV side its 3ph + N.

You may then have separate conductors that carry the neutral and earth
to the property. This is a TN-S earthing arrangement. Or more commonly
these days, they use a combined Protective Earth and Neutral (aka PEN)
conductor to the property, and then separate them out into E and N there
art the main cutout. This is a TN-C-S supply.



--
Cheers,

John.

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

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)

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)


--
Cheers,

John.

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

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!

:-)

Old/New
L1 Red/Brown
L2 Yellow/Black
L3 Blue/Grey
N Black/Blue

--
Cheers,

John.

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On Fri, 28 Aug 2020 10:26:17 +0100, John Rumm
wrote:
[snip]

You may then have separate conductors that carry the neutral and earth
to the property. This is a TN-S earthing arrangement. Or more commonly
these days, they use a combined Protective Earth and Neutral (aka PEN)
conductor to the property, and then separate them out into E and N there
art the main cutout. This is a TN-C-S supply.

My flat was built in 1909 and I believe the main wiring was done in
1947 (I think it was lighting only in the front rooms until thenwith
gas for the rest and in the close). In 2019 the cables and cable
heads were upgraded by Optimum (for Scottish Power). At that time the
workers told me that quite a few flats (not mine) had no working
earth.

I told the guys that SP said it would be okay to make mine three phase
free of charge but they were unconvinced :-)

From that timeline, is it possible to infer what the earthing system
would be (a) in 1947 and (b) in 2019? Is there a way of finding out -
by looking - what it is now?

On 28/08/2020 10:47, Scott wrote:
On Fri, 28 Aug 2020 10:26:17 +0100, John Rumm
wrote:
[snip]

You may then have separate conductors that carry the neutral and earth
to the property. This is a TN-S earthing arrangement. Or more commonly
these days, they use a combined Protective Earth and Neutral (aka PEN)
conductor to the property, and then separate them out into E and N there
art the main cutout. This is a TN-C-S supply.

My flat was built in 1909 and I believe the main wiring was done in
1947 (I think it was lighting only in the front rooms until thenwith
gas for the rest and in the close). In 2019 the cables and cable
heads were upgraded by Optimum (for Scottish Power). At that time the
workers told me that quite a few flats (not mine) had no working
earth.

I told the guys that SP said it would be okay to make mine three phase
free of charge but they were unconvinced :-)

From that timeline, is it possible to infer what the earthing system
would be (a) in 1947 and (b) in 2019? Is there a way of finding out -
by looking - what it is now?

Chances are its TN-C-S. You may have a yellow "PME" sticker on the
cutout somewhere.

If you follow through the pictures he

http://wiki.diyfaq.org.uk/index.php/Earthing_Types

You should be able to work out what you have. Note that depending on
area, the local installers may use different brands/styles of head end
cutouts.

Normally on TN-C-S the main earth connection will emerge from the side
of the main cutout. On older TN-S installs its usually easy to see it
connected to the sheath of the incoming supply cable. The tricky one is
new TN-S supplies which use the same equipment and look exactly the same
as a TN-C-S supply - the only difference it the position of links inside
the cutout (which you can't see with the lid on)






--
Cheers,

John.

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

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* 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!

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.

--
*Why isn't there a special name for the back of your knee?

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

On 27/08/2020 20:35, Harry Bloomfield wrote:
newshound brought next idea :
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).

No, you normally get the three phases, via one three phase meter. The
customer then takes his single phase needs from one or more of those,
plus the neutral. Where a premises was previously split in two with
3-phases to one, single phase to the other, then you might combine them
and have a three phase supply, plus the single phase supply.

Out in the country, including round here, I occasionally
see overhead LV on poles ranging from L+N, 2L+?N to 3L+N and
also 3L+N+E


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

No, but there are regulations intended to help prevent two phases in
use, coming near to each other, such as 13amp sockets on different
phases. You can have for instance three banks of lights, one on each phase.

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'.

On 27/08/2020 20:25, Harry Bloomfield wrote:
The neutral will be at or around the earth potential, maybe 20v maximum.

Isn't this how pikeys have managed to steal the neutral bus bar
from a local substation ?.

I simply feel that unless there is an awful coincidence, the fact that every
three premises will be on a different phase would be OK unless the area is
right at the end of a long cable run. Have you ever looked at the mains
waveform, let alone the differences between phases?
Its not a new problem we have factories in my road and after putting in a
beefed up sub station no more problems.
Brian

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"JohnP" wrote in message
. ..
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?