[Dave Plowman (News)]

Got a call from a mate tonight - said his lights had gone dim. ;-)
And so it proved - the volts in the house read 173. 25 year old town house
in a terrace of four in South London. Everybody out in that block - but
got a neighbour on the other side in another block in and checked it there
- 233v.
The services and CU etc were in an 'outhouse' at the front door with no
light - but everything seemed ok. Nothing hot or smoking.
Switching on the heaviest load - the cooker - made only about a volt or
so difference. Tried a fan heater too - the fan only just turned.

They'd been having probs with their boiler recently - and tonight it
doesn't work at all. Wonder if it was low volts causing the original
problem there? Not something you'd expect the average service engineer to
check.

So what's the likely cause? I'd have expected a sub station to feed the
whole area.

--
*I'm planning to be spontaneous tomorrow *

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

[Dave Liquorice[_2_]]

On Thu, 11 Mar 2010 23:24:43 +0000 (GMT), Dave Plowman (News) wrote:

So what's the likely cause? I'd have expected a sub station to feed the
whole area.

The phase feeding that small terrance has a problem. One of the other
phases feeding the other block is OK. With 173 incoming I'd switch
off at the main breaker and call the REC and report it. Some kit may
object by letting out the magic smoke with such a supply. Other kit
will start just draw more current and your cooker/fan heater
experiment indicates that there is plenty of current available, just
that the voltage is low.

--
Cheers
Dave.

[fred]

In article , Dave Plowman (News)
writes
Got a call from a mate tonight - said his lights had gone dim. ;-)
And so it proved - the volts in the house read 173. 25 year old town house
in a terrace of four in South London. Everybody out in that block - but
got a neighbour on the other side in another block in and checked it there
- 233v.
The services and CU etc were in an 'outhouse' at the front door with no
light - but everything seemed ok. Nothing hot or smoking.
Switching on the heaviest load - the cooker - made only about a volt or
so difference. Tried a fan heater too - the fan only just turned.

They'd been having probs with their boiler recently - and tonight it
doesn't work at all. Wonder if it was low volts causing the original
problem there? Not something you'd expect the average service engineer to
check.

So what's the likely cause? I'd have expected a sub station to feed the
whole area.

It's three phase in the street and they rotate the phases through the
street 1-2-3 to balance the load so the neighbour is likely on a
different phase.

The neighbour 3 doors down will likely have the same fault.

Don't know the likely cause but as it's not load dependent it's not
likely to by a high resistance joint anywhere near him. Maybe one of the
ex-distribution network regulars will have a better idea but it's def
one to report to the local regional supplier tomorrow.
--
fred
BBC3, ITV2/3/4, channels going to the DOGs

[Andy Wade]

fred wrote:

It's three phase in the street and they rotate the phases through the
street 1-2-3 to balance the load so the neighbour is likely on a
different phase.

The neighbour 3 doors down will likely have the same fault.

AIUI the phasing usually goes L1-L2-L3-L3-L2-L1-etc., so the pattern
isn't as simple as you suggest. And that's for new estates where all
the services are single-phase and have been connected up at the same
time. In older urban areas you're more likely to have a mixture of 1-ph
and 3-ph connections with different properties having been connected at
different times, so the phasing might best be described as
pseudo-random, notionally balanced...

Don't know the likely cause but as it's not load dependent it's not
likely to by a high resistance joint anywhere near him. Maybe one of the
ex-distribution network regulars will have a better idea but it's def
one to report to the local regional supplier tomorrow.

Don't wait that long, it's a potentially dangerous situation - report it
right away.

--
Andy

[The Wanderer[_2_]]

On Thu, 11 Mar 2010 23:24:43 +0000 (GMT), Dave Plowman (News) wrote:

Got a call from a mate tonight - said his lights had gone dim. ;-)
And so it proved - the volts in the house read 173. 25 year old town house
in a terrace of four in South London. Everybody out in that block - but
got a neighbour on the other side in another block in and checked it there
- 233v.
The services and CU etc were in an 'outhouse' at the front door with no
light - but everything seemed ok. Nothing hot or smoking.
Switching on the heaviest load - the cooker - made only about a volt or
so difference. Tried a fan heater too - the fan only just turned.

They'd been having probs with their boiler recently - and tonight it
doesn't work at all. Wonder if it was low volts causing the original
problem there? Not something you'd expect the average service engineer to
check.

So what's the likely cause? I'd have expected a sub station to feed the
whole area.

Report it straight away. Dunno if it's still the case, but I have the idea
in the back of my mind LEB used to run lots of their lv systems all
interconnected, no open points, so it could be a fuse gone in the closest
s/s with a backfeed coming from a much greater distance.

Why they did it I have no idea, I know fault levels were always a problem
in the London area.


--
The Wanderer

Passion is inversely proportional to the amount of real information
available.

[Tim Watts]

The Wanderer
wibbled on Friday 12 March 2010 07:18

On Thu, 11 Mar 2010 23:24:43 +0000 (GMT), Dave Plowman (News) wrote:

Got a call from a mate tonight - said his lights had gone dim. ;-)
And so it proved - the volts in the house read 173. 25 year old town
house in a terrace of four in South London. Everybody out in that block -
but got a neighbour on the other side in another block in and checked it
there - 233v.
The services and CU etc were in an 'outhouse' at the front door with no
light - but everything seemed ok. Nothing hot or smoking.
Switching on the heaviest load - the cooker - made only about a volt or
so difference. Tried a fan heater too - the fan only just turned.

They'd been having probs with their boiler recently - and tonight it
doesn't work at all. Wonder if it was low volts causing the original
problem there? Not something you'd expect the average service engineer to
check.

So what's the likely cause? I'd have expected a sub station to feed the
whole area.

Report it straight away. Dunno if it's still the case, but I have the idea
in the back of my mind LEB used to run lots of their lv systems all
interconnected, no open points, so it could be a fuse gone in the closest
s/s with a backfeed coming from a much greater distance.

Why they did it I have no idea, I know fault levels were always a problem
in the London area.



Yes - this is good enough reason to call the LEB on their emergency number
which is on the bill, or he

http://www.edfenergy.com/safety-emer...cy/index.shtml

(London area).

Just say lights are remaining dim and you suspect low supply voltage.
They'll be out pretty fast.

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

[Harry Bloomfield[_3_]]

Dave Liquorice has brought this to us :
The phase feeding that small terrance has a problem. One of the other
phases feeding the other block is OK. With 173 incoming I'd switch
off at the main breaker and call the REC and report it. Some kit may
object by letting out the magic smoke with such a supply. Other kit
will start just draw more current and your cooker/fan heater
experiment indicates that there is plenty of current available, just
that the voltage is low.

I would not expect an entire terrace to be on one single phase. The
other block might well be on a completely different supply. Whilst they
do feed single phase premises one phase then the next phase, then the
last one - there is no absolute rule to be relied upon. They might well
have fed two adjacent premises of one phase, then the next two of the
next phase and so on.

Low voltage (a brown out) could simply mean they have had to load shed
in a certain area due to a cable fault, or it could be the supply cable
itself has developed a fault. Another possibility (especially if the
voltage is varying) is that there is a break in the neutral So the load
is simply balancing itself across the phases - which means if you have
lower than spec voltage, someone else has higher than spec voltage.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

[Harry Bloomfield[_3_]]

The Wanderer wrote :
Report it straight away. Dunno if it's still the case, but I have the idea
in the back of my mind LEB used to run lots of their lv systems all
interconnected, no open points, so it could be a fuse gone in the closest
s/s with a backfeed coming from a much greater distance.

It is often wired similar to a ring circuit, where one leg helps
support the other and should one leg fail or need some work, there is
always a second one able to provide for some load capability.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

[Dave Liquorice[_2_]]

On Fri, 12 Mar 2010 17:30:58 GMT, Harry Bloomfield wrote:

I would not expect an entire terrace to be on one single phase.

Mr Plowman wrote "25 year old town house in a terrace of four ..."
not a whole street of two up two downs. B-)

--
Cheers
Dave.

[The Wanderer[_2_]]

On Fri, 12 Mar 2010 17:30:58 GMT, Harry Bloomfield wrote:

Dave Liquorice has brought this to us :
The phase feeding that small terrance has a problem. One of the other
phases feeding the other block is OK. With 173 incoming I'd switch
off at the main breaker and call the REC and report it. Some kit may
object by letting out the magic smoke with such a supply. Other kit
will start just draw more current and your cooker/fan heater
experiment indicates that there is plenty of current available, just
that the voltage is low.

I would not expect an entire terrace to be on one single phase.

I would, especially if the properties were planned for gas CH.

As someone pointed out, the (ESI) planning standard when installing new
services on an estate was R-Y-B-B-Y-R-R-Y-B and so on. I can't remember the
theory now, but this gives better load distribution than R-Y-B-R-Y-B-R-Y-B.

Dunno if it's still the case but 4 way service joints were generally the
maximum, due to the physical limitations of making the connections inside
the joint.

If the houses were gas CH then an individual service could well be looped
to the next property, especially if the properties were mirrored so the
meter positions of adjoining properties are close together. Distribution of
phases along the main then becomes R-R-Y-Y-B-B-B-B-Y-Y-R-R-R-R-Y-Y etc.

This would be most prevalent in high density housing developments. Lower
density, the dwellings are obviously spread out more, and it becomes less
easy to maintain the sequence depending on mains cable routing.

--
The Wanderer

Most organizations are like Russian dolls
- each has another inside.

[ARWadsworth]

"The Wanderer" wrote in message
.. .
On Fri, 12 Mar 2010 17:30:58 GMT, Harry Bloomfield wrote:

Dave Liquorice has brought this to us :
The phase feeding that small terrance has a problem. One of the other
phases feeding the other block is OK. With 173 incoming I'd switch
off at the main breaker and call the REC and report it. Some kit may
object by letting out the magic smoke with such a supply. Other kit
will start just draw more current and your cooker/fan heater
experiment indicates that there is plenty of current available, just
that the voltage is low.

I would not expect an entire terrace to be on one single phase.

I would, especially if the properties were planned for gas CH.

As someone pointed out, the (ESI) planning standard when installing new
services on an estate was R-Y-B-B-Y-R-R-Y-B and so on. I can't remember
the
theory now, but this gives better load distribution than
R-Y-B-R-Y-B-R-Y-B.

Dunno if it's still the case but 4 way service joints were generally the
maximum, due to the physical limitations of making the connections inside
the joint.

If the houses were gas CH then an individual service could well be looped
to the next property, especially if the properties were mirrored so the
meter positions of adjoining properties are close together. Distribution
of
phases along the main then becomes R-R-Y-Y-B-B-B-B-Y-Y-R-R-R-R-Y-Y etc.

Looking at the lights that go off in a powercut on our street it seems to be
R-R-Y-Y-B-B-R-R-Y-Y-B-B etc The incoming supply runs down the garden between
a pair of semis, feeds one cut out and then feeds back across the garden to
the next semis cutout.

Adam

[The Wanderer[_2_]]

On Sat, 13 Mar 2010 09:01:23 GMT, ARWadsworth wrote:


Looking at the lights that go off in a powercut on our street it seems to be
R-R-Y-Y-B-B-R-R-Y-Y-B-B etc The incoming supply runs down the garden between
a pair of semis, feeds one cut out and then feeds back across the garden to
the next semis cutout.

May well be, the sequence I set out was how it was done in Southern.


--
The Wanderer

Better to keep one's mouth shut and be thought a fool
Than to open it and remove all doubt (Mark Twain)

[Dave Plowman (News)]

In article ,
ARWadsworth wrote:
If the houses were gas CH then an individual service could well be
looped to the next property, especially if the properties were
mirrored so the meter positions of adjoining properties are close
together. Distribution of phases along the main then becomes
R-R-Y-Y-B-B-B-B-Y-Y-R-R-R-R-Y-Y etc.

Looking at the lights that go off in a powercut on our street it seems
to be R-R-Y-Y-B-B-R-R-Y-Y-B-B etc The incoming supply runs down the
garden between a pair of semis, feeds one cut out and then feeds back
across the garden to the next semis cutout.

Is the looping normally visible - ie at the riser - or underground?

--
*Also too, never, ever use repetitive redundancies *

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

[ARWadsworth]

"Dave Plowman (News)" wrote in message
...
In article ,
ARWadsworth wrote:
If the houses were gas CH then an individual service could well be
looped to the next property, especially if the properties were
mirrored so the meter positions of adjoining properties are close
together. Distribution of phases along the main then becomes
R-R-Y-Y-B-B-B-B-Y-Y-R-R-R-R-Y-Y etc.

Looking at the lights that go off in a powercut on our street it seems
to be R-R-Y-Y-B-B-R-R-Y-Y-B-B etc The incoming supply runs down the
garden between a pair of semis, feeds one cut out and then feeds back
across the garden to the next semis cutout.

Is the looping normally visible - ie at the riser - or underground?

--
*Also too, never, ever use repetitive redundancies *

Dave Plowman London SW

On my street, 50 year old TNS supplies the looping is done at the
riser/cutout next to the meter. So in my house I have the incoming supply
and then the outgoing one to next door.

Two streets away and slightly older semi detatched houses they use a PME
supply. The supply is run externally and feed 4 houses. The joints on this
are external.

The link below shows one of the joints and the cable linking between 2 semis
if you zoom in. You can see the joint on the left hand semi and also the
cable that runs around the back to feed the other neighbour.

http://tinyurl.com/ycmbfj3

[The Wanderer[_2_]]

On Sat, 13 Mar 2010 09:37:58 +0000 (GMT), Dave Plowman (News) wrote:

In article ,
ARWadsworth wrote:
If the houses were gas CH then an individual service could well be
looped to the next property, especially if the properties were
mirrored so the meter positions of adjoining properties are close
together. Distribution of phases along the main then becomes
R-R-Y-Y-B-B-B-B-Y-Y-R-R-R-R-Y-Y etc.

Looking at the lights that go off in a powercut on our street it seems
to be R-R-Y-Y-B-B-R-R-Y-Y-B-B etc The incoming supply runs down the
garden between a pair of semis, feeds one cut out and then feeds back
across the garden to the next semis cutout.

Is the looping normally visible - ie at the riser - or underground?

Usually from the main fuse.


--
The Wanderer

Most organizations are like Russian dolls
- each has another inside.

[Dave Plowman (News)]

In article ,
ARWadsworth wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
ARWadsworth wrote:
If the houses were gas CH then an individual service could well be
looped to the next property, especially if the properties were
mirrored so the meter positions of adjoining properties are close
together. Distribution of phases along the main then becomes
R-R-Y-Y-B-B-B-B-Y-Y-R-R-R-R-Y-Y etc.

Looking at the lights that go off in a powercut on our street it seems
to be R-R-Y-Y-B-B-R-R-Y-Y-B-B etc The incoming supply runs down the
garden between a pair of semis, feeds one cut out and then feeds back
across the garden to the next semis cutout.

Is the looping normally visible - ie at the riser - or underground?

On my street, 50 year old TNS supplies the looping is done at the
riser/cutout next to the meter. So in my house I have the incoming
supply and then the outgoing one to next door.

Two streets away and slightly older semi detatched houses they use a PME
supply. The supply is run externally and feed 4 houses. The joints on
this are external.

The link below shows one of the joints and the cable linking between 2
semis if you zoom in. You can see the joint on the left hand semi and
also the cable that runs around the back to feed the other neighbour.

http://tinyurl.com/ycmbfj3

Right - this one wasn't - only the one cable to the riser. But was the end
of the block.

--
*Whatever kind of look you were going for, you missed.

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

[Andy Burns[_7_]]

ARWadsworth wrote:

http://tinyurl.com/ycmbfj3

I didn't know Premier Inn stooped so low that they use semi-detached
bunglalows these days?

http://tinyurl.com/premier-bungalow

[Andy Burns[_7_]]

Andy Burns wrote:

I didn't know Premier Inn stooped so low that they use semi-detached
bunglalows these days?

http://tinyurl.com/premier-bungalow

Heh, looks like it should be Maple Rd, Tankersley

[tony sayer]

So what's the likely cause? I'd have expected a sub station to feed the
whole area.

Report it straight away. Dunno if it's still the case, but I have the idea
in the back of my mind LEB used to run lots of their lv systems all
interconnected, no open points, so it could be a fuse gone in the closest
s/s with a backfeed coming from a much greater distance.

Why they did it I have no idea, I know fault levels were always a problem
in the London area.



Yes - this is good enough reason to call the LEB on their emergency number
which is on the bill, or he

http://www.edfenergy.com/safety-emer...cy/index.shtml

(London area).

Just say lights are remaining dim and you suspect low supply voltage.
They'll be out pretty fast.



Near here a bit out in the sticks a man lost his supply, well almost
lost it the neutral had fallen off the distribution line and was laying
on the damp grass and he had some rather dim lighting the live sort of
returning to the transformer that way....

He thought if it was a bit wetter then it might be brighter as well..
water sorta conducts. So it was watered and the lights did indeed get a
lot brighter and it was like this several days till I saw him and almost
shat myself with what had happened.. And so did the blokes from the
power company when they turned up;!....
--
Tony Sayer

[James Salisbury[_3_]]

tony sayer wrote:
So what's the likely cause? I'd have expected a sub station to feed the
whole area.
Report it straight away. Dunno if it's still the case, but I have the idea
in the back of my mind LEB used to run lots of their lv systems all
interconnected, no open points, so it could be a fuse gone in the closest
s/s with a backfeed coming from a much greater distance.

Why they did it I have no idea, I know fault levels were always a problem
in the London area.


Yes - this is good enough reason to call the LEB on their emergency number
which is on the bill, or he

http://www.edfenergy.com/safety-emer...cy/index.shtml

(London area).

Just say lights are remaining dim and you suspect low supply voltage.
They'll be out pretty fast.



Near here a bit out in the sticks a man lost his supply, well almost
lost it the neutral had fallen off the distribution line and was laying
on the damp grass and he had some rather dim lighting the live sort of
returning to the transformer that way....

He thought if it was a bit wetter then it might be brighter as well..
water sorta conducts. So it was watered and the lights did indeed get a
lot brighter and it was like this several days till I saw him and almost
shat myself with what had happened.. And so did the blokes from the
power company when they turned up;!....
Hi,
When I was on holiday in Canada, I saw lots of installations with only
one HV line providing power out in the sticks between Quebec and
Montreal... must have been earth return single phase.

[tony sayer]

In article , James Salisbury
nntp.dsl.pipex.com@?.? scribeth thus
tony sayer wrote:
So what's the likely cause? I'd have expected a sub station to feed the
whole area.
Report it straight away. Dunno if it's still the case, but I have the idea
in the back of my mind LEB used to run lots of their lv systems all
interconnected, no open points, so it could be a fuse gone in the closest
s/s with a backfeed coming from a much greater distance.

Why they did it I have no idea, I know fault levels were always a problem
in the London area.


Yes - this is good enough reason to call the LEB on their emergency number
which is on the bill, or he

http://www.edfenergy.com/safety-emer...cy/index.shtml

(London area).

Just say lights are remaining dim and you suspect low supply voltage.
They'll be out pretty fast.



Near here a bit out in the sticks a man lost his supply, well almost
lost it the neutral had fallen off the distribution line and was laying
on the damp grass and he had some rather dim lighting the live sort of
returning to the transformer that way....

He thought if it was a bit wetter then it might be brighter as well..
water sorta conducts. So it was watered and the lights did indeed get a
lot brighter and it was like this several days till I saw him and almost
shat myself with what had happened.. And so did the blokes from the
power company when they turned up;!....
Hi,
When I was on holiday in Canada, I saw lots of installations with only
one HV line providing power out in the sticks between Quebec and
Montreal... must have been earth return single phase.


Yes I did read about that somewhere, seems the earth at that sort of
voltage and DC was quite suitable for that purpose....

--
Tony Sayer

[James Salisbury[_3_]]

tony sayer wrote:
In article , James Salisbury
nntp.dsl.pipex.com@?.? scribeth thus
tony sayer wrote:
So what's the likely cause? I'd have expected a sub station to feed the
whole area.
Report it straight away. Dunno if it's still the case, but I have the idea
in the back of my mind LEB used to run lots of their lv systems all
interconnected, no open points, so it could be a fuse gone in the closest
s/s with a backfeed coming from a much greater distance.

Why they did it I have no idea, I know fault levels were always a problem
in the London area.


Yes - this is good enough reason to call the LEB on their emergency number
which is on the bill, or he

http://www.edfenergy.com/safety-emer...cy/index.shtml

(London area).

Just say lights are remaining dim and you suspect low supply voltage.
They'll be out pretty fast.


Near here a bit out in the sticks a man lost his supply, well almost
lost it the neutral had fallen off the distribution line and was laying
on the damp grass and he had some rather dim lighting the live sort of
returning to the transformer that way....

He thought if it was a bit wetter then it might be brighter as well..
water sorta conducts. So it was watered and the lights did indeed get a
lot brighter and it was like this several days till I saw him and almost
shat myself with what had happened.. And so did the blokes from the
power company when they turned up;!....
Hi,
When I was on holiday in Canada, I saw lots of installations with only
one HV line providing power out in the sticks between Quebec and
Montreal... must have been earth return single phase.


Yes I did read about that somewhere, seems the earth at that sort of
voltage and DC was quite suitable for that purpose....

Hi,
This was AC..

[James Salisbury[_3_]]

tony sayer wrote:
In article , James Salisbury
nntp.dsl.pipex.com@?.? scribeth thus
tony sayer wrote:
So what's the likely cause? I'd have expected a sub station to feed the
whole area.
Report it straight away. Dunno if it's still the case, but I have the idea
in the back of my mind LEB used to run lots of their lv systems all
interconnected, no open points, so it could be a fuse gone in the closest
s/s with a backfeed coming from a much greater distance.

Why they did it I have no idea, I know fault levels were always a problem
in the London area.


Yes - this is good enough reason to call the LEB on their emergency number
which is on the bill, or he

http://www.edfenergy.com/safety-emer...cy/index.shtml

(London area).

Just say lights are remaining dim and you suspect low supply voltage.
They'll be out pretty fast.


Near here a bit out in the sticks a man lost his supply, well almost
lost it the neutral had fallen off the distribution line and was laying
on the damp grass and he had some rather dim lighting the live sort of
returning to the transformer that way....

He thought if it was a bit wetter then it might be brighter as well..
water sorta conducts. So it was watered and the lights did indeed get a
lot brighter and it was like this several days till I saw him and almost
shat myself with what had happened.. And so did the blokes from the
power company when they turned up;!....
Hi,
When I was on holiday in Canada, I saw lots of installations with only
one HV line providing power out in the sticks between Quebec and
Montreal... must have been earth return single phase.


Yes I did read about that somewhere, seems the earth at that sort of
voltage and DC was quite suitable for that purpose....

This was AC.....

[Dave Liquorice[_2_]]

On Sat, 13 Mar 2010 23:53:35 +0000, tony sayer wrote:

Yes I did read about that somewhere, seems the earth at that sort of
voltage and DC was quite suitable for that purpose....

The impedance of The Earth is effectively zero, making good
connection to it is the tricky bit. In the days of trams and traction
power return via the tracks they initially weren't very bothered
about making sure the tracks had decent electrical continuity. The up
shot being that the traction power would find the path of least
resistance, sometimes down the lead sheaths of telephone cables
buried near by until the GPO started making a fuss.

--
Cheers
Dave.

[Bob Eager]

On Sun, 14 Mar 2010 12:40:40 +0000, Dave Liquorice wrote:

On Sat, 13 Mar 2010 23:53:35 +0000, tony sayer wrote:

Yes I did read about that somewhere, seems the earth at that sort of
voltage and DC was quite suitable for that purpose....

The impedance of The Earth is effectively zero, making good connection
to it is the tricky bit. In the days of trams and traction power return
via the tracks they initially weren't very bothered about making sure
the tracks had decent electrical continuity. The up shot being that the
traction power would find the path of least resistance, sometimes down
the lead sheaths of telephone cables buried near by until the GPO
started making a fuss.

http://www.urban75.org/railway/brighton-sea-railway.htm

Read the bit under 'The Tram'...!



--
Use the BIG mirror service in the UK:
http://www.mirrorservice.org

[James Salisbury[_3_]]

Dave Liquorice wrote:
On Sat, 13 Mar 2010 23:53:35 +0000, tony sayer wrote:

Yes I did read about that somewhere, seems the earth at that sort of
voltage and DC was quite suitable for that purpose....

The impedance of The Earth is effectively zero, making good
connection to it is the tricky bit. In the days of trams and traction
power return via the tracks they initially weren't very bothered
about making sure the tracks had decent electrical continuity. The up
shot being that the traction power would find the path of least
resistance, sometimes down the lead sheaths of telephone cables
buried near by until the GPO started making a fuss.

It is still a modern problem, the CERN tunnels do suffer from surface
traction current ingress....

James

[Andy Burns[_7_]]

Bob Eager wrote:

http://www.urban75.org/railway/brighton-sea-railway.htm

missing the "L" from .html

[Bob Eager]

On Sun, 14 Mar 2010 13:15:19 +0000, Andy Burns wrote:

Bob Eager wrote:

http://www.urban75.org/railway/brigh...a-railway.html

missing the "L" from .html

Oops, thanks.

People used to go bathing near a running one because they heard the
electricity was good for them...



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[dennis@home]

"James Salisbury" nntp.dsl.pipex.com wrote in message
...
Dave Liquorice wrote:
On Sat, 13 Mar 2010 23:53:35 +0000, tony sayer wrote:

Yes I did read about that somewhere, seems the earth at that sort of
voltage and DC was quite suitable for that purpose....

The impedance of The Earth is effectively zero, making good
connection to it is the tricky bit. In the days of trams and traction
power return via the tracks they initially weren't very bothered
about making sure the tracks had decent electrical continuity. The up
shot being that the traction power would find the path of least
resistance, sometimes down the lead sheaths of telephone cables
buried near by until the GPO started making a fuss.

It is still a modern problem, the CERN tunnels do suffer from surface
traction current ingress....

You would have thought they would have put mesh in the walls to act as a
faraday cage.