Hi

A surprising one this - but what size cable would you use to connect a
house?

It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.

I'm trying to convince my friend that he'd be far better off letting
EON connect him to their new transformer (over 350m away across
fields), rather than do it himself. I'm slightly concerned that the
electrician who has quoted 50mm2 4-core, plus 35mm2 G/Y earth, might
be out of his depth too! It's a hell of a lot of cable to pull through
350m of (already laid) conduit!

My humble opinion is that, unless he goes up a size or two in cable,
he will be storing up a whole load of voltage drop problems for the
future, which won't be an issue if it's EON's cable. Plus if he ever
falls out with the farmers who own the fields, he might end up with
some serious way-leave problems. EON etc. have powers to enforce way-
leaves in certain situations I believe.

Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.

LGF

On 19/07/2011 13:10, legrandfromage wrote:
Hi

A surprising one this - but what size cable would you use to connect a
house?

It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.

I'm trying to convince my friend that he'd be far better off letting
EON connect him to their new transformer (over 350m away across
fields), rather than do it himself. I'm slightly concerned that the
electrician who has quoted 50mm2 4-core, plus 35mm2 G/Y earth, might
be out of his depth too! It's a hell of a lot of cable to pull through
350m of (already laid) conduit!

My humble opinion is that, unless he goes up a size or two in cable,
he will be storing up a whole load of voltage drop problems for the
future, which won't be an issue if it's EON's cable. Plus if he ever
falls out with the farmers who own the fields, he might end up with
some serious way-leave problems. EON etc. have powers to enforce way-
leaves in certain situations I believe.

Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.

Is this in France?

In the UK, isn't the wiring up to the meter the leccy company's problem
anyway, ie DIY that part isn't an option?

On Jul 19, 1:29*pm, Clive George wrote:
On 19/07/2011 13:10, legrandfromage wrote:



Hi

A surprising one this - but what size cable would you use to connect a
house?

It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.

I'm trying to convince my friend that he'd be far better off letting
EON connect him to their new transformer (over 350m away across
fields), rather than do it himself. I'm slightly concerned that the
electrician who has quoted 50mm2 4-core, plus 35mm2 G/Y earth, might
be out of his depth too! It's a hell of a lot of cable to pull through
350m of (already laid) conduit!

My humble opinion is that, unless he goes up a size or two in cable,
he will be storing up a whole load of voltage drop problems for the
future, which won't be an issue if it's EON's cable. Plus if he ever
falls out with the farmers who own the fields, he might end up with
some serious way-leave problems. EON etc. have powers to enforce way-
leaves in certain situations I believe.

Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.

Is this in France?

In the UK, isn't the wiring up to the meter the leccy company's problem
anyway, ie DIY that part isn't an option?

My friend is in the UK. The plan is to have the meter about 350m away
from the house. EON will connect to the newly constructed meter
enclosure, which will be close to their new transformer, and he will
connect from there to his house, thus assuming all responsibility for
the cable, the way-leave and the voltage-drop.

LGF

legrandfromage wrote:
On Jul 19, 1:29 pm, Clive George wrote:
On 19/07/2011 13:10, legrandfromage wrote:



Hi

A surprising one this - but what size cable would you use to connect a
house?

It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.

I'm trying to convince my friend that he'd be far better off letting
EON connect him to their new transformer (over 350m away across
fields), rather than do it himself. I'm slightly concerned that the
electrician who has quoted 50mm2 4-core, plus 35mm2 G/Y earth, might
be out of his depth too! It's a hell of a lot of cable to pull through
350m of (already laid) conduit!

My humble opinion is that, unless he goes up a size or two in cable,
he will be storing up a whole load of voltage drop problems for the
future, which won't be an issue if it's EON's cable. Plus if he ever
falls out with the farmers who own the fields, he might end up with
some serious way-leave problems. EON etc. have powers to enforce way-
leaves in certain situations I believe.

Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.

Is this in France?

In the UK, isn't the wiring up to the meter the leccy company's problem
anyway, ie DIY that part isn't an option?

My friend is in the UK. The plan is to have the meter about 350m away
from the house. EON will connect to the newly constructed meter
enclosure, which will be close to their new transformer, and he will
connect from there to his house, thus assuming all responsibility for
the cable, the way-leave and the voltage-drop.


http://www.tlc-direct.co.uk/Technica...ltageDrop.html

But only goes up to 16mm cable. In Italy I had to run cable 130 metres to
the nearest distribution pole. I used 16mm^2 which gives a 7V drop. Beyond
that I wouldn't like to guess what to use.

On Jul 19, 2:52*pm, Owain wrote:
On Jul 19, 1:42*pm, legrandfromage *wrote:

In the UK, isn't the wiring up to the meter the leccy company's problem
anyway, ie DIY that part isn't an option?

Not on new connections; the work is divided into what the leccy
company must do and what can be done competitively to leccy company
standards

My friend is in the UK. The plan is to have the meter about 350m away
from the house. EON will connect to the newly constructed meter
enclosure, which will be close to their new transformer, and he will
connect from there to his house, thus assuming all responsibility for
the cable, the way-leave and the voltage-drop.

Is the meter enclosure on EON's or the friend's land, or on someone
else's land? There may be security risks from tampering with supply or
theft of electricity on the load side of the meter.

I don't think you'll be able to export a PME earth 350 metres from the
meter to the house, so it would be better if the cable to the house
can be supplier's work and the supplier provide a PME at the house.

Owain

I was wondering about the earthing arrangements, and couldn't quite
understand why the electrician wasn't going to TT the whole thing.
RCBOs have been specified for most circuits as far as I can work out.
The meter enclosure will be in a hedge, at the foot of the pole with
the transformer on it. Tampering could be an issue - wouldn't it be
hilarious to turn it off!!!

I think EON quoted about £30K for the new transformer and connection
to the house - seems good value to me!

LGF

On Jul 19, 1:10*pm, legrandfromage wrote:
Hi

A surprising one this - but what size cable would you use to connect a
house?

It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.

How long is a piece of string? You need more detail than that to
assess the likely (and future) loading

I'm trying to convince my friend that he'd be far better off letting
EON connect him to their new transformer (over 350m away across
fields), rather than do it himself. I'm slightly concerned that the
electrician who has quoted 50mm2 4-core, plus 35mm2 G/Y earth, might
be out of his depth too! It's a hell of a lot of cable to pull through
350m of (already laid) conduit!

SNIP

It will probably pull out a lot easier when attached to the back of a
cable thieves lorry!

legrandfromage wrote:
Hi

A surprising one this - but what size cable would you use to connect a
house?

It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.

I'm trying to convince my friend that he'd be far better off letting
EON connect him to their new transformer (over 350m away across
fields), rather than do it himself. I'm slightly concerned that the
electrician who has quoted 50mm2 4-core, plus 35mm2 G/Y earth, might
be out of his depth too! It's a hell of a lot of cable to pull through
350m of (already laid) conduit!

My humble opinion is that, unless he goes up a size or two in cable,
he will be storing up a whole load of voltage drop problems for the
future, which won't be an issue if it's EON's cable. Plus if he ever
falls out with the farmers who own the fields, he might end up with
some serious way-leave problems. EON etc. have powers to enforce way-
leaves in certain situations I believe.

Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.

LGF
The voltage drop is less relevant in mains wiring than the power loss
- heating effect.

nevertheless I would install 100A cable simply because its so little
more you might as well.

And gives you enough to run a heat pump as well...

No reason not to run it yourself either, and simply leave the hookup to
the power company.

Clive George wrote:
On 19/07/2011 13:10, legrandfromage wrote:
Hi

A surprising one this - but what size cable would you use to connect a
house?

It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.

I'm trying to convince my friend that he'd be far better off letting
EON connect him to their new transformer (over 350m away across
fields), rather than do it himself. I'm slightly concerned that the
electrician who has quoted 50mm2 4-core, plus 35mm2 G/Y earth, might
be out of his depth too! It's a hell of a lot of cable to pull through
350m of (already laid) conduit!

My humble opinion is that, unless he goes up a size or two in cable,
he will be storing up a whole load of voltage drop problems for the
future, which won't be an issue if it's EON's cable. Plus if he ever
falls out with the farmers who own the fields, he might end up with
some serious way-leave problems. EON etc. have powers to enforce way-
leaves in certain situations I believe.

Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.

Is this in France?

In the UK, isn't the wiring up to the meter the leccy company's problem
anyway, ie DIY that part isn't an option?

I installed mine. A lot cheaper than the leccy co doing it. They gave me
the cable and a safety tape.

legrandfromage wrote:
On Jul 19, 1:29 pm, Clive George wrote:
On 19/07/2011 13:10, legrandfromage wrote:



Hi
A surprising one this - but what size cable would you use to connect a
house?
It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.
I'm trying to convince my friend that he'd be far better off letting
EON connect him to their new transformer (over 350m away across
fields), rather than do it himself. I'm slightly concerned that the
electrician who has quoted 50mm2 4-core, plus 35mm2 G/Y earth, might
be out of his depth too! It's a hell of a lot of cable to pull through
350m of (already laid) conduit!
My humble opinion is that, unless he goes up a size or two in cable,
he will be storing up a whole load of voltage drop problems for the
future, which won't be an issue if it's EON's cable. Plus if he ever
falls out with the farmers who own the fields, he might end up with
some serious way-leave problems. EON etc. have powers to enforce way-
leaves in certain situations I believe.
Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.
Is this in France?

In the UK, isn't the wiring up to the meter the leccy company's problem
anyway, ie DIY that part isn't an option?

My friend is in the UK. The plan is to have the meter about 350m away
from the house. EON will connect to the newly constructed meter
enclosure, which will be close to their new transformer, and he will
connect from there to his house, thus assuming all responsibility for
the cable, the way-leave and the voltage-drop.


Odd way to do it, but it works for me..


LGF

On Jul 19, 4:02*pm, The Natural Philosopher
wrote:
legrandfromage wrote:
Hi

A surprising one this - but what size cable would you use to connect a
house?

It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.

I'm trying to convince my friend that he'd be far better off letting
EON connect him to their new transformer (over 350m away across
fields), rather than do it himself. I'm slightly concerned that the
electrician who has quoted 50mm2 4-core, plus 35mm2 G/Y earth, might
be out of his depth too! It's a hell of a lot of cable to pull through
350m of (already laid) conduit!

My humble opinion is that, unless he goes up a size or two in cable,
he will be storing up a whole load of voltage drop problems for the
future, which won't be an issue if it's EON's cable. Plus if he ever
falls out with the farmers who own the fields, he might end up with
some serious way-leave problems. EON etc. have powers to enforce way-
leaves in certain situations I believe.

Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.

LGF

* The voltage drop is less relevant in mains wiring than the power loss
- heating effect.

nevertheless I would install 100A cable simply because its so little
more you might as well.

And gives you enough to run a heat pump as well...

No reason not to run it yourself either, and simply leave the hookup to
the power company.

As far as I'm aware you are permitted a small percentage voltage drop
from the origin of an installation (i.e. 350m away). So, for a
lighting circuit, this is supposed to be 3.5% max. I'm not sure how
easily that will be achieved given that the lighting circuit is going
to add ~50m.

What's 100A cable?

On 19/07/2011 13:10, legrandfromage wrote:
Hi

A surprising one this - but what size cable would you use to connect a
house?

It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.

I'm trying to convince my friend that he'd be far better off letting
EON connect him to their new transformer (over 350m away across
fields), rather than do it himself. I'm slightly concerned that the
electrician who has quoted 50mm2 4-core, plus 35mm2 G/Y earth, might
be out of his depth too! It's a hell of a lot of cable to pull through
350m of (already laid) conduit!

My humble opinion is that, unless he goes up a size or two in cable,
he will be storing up a whole load of voltage drop problems for the
future, which won't be an issue if it's EON's cable. Plus if he ever
falls out with the farmers who own the fields, he might end up with
some serious way-leave problems. EON etc. have powers to enforce way-
leaves in certain situations I believe.

Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.

LGF

Not an answer to your actual question, but a point regarding the pulling
of large cables.

At our work, where they had to pull at 240mm2 they pulled it in as 2
sets of 120mm2 singles, paralleled up.

They said the tended to use singles rather than a fat cable due to
manual handling and cable flexibility / termination considerations.

--
Ron

On 19/07/2011 13:42, legrandfromage wrote:
....
My friend is in the UK. The plan is to have the meter about 350m away
from the house. EON will connect to the newly constructed meter
enclosure, which will be close to their new transformer, and he will
connect from there to his house, thus assuming all responsibility for
the cable, the way-leave and the voltage-drop.

and for replacing it when someone nicks the lot.

Colin Bignell

legrandfromage wrote:
Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.

Ferret onna string, send ferret down pipe, attach progressivly
thicker string until strong enough to pull lube'd cables through.

JGH

On Tue, 19 Jul 2011 17:37:59 +0100, Nightjar wrote:

My friend is in the UK. The plan is to have the meter about 350m
away
from the house. EON will connect to the newly constructed meter
enclosure, which will be close to their new transformer, and he
will
connect from there to his house, thus assuming all responsibility
for
the cable, the way-leave and the voltage-drop.

and for replacing it when someone nicks the lot.

That I think is worth noting. I'd not want 350m of cable between the
meter and house. It'll have to be quite chuncky and therefore
enimently knickable. Not to mention the power loss, assume a 10v drop
that's 1/2 a unit for every 50A of load or 1/2 a unit for a 5A load
over 10 hours, the base load of a normal house with people in it is
around 5A.

Pretty sure the power companies are happy for others to dig trenches,
lay cables themselves and they just check that it's all been done
properly and connect up. As has been said they may even supply the
cable as it will be their responsibilty once connected.

--
Cheers
Dave.

In article 88ac63a9-3a86-45d9-a378-73e1c3ae0f21
@v37g2000yqm.googlegroups.com, says...

Hi

A surprising one this - but what size cable would you use to connect a
house?

It's a new, quite fancy, and quite big house. All electric - ground
source heat pump etc, and lots of potential for outbuildings, perhaps
even a swimming pool one day. It's got to be 3-phase, probably at
least 60A per phase.



I think it is a crazy idea to be running 350m at LV after the service
head. You will be responsible for the voltage drop and it will be
almost impossible to meet the regulations (3% lighting 5% power)
throughout the property without using oversize cables. If you want to
run the cable, fine, but let the DNO take it over and have the service
head and meter at the house end. As someone else has said otherwise you
will end up footing the bill for heating the ground around the cable.
If you ever install solar panels then you are meant to keep the voltage
drop(rise) to 1% which will be more difficult if the service head is
350m away.
Regards
Bruce

In article ,
Ron Lowe writes:

Not an answer to your actual question, but a point regarding the pulling
of large cables.

At our work, where they had to pull at 240mm2 they pulled it in as 2
sets of 120mm2 singles, paralleled up.

They said the tended to use singles rather than a fat cable due to
manual handling and cable flexibility / termination considerations.

Circuit protection for conductors in parallel is not simple.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Tue, 19 Jul 2011 21:06:47 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Ron Lowe writes:

Not an answer to your actual question, but a point regarding the pulling
of large cables.

At our work, where they had to pull at 240mm2 they pulled it in as 2
sets of 120mm2 singles, paralleled up.

They said the tended to use singles rather than a fat cable due to
manual handling and cable flexibility / termination considerations.

Circuit protection for conductors in parallel is not simple.

Why?


--

"The Other Mike" wrote in message
...
On Tue, 19 Jul 2011 21:06:47 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Ron Lowe writes:

Not an answer to your actual question, but a point regarding the pulling
of large cables.

At our work, where they had to pull at 240mm2 they pulled it in as 2
sets of 120mm2 singles, paralleled up.

They said the tended to use singles rather than a fat cable due to
manual handling and cable flexibility / termination considerations.

Circuit protection for conductors in parallel is not simple.

Why?

You can't guaranty the current flows equally down each conductor.
Its actually easy to fully protect them, just put a fuse in each conductor.
It just doesn't allow full use of the available copper.


--

In article ,
says...

Probably easier to come at this from the other way and work out the
maximum voltage drop per metre (Vdm) that we can tolerate. Lets argue
that the cable run is a distribution circuit (seems fair) and hence is
subject to a 5% drop limitation, so in this case 20V as this is a 400V
circuit. Lets assume 100A/phase.

But if you allow 5% voltage drop in that part of the installation, you
have already gone 2% beyond the total 3% voltage drop you are allowed
for the house lighting circuits. Voltage drop is measured from the
origin.
Regards
Bruce

jgharston writes:

legrandfromage wrote:
Any opinions on the cable size will be greatly appreciated, as will
any pointers on the best way to pull 350m of extremely heavy cable
through a conduit.

Ferret onna string, send ferret down pipe, attach progressivly
thicker string until strong enough to pull lube'd cables through.

By the end of this process, youll have one mighty strong ferret.

--
Jón Fairbairn
http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2010-09-14)

On Wed, 20 Jul 2011 18:21:12 +0100, "dennis@home"
wrote:



"The Other Mike" wrote in message
.. .
On Tue, 19 Jul 2011 21:06:47 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Ron Lowe writes:

Not an answer to your actual question, but a point regarding the pulling
of large cables.

At our work, where they had to pull at 240mm2 they pulled it in as 2
sets of 120mm2 singles, paralleled up.

They said the tended to use singles rather than a fat cable due to
manual handling and cable flexibility / termination considerations.

Circuit protection for conductors in parallel is not simple.

Why?

You can't guaranty the current flows equally down each conductor.
Its actually easy to fully protect them, just put a fuse in each conductor.
It just doesn't allow full use of the available copper.

Is that a guess or a fact?

It has zero impact on the thousands of miles of double and quad
conductor circuits on the HV grid system


--

The Other Mike wrote:
On Wed, 20 Jul 2011 18:21:12 +0100, "dennis@home"
wrote:



"The Other Mike" wrote in message
...
On Tue, 19 Jul 2011 21:06:47 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Ron Lowe writes:

Not an answer to your actual question, but a point regarding the
pulling of large cables.

At our work, where they had to pull at 240mm2 they pulled it in
as 2 sets of 120mm2 singles, paralleled up.

They said the tended to use singles rather than a fat cable due to
manual handling and cable flexibility / termination
considerations.

Circuit protection for conductors in parallel is not simple.

Why?

You can't guaranty the current flows equally down each conductor.
Its actually easy to fully protect them, just put a fuse in each
conductor. It just doesn't allow full use of the available copper.

Is that a guess or a fact?



He read it in the ladybird book of electrics.


--
Adam

"The Other Mike" wrote in message
...
On Wed, 20 Jul 2011 18:21:12 +0100, "dennis@home"
wrote:



"The Other Mike" wrote in message
. ..
On Tue, 19 Jul 2011 21:06:47 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Ron Lowe writes:

Not an answer to your actual question, but a point regarding the
pulling
of large cables.

At our work, where they had to pull at 240mm2 they pulled it in as 2
sets of 120mm2 singles, paralleled up.

They said the tended to use singles rather than a fat cable due to
manual handling and cable flexibility / termination considerations.

Circuit protection for conductors in parallel is not simple.

Why?

You can't guaranty the current flows equally down each conductor.
Its actually easy to fully protect them, just put a fuse in each
conductor.
It just doesn't allow full use of the available copper.

Is that a guess or a fact?

It has zero impact on the thousands of miles of double and quad
conductor circuits on the HV grid system

They are protected by constantly monitoring the load, temp, etc. of each
cable.
Actually each cable span between pylons, if you look you will see a sensor
next to each insulator.
It measures the angle of the cable, from which you can deduce the operating
conditions to see if its safe.

How to do that was a question that came up in my interview for the cegb
while I was doing my final year at uni.

On Thu, 21 Jul 2011 18:49:46 +0100, "dennis@home"
wrote:



"The Other Mike" wrote in message
.. .
On Wed, 20 Jul 2011 18:21:12 +0100, "dennis@home"
wrote:


You can't guaranty the current flows equally down each conductor.
Its actually easy to fully protect them, just put a fuse in each
conductor.
It just doesn't allow full use of the available copper.

Is that a guess or a fact?

It has zero impact on the thousands of miles of double and quad
conductor circuits on the HV grid system

They are protected by constantly monitoring the load

so far so good

temp, etc.

Fail

of each cable.

Not at all (although for underground cables there are CT's on each
'core')

Actually each cable span between pylons, if you look you will see a sensor
next to each insulator.

Now that is really funny.

Ever heard or arcing horns or stockbridge dampers? Evidently not.

Ever considered that the number of pylons with any sensors or with any
accesible communication infrastructure is a tiny fraction of the
total?

It measures the angle of the cable, from which you can deduce the operating
conditions to see if its safe.

Hilarious

How to do that was a question that came up in my interview for the cegb
while I was doing my final year at uni.

Thank **** you never made the grade otherwise the lights would have
gone out years ago.


--

The Other Mike wrote:
On Thu, 21 Jul 2011 18:49:46 +0100, "dennis@home"
wrote:



"The Other Mike" wrote in message
...
On Wed, 20 Jul 2011 18:21:12 +0100, "dennis@home"
wrote:


You can't guaranty the current flows equally down each conductor.
Its actually easy to fully protect them, just put a fuse in each
conductor.
It just doesn't allow full use of the available copper.

Is that a guess or a fact?

It has zero impact on the thousands of miles of double and quad
conductor circuits on the HV grid system

They are protected by constantly monitoring the load

so far so good

temp, etc.

Fail

of each cable.

Not at all (although for underground cables there are CT's on each
'core')

Actually each cable span between pylons, if you look you will see a
sensor next to each insulator.

Now that is really funny.

Ever heard or arcing horns or stockbridge dampers? Evidently not.

Ever considered that the number of pylons with any sensors or with any
accesible communication infrastructure is a tiny fraction of the
total?

It measures the angle of the cable, from which you can deduce the
operating conditions to see if its safe.

Hilarious

How to do that was a question that came up in my interview for the
cegb while I was doing my final year at uni.

Thank **** you never made the grade otherwise the lights would have
gone out years ago.

It's dennise, what else do you expect

"His eyes are open, the mouth moves, but Mr. Brain has long since departed"

--
Adam

"The Other Mike" wrote in message
...
On Thu, 21 Jul 2011 18:49:46 +0100, "dennis@home"
wrote:



"The Other Mike" wrote in message
. ..
On Wed, 20 Jul 2011 18:21:12 +0100, "dennis@home"
wrote:


You can't guaranty the current flows equally down each conductor.
Its actually easy to fully protect them, just put a fuse in each
conductor.
It just doesn't allow full use of the available copper.

Is that a guess or a fact?

It has zero impact on the thousands of miles of double and quad
conductor circuits on the HV grid system

They are protected by constantly monitoring the load

so far so good

temp, etc.

Fail

of each cable.

Not at all (although for underground cables there are CT's on each
'core')

So more than each cable then.


Actually each cable span between pylons, if you look you will see a sensor
next to each insulator.

Now that is really funny.

Ever heard or arcing horns

yes.

or stockbridge dampers?

No.

Evidently not.

Evidently wrong.


Ever considered that the number of pylons with any sensors or with any
accesible communication infrastructure is a tiny fraction of the
total?

It measures the angle of the cable, from which you can deduce the
operating
conditions to see if its safe.

Hilarious

So you are denying that it works then, you had better tell NG.


How to do that was a question that came up in my interview for the cegb
while I was doing my final year at uni.

Thank **** you never made the grade otherwise the lights would have
gone out years ago.

Maybe.

In article , dennis@home
scribeth thus


"The Other Mike" wrote in message
.. .
On Wed, 20 Jul 2011 18:21:12 +0100, "dennis@home"
wrote:



"The Other Mike" wrote in message
...
On Tue, 19 Jul 2011 21:06:47 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Ron Lowe writes:

Not an answer to your actual question, but a point regarding the
pulling
of large cables.

At our work, where they had to pull at 240mm2 they pulled it in as 2
sets of 120mm2 singles, paralleled up.

They said the tended to use singles rather than a fat cable due to
manual handling and cable flexibility / termination considerations.

Circuit protection for conductors in parallel is not simple.

Why?

You can't guaranty the current flows equally down each conductor.
Its actually easy to fully protect them, just put a fuse in each
conductor.
It just doesn't allow full use of the available copper.

Is that a guess or a fact?

It has zero impact on the thousands of miles of double and quad
conductor circuits on the HV grid system

They are protected by constantly monitoring the load, temp, etc. of each
cable.
Actually each cable span between pylons, if you look you will see a sensor
next to each insulator.
It measures the angle of the cable, from which you can deduce the operating
conditions to see if its safe.



How to do that was a question that came up in my interview for the cegb
while I was doing my final year at uni.


But did you get the job;?..
--
Tony Sayer

On Thu, 21 Jul 2011 22:13:07 +0100, "dennis@home"
wrote:



"The Other Mike" wrote in message
.. .
On Thu, 21 Jul 2011 18:49:46 +0100, "dennis@home"
wrote:



"The Other Mike" wrote in message
...
On Wed, 20 Jul 2011 18:21:12 +0100, "dennis@home"
wrote:


You can't guaranty the current flows equally down each conductor.
Its actually easy to fully protect them, just put a fuse in each
conductor.
It just doesn't allow full use of the available copper.

Is that a guess or a fact?

It has zero impact on the thousands of miles of double and quad
conductor circuits on the HV grid system

They are protected by constantly monitoring the load

so far so good

temp, etc.

Fail

of each cable.

Not at all (although for underground cables there are CT's on each
'core')

So more than each cable then.

No, just a VT and a CT on each phase at both ends for all two and four
conductor overhead lines everywhere on the 400kV and 275kV network.

The conductors are commoned as they come off the terminal tower before
they even meet any measuring or monitoring device.

The VT's and CT's, being bits of inert materials, have no knowledge of
the conductor construction. Restring an overhead line from four to
two conductor and the VT's and CT's don't need to change.

Actually each cable span between pylons, if you look you will see a sensor
next to each insulator.

Now that is really funny.

Ever heard or arcing horns

yes.

or stockbridge dampers?

No.

Then, by your own admission, you know sweet FAl about pylons and the
conductors strung from those insulators and the dangly bits situated
next to those insulators.

Evidently wrong.

You've failed again.

Ever considered that the number of pylons with any sensors or with any
accesible communication infrastructure is a tiny fraction of the
total?

It measures the angle of the cable, from which you can deduce the
operating
conditions to see if its safe.

Hilarious

So you are denying that it works then, you had better tell NG.

There is no need to deny anything. They aren't fitted.



--

On Jul 20, 6:55*pm, BruceB wrote:
In article ,
says...

Probably easier to come at this from the other way and work out the
maximum voltage drop per metre (Vdm) that we can tolerate. Lets argue
that the cable run is a distribution circuit (seems fair) and hence is
subject to a 5% drop limitation, so in this case 20V as this is a 400V
circuit. Lets assume 100A/phase.

But if you allow 5% voltage drop in that part of the installation, you
have already gone 2% beyond the total 3% voltage drop you are allowed
for the house lighting circuits. *Voltage drop is measured from the
origin.
Regards
Bruce

Out of curiosity only, is it permissible to add a tapchanger
transformer at the house to resolve excess Vdrop? I'm not suggesting
it as practical, just wondering what the 17th's position on it is.


NT

Is the OP using underground ducting for the cable or direct burial?
- Direct burial is cheapest, you need the trench clear of stones,
marking tape & depth suitable for the intended use of the ground.
- Cheap corrugated ducting soon adds up at 350m, makes replacement AND
theft of the cable easier, and may have considerable friction for
pulling if not a straight relatively level route. Manufacturers
specify limits on pull tension.
- Twinwall corrugated ducting is more expensive, has a perfectly
smooth bore, making pulling of cables somewhat easier.

TLC sell a lubricant which eases cable pulling.
Farmer offering to direct plough the cable with an attachment?

You can get lockable outdoor cabinets, more commonly used at sides of
roads, they can be heavy gauge steel or thickwall plastic. Whack on a
concrete base with suitable ducting, they use ground anchors to fix.
If the price is outrageous you might be able to weld one up (4mm steel
unless v-grooved needs a decent welder).

Apart from BS7671 requirements on voltage drop post meter, and DNO
ability to adjust tappings, if the meter is at the pole then you are
going to pay for power dissipation in a very long cable. That loss is
over only about 10-12 units a day at baseline load, but if you use E7
heating or E7 heatpumps the current draw and thus power lost becomes
more onerous. Cost out carefully.

In article ,
"dennis@home" writes:


"The Other Mike" wrote in message
...
On Tue, 19 Jul 2011 21:06:47 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Ron Lowe writes:

Not an answer to your actual question, but a point regarding the pulling
of large cables.

At our work, where they had to pull at 240mm2 they pulled it in as 2
sets of 120mm2 singles, paralleled up.

They said the tended to use singles rather than a fat cable due to
manual handling and cable flexibility / termination considerations.

Circuit protection for conductors in parallel is not simple.

Why?

You can't guaranty the current flows equally down each conductor.

Providing the conductors are all the same size and length (and hence
same resistance), and have good connections, and are long enough that
the conductor resistance is large relative to the connection
resistance, they will take equal currents.

The earlier versions of the 16th Ed wiring regs had a section
on conductors in parallel. (30/32A ring circuits are specifically
excluded, due to derating.)

Its actually easy to fully protect them, just put a fuse in each conductor.

That goes some way (but you have to use an interlocked breaker).
When you have more than two in parallel, you also have to allow
for backfeeding a fault from the far end. (So if I have 4 runs
in parallel protected at 100A each, and I short one of them to
ground, I can get 100A from the supply plus 300A backfed from
the far end down a single 100A cable, without tripping the
circuit protection.) For long runs, you also have to be careful
of meeting disconnect times when some of the runs are broken.

It just doesn't allow full use of the available copper.

?

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Jul 20, 6:55*pm, BruceB wrote:
In article ,
says...

Probably easier to come at this from the other way and work out the
maximum voltage drop per metre (Vdm) that we can tolerate. Lets argue
that the cable run is a distribution circuit (seems fair) and hence is
subject to a 5% drop limitation, so in this case 20V as this is a 400V
circuit. Lets assume 100A/phase.

But if you allow 5% voltage drop in that part of the installation, you
have already gone 2% beyond the total 3% voltage drop you are allowed
for the house lighting circuits. *Voltage drop is measured from the
origin.
Regards
Bruce

I spoke to the electrician. He has allowed 5% voltage drop from the
meter to the house. He claims this is a supply cable and does not
factor into final circuit v-d calculations.

He is also exporting the earth from the meter in 35mm green/yellow
wire. There will be a new transformer on a pole, so I'm guessing that
the supply company will put an earth spike or something in there.

So, given that the system will be earthed 350m away, is it possible
that the neutral and the earth in the house will be at a different
potential to the surrounding ground?

LGF

In article , Andrew Gabriel
scribeth thus
In article ,
"dennis@home" writes:


"The Other Mike" wrote in message
...
On Tue, 19 Jul 2011 21:06:47 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Ron Lowe writes:

Not an answer to your actual question, but a point regarding the pulling
of large cables.

At our work, where they had to pull at 240mm2 they pulled it in as 2
sets of 120mm2 singles, paralleled up.

They said the tended to use singles rather than a fat cable due to
manual handling and cable flexibility / termination considerations.

Circuit protection for conductors in parallel is not simple.

Why?

You can't guaranty the current flows equally down each conductor.

Providing the conductors are all the same size and length (and hence
same resistance), and have good connections, and are long enough that
the conductor resistance is large relative to the connection
resistance, they will take equal currents.

The earlier versions of the 16th Ed wiring regs had a section
on conductors in parallel. (30/32A ring circuits are specifically
excluded, due to derating.)

Its actually easy to fully protect them, just put a fuse in each conductor.

That goes some way (but you have to use an interlocked breaker).
When you have more than two in parallel, you also have to allow
for backfeeding a fault from the far end. (So if I have 4 runs
in parallel protected at 100A each, and I short one of them to
ground, I can get 100A from the supply plus 300A backfed from
the far end down a single 100A cable, without tripping the
circuit protection.) For long runs, you also have to be careful
of meeting disconnect times when some of the runs are broken.

It just doesn't allow full use of the available copper.

?


No need to "?" it, in Dennis's world there are his very own set of laws
Ohm's is outa the window;!..

--
Tony Sayer

In article 5f7f7936-f8a4-4c30-b1fb-a061bd876512
@m10g2000yqd.googlegroups.com, says...

I spoke to the electrician. He has allowed 5% voltage drop from the
meter to the house. He claims this is a supply cable and does not
factor into final circuit v-d calculations.

He is also exporting the earth from the meter in 35mm green/yellow
wire. There will be a new transformer on a pole, so I'm guessing that
the supply company will put an earth spike or something in there.

So, given that the system will be earthed 350m away, is it possible
that the neutral and the earth in the house will be at a different
potential to the surrounding ground?


Your electrician is wrong if that is what he said and the cable is part
of the consumer installation. If the cable is before the meter it is a
supply cable under DNO control and does not count in the voltage drop
calculations in a consumer's installation. If it is after the meter
then it does feature in the voltage drop calculations.

The reason is that that the DNO will make sure the voltage is within
spec at the supply terminals/meter, wherever that is. So if it is at
the low end of the acceptable range 350m from the house, then by the
time it reaches the house it could be under.

Relevant regulation is 525.101:
"The above requirements are deemed satisfied if the voltage drop between
the origin of the installation (usually the supply terminals) and a
socket outlet or the terminals of current-using equipment does not
exceed that stated in Appendix 4 section 6.4."
(The latter states the 3% and 5% requirements)

There is a get out for your electrician under 525.1 if he knows (for
example by measurement) the voltage will "be greater than the lower
limit corresponding to the product standard relevant to the
equipement." In that case he could allow more than the 3% and 5% drops.
But if in future it was ever lower than you wanted then the DNO would
have no interest in raising it for you provided it was within range at
the supply terminals.

On your latter point, yes it is possible the earth voltage will be
different over that distance. If it was a DNO PME supply then they
would probably bury an additional earth rod in the trench where the
mains cable joined the service cable just before it entered your house
or meter box. You are not allowed to have any connection betwen neutral
and earth within the installation as a consumer, but you could add a
connection to a local earth rod from say the consumer unit in the house.

My advice remains have the dno supply terminals in the house or as close
to the house as possible.

Regards
Bruce

"tony sayer" wrote in message
...

It just doesn't allow full use of the available copper.

?


No need to "?" it, in Dennis's world there are his very own set of laws
Ohm's is outa the window;!..

Its ohm's law that makes it that way.
Unless you have exactly the same resistance down the two cables you don't
get equal currents.
If you don't have equal currents you can't run the wires at their maximum so
the current capacity of parallel conductors is less than the nominal area
would allow.

Of course you could just add some known resistance in to balance them. 8-)

dennis@home wrote:
"tony sayer" wrote in message
...

It just doesn't allow full use of the available copper.

?


No need to "?" it, in Dennis's world there are his very own set of
laws Ohm's is outa the window;!..

Its ohm's law that makes it that way.

Unless you have exactly the same resistance down the two cables you
don't get equal currents.

Best not mention impedance then.

If you don't have equal currents you can't run the wires at their
maximum so the current capacity of parallel conductors is less than
the nominal area would allow.


You are Forrest Gump AIKMFP

Of course you could just add some known resistance in to balance
them.

Your skull has high resistance. Nothing enters your brain.

--
Adam

On Jul 23, 5:36*pm, BruceB wrote:
In article 5f7f7936-f8a4-4c30-b1fb-a061bd876512
@m10g2000yqd.googlegroups.com, says...



I spoke to the electrician. He has allowed 5% voltage drop from the
meter to the house. He claims this is a supply cable and does not
factor into final circuit v-d calculations.

He is also exporting the earth from the meter in 35mm green/yellow
wire. There will be a new transformer on a pole, so I'm guessing that
the supply company will put an earth spike or something in there.

So, given that the system will be earthed 350m away, is it possible
that the neutral and the earth in the house will be at a different
potential to the surrounding ground?

Your electrician is wrong if that is what he said and the cable is part
of the consumer installation. *If the cable is before the meter it is a
supply cable under DNO control and does not count in the voltage drop
calculations in a consumer's installation. *If it is after the meter
then it does feature in the voltage drop calculations.

The reason is that that the DNO will make sure the voltage is within
spec at the supply terminals/meter, wherever that is. *So if it is at
the low end of the acceptable range 350m from the house, then by the
time it reaches the house it could be under.

Relevant regulation is 525.101:
"The above requirements are deemed satisfied if the voltage drop between
the origin of the installation (usually the supply terminals) and a
socket outlet or the terminals of current-using equipment does not
exceed that stated in Appendix 4 section 6.4."
(The latter states the 3% and 5% requirements)

There is a get out for your electrician under 525.1 if he knows (for
example by measurement) the voltage will "be greater than the lower
limit corresponding to the product standard relevant to the
equipement." *In that case he could allow more than the 3% and 5% drops.. *
But if in future it was ever lower than you wanted then the DNO would
have no interest in raising it for you provided it was within range at
the supply terminals.

On your latter point, yes it is possible the earth voltage will be
different over that distance. *If it was a DNO PME supply then they
would probably bury an additional earth rod in the trench where the
mains cable joined the service cable just before it entered your house
or meter box. *You are not allowed to have any connection betwen neutral
and earth within the installation as a consumer, but you could add a
connection to a local earth rod from say the consumer unit in the house.

My advice remains have the dno supply terminals in the house or as close
to the house as possible.

Regards
Bruce

Let me make it abundantly clear that this is not my new fancy house or
my electrician. I'm simply a concerned friend. There is absolutely no
way I would consider this just to "save" £10k. I mean, each of their
solid basalt baths is going to cost that much! This house is in a
prominent beauty spot, mostly underground, and will be finished to a
very high standard. Skimping on the electricity supply is madness, but
then I suppose it would mean the kitchen won't have all those fancy
gadgets...

I completely agree with your advice, which is basically what I've been
trying to tell them. The NICEIC "Approved Contractor" is seeing pound
signs I think, and is out of his depth.

LGF

In article 77a10650-9932-47fb-87a9-23c43ff48579
@l18g2000yql.googlegroups.com, says...

Let me make it abundantly clear that this is not my new fancy house or
my electrician. I'm simply a concerned friend. There is absolutely no
way I would consider this just to "save" £10k.

acknowledged. my poor wording.

"ARWadsworth" wrote in message
...
dennis@home wrote:
"tony sayer" wrote in message
...

It just doesn't allow full use of the available copper.

?


No need to "?" it, in Dennis's world there are his very own set of
laws Ohm's is outa the window;!..

Its ohm's law that makes it that way.

Unless you have exactly the same resistance down the two cables you
don't get equal currents.

Best not mention impedance then.

Better not as you would have no chance of showing the impedance of two
pieces of copper cable had any significance.


If you don't have equal currents you can't run the wires at their
maximum so the current capacity of parallel conductors is less than
the nominal area would allow.


You are Forrest Gump AIKMFP

Of course you could just add some known resistance in to balance
them.

Your skull has high resistance. Nothing enters your brain.

Well at least I know the impedance is going to make naff all difference.

dennis@home wrote:
"ARWadsworth" wrote in message
...
dennis@home wrote:
"tony sayer" wrote in message
...

It just doesn't allow full use of the available copper.

?


No need to "?" it, in Dennis's world there are his very own set of
laws Ohm's is outa the window;!..

Its ohm's law that makes it that way.

Unless you have exactly the same resistance down the two cables you
don't get equal currents.

Best not mention impedance then.

Better not as you would have no chance of showing the impedance of two
pieces of copper cable had any significance.


If you don't have equal currents you can't run the wires at their
maximum so the current capacity of parallel conductors is less than
the nominal area would allow.


You are Forrest Gump AIKMFP

Of course you could just add some known resistance in to balance
them.

Your skull has high resistance. Nothing enters your brain.

Well at least I know the impedance is going to make naff all
difference.

I'll add electrics to the list of things in which you are an incompetent
****.

--
Adam