Is there any reason not to have an earth rod indoors?
TT system.

I've got 2 earth rods outdoors,
can I keep them and add a third indoors so there's less resistance?


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

[george]

On Mon, 25 Dec 2017 04:20:13 -0800, George Miles wrote:

Is there any reason not to have an earth rod indoors?
TT system.

I've got 2 earth rods outdoors,
can I keep them and add a third indoors so there's less resistance?

What is your earth rod resistance now?
Adding an extra rod is not guaranteed to lower the total resistance.
If you are currently getting 10 ohms than adding another rod will not
really help, however if you have 150ohms or so, then an extra, or deeper
rod may well help.

On Mon, 25 Dec 2017 07:22:36 -0600, Alan wrote:

What is your earth rod resistance now?
Adding an extra rod is not guaranteed to lower the total resistance.
If you are currently getting 10 ohms than adding another rod will not
really help, however if you have 150ohms or so, then an extra, or deeper
rod may well help.

Should really be earth loop *impedance* tested at 50Hz.



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protocols constitutes acceptance of this condition.

On 25/12/2017 12:20, George Miles wrote:
Is there any reason not to have an earth rod indoors?
TT system.

I've got 2 earth rods outdoors,
can I keep them and add a third indoors so there's less resistance?

Do you live in a mud hut with an earth floor?

--
Max Demian

The Earth Impedance has been tested and is OK,
but the plastic casing covering the earth wires clipped to the wall has been broken,
it's where it can get knocked by wheelbarrows etc,
it would be so much neater to not have wires clipped to outside walls
but to have the earth rod under the consumer unit indoors.

The floor is flagstones on earth,
(its a Victorian house)
so I should be able to put an earth rod indoors
even if it means drilling through some footing
i hope

[George]

On Monday, December 25, 2017 at 12:20:16 PM UTC, George Miles wrote:
Is there any reason not to have an earth rod indoors?
TT system.

I've got 2 earth rods outdoors,
can I keep them and add a third indoors so there's less resistance?


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

[george]

On 25/12/2017 12:20, George Miles wrote:
Is there any reason not to have an earth rod indoors?
TT system.

I've got 2 earth rods outdoors,
can I keep them and add a third indoors so there's less resistance?

No reason why not, although you may find it harder to get a low
impedance in what will likely be drier soil.

--
Cheers,

John.

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On 25/12/2017 15:09, John Rumm wrote:
On 25/12/2017 12:20, George Miles wrote:
Is there any reason not to have an earth rod indoors?
TT system.

I've got 2 earth rods outdoors,
can I keep them and add a third indoors so there's less resistance?

No reason why not, although you may find it harder to get a low
impedance in what will likely be drier soil.


So, not a problem for those with 'internal wells' that are now
'features'.

On 25/12/2017 16:43, Andrew wrote:
On 25/12/2017 15:09, John Rumm wrote:
On 25/12/2017 12:20, George Miles wrote:
Is there any reason not to have an earth rod indoors?
TT system.

I've got 2 earth rods outdoors,
can I keep them and add a third indoors so there's less resistance?

No reason why not, although you may find it harder to get a low
impedance in what will likely be drier soil.


So, not a problem for those with 'internal wells' that are now
'features'.

I feel I have missed something?

--
Cheers,

John.

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On 25/12/2017 18:18, John Rumm wrote:

I feel I have missed something?

Access for inspection and testing? You might not want an earth pit[*]
visible FVSO "indoors".
[*] e.g.https://www.screwfix.com/p/plastic-i...-pit/59527#_=p

--
Andy

On 25/12/2017 22:08, Andy Wade wrote:
On 25/12/2017 18:18, John Rumm wrote:

I feel I have missed something?

Access for inspection and testing? You might not want an earth pit[*]
visible FVSO "indoors".

[*] e.g.https://www.screwfix.com/p/plastic-i...-pit/59527#_=p

ISTM if you have a slab floor, having one you can lift for access to
your inspection pit[1] would not be unreasonable.

[1] or more typical terminal cover:

https://www.tlc-direct.co.uk/Products/MTETC.html


--
Cheers,

John.

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|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

replying to George Miles, Iggy wrote:
Yes, you bring unregulated and unwanted electricity into the building and you
may SEVERELY worsen your earthing. Close lightning strikes energize the earth
and would energize your earth rod. Poor earthing conditions are dry soil, so
being under the building's footprint could mean little to no earthing actually
happens. The 3rd rod should NOT be a replacement of the existing 2 and MUST
only be added to the existing 2 by a jumper conductor...ONLY IF determined to
be needed or beneficial.

This addition or by driving your existing rods deeper, is the ONLY way to
reduce your resistance. But, what is your current resistance? If you're
already at very low resistance, then you likely can't make it any better
because you're down to the conductor's own resistance. Don't do anything
unless and until you know what your resistance is. More rods IS NOT better and
WILL only extend your reach to pick up static electricity, fallen power-line
or lightning energy...a deeper single rod is factually best.

--
for full context, visit https://www.homeownershub.com/uk-diy...s-1258572-.htm

Citation please

Also of course when dealing with such low impedance systems the way you
connect them together will matter as well. some very thick copper?
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Alan" wrote in message
...
On Mon, 25 Dec 2017 04:20:13 -0800, George Miles wrote:

Is there any reason not to have an earth rod indoors?
TT system.

I've got 2 earth rods outdoors,
can I keep them and add a third indoors so there's less resistance?

What is your earth rod resistance now?
Adding an extra rod is not guaranteed to lower the total resistance.
If you are currently getting 10 ohms than adding another rod will not
really help, however if you have 150ohms or so, then an extra, or deeper
rod may well help.

On 26/12/17 08:24, Cynic wrote:
Citation please

https://www.citation.co.uk/


--
All political activity makes complete sense once the proposition that
all government is basically a self-legalising protection racket, is
fully understood.

Brian Gaff wrote:

Also of course when dealing with such low impedance systems the way you
connect them together will matter as well. some very thick copper?
Brian

I don't think domestic earth systems are as low impedance as one might
think. Someone said between 10ohms and 150ohms, and these are the sort
of figures attainable without burying huge amounts of copper. Conductor
diameter is more governed by possible fault currents than anything else.
Also mechanical strength may be relevant if exposed. You won't go far
wrong in a house using 16mm^2 and that may be unnecessarily big.

There are, of course, regulations you can look up if necessary. But
huge bus bars are probably not useful.

--

Roger Hayter

Andy Wade wrote:

On 25/12/2017 18:18, John Rumm wrote:

I feel I have missed something?

Access for inspection and testing? You might not want an earth pit[*]
visible FVSO "indoors".

[*] e.g.https://www.screwfix.com/p/plastic-i...-pit/59527#_=p

I was momentarily surprised that your URL gave the stock position at my
local Screwfix; until I remembered the miracle of cookies.

--

Roger Hayter

On 26/12/2017 05:14, Iggy wrote:
replying to George Miles, Iggy wrote:
Yes, you bring unregulated and unwanted electricity into the building
and you may SEVERELY worsen your earthing.

That seems unlikely. You may make little or no improvement, but so long
as you are not disconnecting the existing electrode its not going to get
worse.

Close lightning strikes energize the
earth
and would energize your earth rod. Poor earthing conditions are dry
soil, so
being under the building's footprint could mean little to no earthing
actually
happens.

That really depends on the local soil conditions.

The 3rd rod should NOT be a replacement of the existing 2 and MUST
only be added to the existing 2 by a jumper conductor...ONLY IF
determined to
be needed or beneficial.

The benefit it sounds like the OP is aiming for is that of better
redundancy and fault tolerance, since the connection to the existing
electrode is vulnerable to damage.

(Protecting the existing main connection better would seem prudent also)

This addition or by driving your existing rods deeper, is the ONLY way to
reduce your resistance. But, what is your current resistance? If you're

Multiple rods are ok (and are commonly used in the supply side of PME
installations for example), but ideally don't want to be too close
together such that they are in overlapping resistance areas.

already at very low resistance, then you likely can't make it any better
because you're down to the conductor's own resistance. Don't do anything
unless and until you know what your resistance is. More rods IS NOT
better and

You can't say that with any certainty. More rods "may" not be better -
but then again they might. It will depend on the circumstances and local
soil conditions.

WILL only extend your reach to pick up static electricity, fallen
power-line
or lightning energy...a deeper single rod is factually best.

I suspect if you have a lightening strike or fallen power line *inside*
your property, you have other things to worry about.


--
Cheers,

John.

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On Tuesday, 26 December 2017 05:14:04 UTC, Iggy wrote:
replying to George Miles, Iggy wrote:
Yes, you bring unregulated and unwanted electricity into the building and you
may SEVERELY worsen your earthing. Close lightning strikes energize the earth
and would energize your earth rod. Poor earthing conditions are dry soil, so
being under the building's footprint could mean little to no earthing actually
happens. The 3rd rod should NOT be a replacement of the existing 2 and MUST
only be added to the existing 2 by a jumper conductor...ONLY IF determined to
be needed or beneficial.

This addition or by driving your existing rods deeper, is the ONLY way to
reduce your resistance. But, what is your current resistance? If you're
already at very low resistance, then you likely can't make it any better
because you're down to the conductor's own resistance. Don't do anything
unless and until you know what your resistance is. More rods IS NOT better and
WILL only extend your reach to pick up static electricity, fallen power-line
or lightning energy...a deeper single rod is factually best.

You sure do talk cobblers

On 25/12/2017 22:08, Andy Wade wrote:
On 25/12/2017 18:18, John Rumm wrote:

I feel I have missed something?

Access for inspection and testing?Â* You might not want an earth pit[*]
visible FVSO "indoors".

[*] e.g.https://www.screwfix.com/p/plastic-i...-pit/59527#_=p


Well I was thinking of those programs like Homes Under the hammer, which
was one situation where a house bought at auction turned out to have
an old well inside the property.

It was dry-ish but with some nice ferns growing so the new owners
installed some wall-washer lights and put an inch thick slab of
glass over it as part of their new kitchen floor. It looked quite
interesting, but I would have thought at a wine store would
have been a better use for it.

Being not-dry, I presume they could have stuck their TT earth
rod down there at the bottom ?.

Whats wrong with ' overlapping resistance areas ' ?

John Rumm wrote:
"Multiple rods are ok (and are commonly used in the supply side of PME
installations for example), but ideally don't want to be too close
together such that they are in overlapping resistance areas. "

The existing earth rods are about a yard outside the backdoor,
the proposed indoors one would be just inside the back door under the consumer units.

The existing TT earth inductance was measured a new weeks ago and was OK,
but I dont have the figures here.

[geoorge]

On Tue, 26 Dec 2017 14:06:01 +0000, Andrew
wrote:

On 25/12/2017 22:08, Andy Wade wrote:
On 25/12/2017 18:18, John Rumm wrote:

I feel I have missed something?

Access for inspection and testing?Â* You might not want an earth pit[*]
visible FVSO "indoors".

[*]
e.g.https://www.screwfix.com/p/plastic-i...-pit/59527#_=p


Well I was thinking of those programs like Homes Under the hammer, which
was one situation where a house bought at auction turned out to have an
old well inside the property.

It was dry-ish but with some nice ferns growing so the new owners
installed some wall-washer lights and put an inch thick slab of glass
over it as part of their new kitchen floor. It looked quite interesting,
but I would have thought at a wine store would have been a better use
for it.

Being not-dry, I presume they could have stuck their TT earth rod down
there at the bottom ?.


Ooh!

A nice earth (RF)

Avpx


--
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(Sourcery)
15:45:01 up 2 days, 6:08, 5 users, load average: 0.67, 0.55, 0.51

replying to John Rumm, Iggy wrote:
1 - Seems unlikely? What if there's a plumbing leak, rain flooding into the
basement or an overflowing washer? Thanks but no thanks for that "fun" in a
lightning storm.

2 - Yep, that's why I said "could".

3 - Of course, I don't disagree with better protection, but there's absolutely
no such thing as redundancy. A 2nd rod and connection would send power into 1
earth, through the entire building's appliances and out the other earth...you
just fried every device and person in contact with any device.

4 - Again, the more rods and distance just becomes further reach and obtaining
what was missed before. You unwittingly turn the system into a lightning
arrestor and melt the incapable earthing entirely.

5 - I just demonstrated the more rods failure. But how is saying, find out
what you have before doing any such nonsense, nonsense? He very well could be
extremely low already and doesn't know it. Earthing of only a certain
resistance range is needed, anything more kills its operation and anything
less changes nor improves nothing...he, uncommonly, has 2 for a reason.

6 - Sorry but, that's absolutely wrong. A rather large area (bigger than the
whole house) will be energized by lightning or even a power-line. Why do you
think they say to stay off corded telephones, earthed appliances and that's
including computers during lightning storms? Not new stuff.

7 - I appreciate your points, but you desperately need an Earthing Refresher.
You have some very bad information. Thus why, PME's are banned for broad area
situations.

--
for full context, visit https://www.homeownershub.com/uk-diy...s-1258572-.htm

On Tuesday, 26 December 2017 16:44:06 UTC, Iggy wrote:
replying to John Rumm, Iggy wrote:
1 - Seems unlikely? What if there's a plumbing leak, rain flooding into the
basement or an overflowing washer? Thanks but no thanks for that "fun" in a
lightning storm.

2 - Yep, that's why I said "could".

3 - Of course, I don't disagree with better protection, but there's absolutely
no such thing as redundancy. A 2nd rod and connection would send power into 1
earth, through the entire building's appliances and out the other earth...you
just fried every device and person in contact with any device.

4 - Again, the more rods and distance just becomes further reach and obtaining
what was missed before. You unwittingly turn the system into a lightning
arrestor and melt the incapable earthing entirely.

5 - I just demonstrated the more rods failure. But how is saying, find out
what you have before doing any such nonsense, nonsense? He very well could be
extremely low already and doesn't know it. Earthing of only a certain
resistance range is needed, anything more kills its operation and anything
less changes nor improves nothing...he, uncommonly, has 2 for a reason.

6 - Sorry but, that's absolutely wrong. A rather large area (bigger than the
whole house) will be energized by lightning or even a power-line. Why do you
think they say to stay off corded telephones, earthed appliances and that's
including computers during lightning storms? Not new stuff.

7 - I appreciate your points, but you desperately need an Earthing Refresher.
You have some very bad information. Thus why, PME's are banned for broad area
situations.

It helps to quote what you're replying to, otherwise you make even less sense.

I dont know why Iggy is talking about Lightening:
My On Site Guide says the earthing conductor need only be 2.5 mm-squared for TT if protected, I think that'd melt with lightening.

But 2.5 mm-squared does seem very thin compared to the new meter tails to the consumer units and earth wires i was sold with them. I dont understand why OSG Table 4.4.ii says only 2.5 mm-squared

I thought the earthing conductor is for use in case of an electrical fault, a loose live wire, earthing most of the current through copper not through me until a fuse blows or RCB trips.

There's an 80 or 100 amp main fuse isnt there,
which would be of no use for lightening.
Or would it?

[george]

On 26/12/2017 16:44, Iggy wrote:

replying to George Miles, Iggy wrote:
Yes, you bring unregulated and unwanted electricity into the building
and you may SEVERELY worsen your earthing.

replying to John Rumm, Iggy wrote:
1 - Seems unlikely? What if there's a plumbing leak,

Woa there horse, you are romping off at at a tangent...

You said "you bring unregulated and unwanted electricity into the building"

I was pointing out this was nonsense. If you give it a moments thought
you would realise that all the metalwork of any class 1 appliances in
the building, plus the other main metallic services, and any extraneous
conductive paths around the inside of the property are *already"
connected to the earth spike outside. Having an additional one inside
does not in any material way change this.

You also said "and you may SEVERELY worsen your earthing" which I what I
was highlighted was unlikely.

rain flooding into the
basement or an overflowing washer? Thanks but no thanks for that "fun" in a
lightning storm.

2 - Yep, that's why I said "could".

3 - Of course, I don't disagree with better protection, but there's
absolutely no such thing as redundancy. A 2nd rod and connection would send power
into 1 earth, through the entire building's appliances and out the other
earth...you just fried every device and person in contact with any device.

Again, that really makes no sense.

How is having an earth rod connection inside the property any different
from having a main equipotential bond to metallic gas and water mains,
which are also long lengths of copper "rod" driven into the soil within
the perimeter of the property?

4 - Again, the more rods and distance just becomes further reach and
obtaining what was missed before. You unwittingly turn the system into a lightning
arrestor and melt the incapable earthing entirely.

So the OP has two external electrodes, plus let's say two de-facto
internal ones[1] already (assuming he has gas/water mains supplies). You
are suggesting that one additional electrode is going to fundamentally
change either the likelihood or the deleterious effects on the property
of a lightening strike?

[1] Note that while one may not rely on the fortuitous earthing effect
provided by main equipotential bonds to achieve adequate earthing, the
effects can't be ignored for the purposes of this discussion.

5 - I just demonstrated the more rods failure.

I don't believe you did.

BS7671 17th edition section 542.2 does not preclude multiple earth
electrodes.

If you refer to BS 7430:2011 (Code of practice for earthing electrical
installation), section 9.5.3 "Rod electrode" it notes:

"A number of rods may be connected in parallel and the resistance is
approximately reciprocal to the number of rods employed, so long as the
separation is outside of the resistance area of the each rod."

But how is saying, find out
what you have before doing any such nonsense, nonsense?

I did not say that.

He very well
could be extremely low already and doesn't know it. Earthing of only a certain
resistance range is needed, anything more kills its operation and anything
less changes nor improves nothing...he, uncommonly, has 2 for a reason.

Perhaps to achieve a usable impedance all year round.

6 - Sorry but, that's absolutely wrong. A rather large area (bigger than
the whole house) will be energized by lightning or even a power-line. Why do
you think they say to stay off corded telephones, earthed appliances and that's
including computers during lightning storms? Not new stuff.

What exactly are claiming is "wrong"?

You are no doubt aware that bonding connections between a lightening
protection system (when installed) are also required[2] to be made to
the buildings protective earthing system?

[2] See BS EN 62305-1:2006 Protection against lightening general principles

7 - I appreciate your points, but you desperately need an Earthing
Refresher.

Perhaps I am not the only one.

You have some very bad information. Thus why, PME's are banned for broad
area situations.

There is a requirement with PME to extend the equipotential zone to all
parts of the installation where you also export the PME earth. That can
make its use impractical, but that is not a "ban" as such. Do you have a
citation?


--
Cheers,

John.

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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 26/12/2017 15:48, George Miles wrote:

Whats wrong with ' overlapping resistance areas ' ?

Within a single installation, it just means that the rods don't behave
as fully independent connections to earth - so its better to test them
as a single system rather than in isolation.

Its more problematic when different dwellings have supposedly
independent connections to earth but they are via electrodes with an
overlapping resistance area. Then a fault current flowing to earth from
one property can induce a voltage to be present on the other properties
earthing system.

John Rumm wrote:
"Multiple rods are ok (and are commonly used in the supply side of PME
installations for example), but ideally don't want to be too close
together such that they are in overlapping resistance areas. "

The existing earth rods are about a yard outside the backdoor,
the proposed indoors one would be just inside the back door under the consumer units.

The existing TT earth inductance was measured a new weeks ago and was OK,
but I dont have the figures here.

[geoorge]



--
Cheers,

John.

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

On 26/12/2017 18:05, George Miles wrote:

I dont know why Iggy is talking about Lightening: My On Site Guide
says the earthing conductor need only be 2.5 mm-squared for TT if
protected, I think that'd melt with lightening.

But 2.5 mm-squared does seem very thin compared to the new meter
tails to the consumer units and earth wires i was sold with them. I
dont understand why OSG Table 4.4.ii says only 2.5 mm-squared

Because with a TT system its assumed that the external earth impedance
will exceed 1 ohm, and in most practical situations will be at best
several times that.

(if your TT earth impedance is less than 1 ohm, then the same rules as
as for TN systems should be used instead)

So in practice you maximum prospective fault current would be limited to
230A.

Well within the fault withstand capability of a 2.5mm^2 CSA conductor
with the maximum allowed disconnection time of 1 second for a TT system.

You can do an adiabatic check to be su

if you take the minimum required conductor size S as:

S = sqrt( I^2 x t ) / k

(and k = 115 for PVC insulated wire)

So S = ( 230^2 x 1 ) / 115 = 2mm

(and in reality even a time delayed RCD will operate more quickly than 1
sec)

I thought the earthing conductor is for use in case of an electrical
fault, a loose live wire, earthing most of the current through copper
not through me until a fuse blows or RCB trips.

Generally TT systems will rely on RCDs to clear faults to earth since in
may cases there may be inadequate prospective fault current to operate a
fuse or MCB.

There's an 80 or 100 amp main fuse isnt there, which would be of no
use for lightening. Or would it?

No. If its just forced a conductive path through 100's or 1000's of
metres of air, an extra few mm of fuse is not going to help!



--
Cheers,

John.

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

On Tue, 26 Dec 2017 10:05:56 -0800, George Miles wrote:

I dont know why Iggy is talking about Lightening:
My On Site Guide says the earthing conductor need only be 2.5 mm-squared
for TT if protected, I think that'd melt with lightening.

Most probably.

But 2.5 mm-squared does seem very thin compared to the new meter tails
to the consumer units and earth wires i was sold with them. I dont
understand why OSG Table 4.4.ii says only 2.5 mm-squared

It's all to do with the fault current the earthing conductor will be
carrying under fault conditions, i.e. a Line to earth fault. As the Earth
Fault Loop Impedance will be pretty high (20 ohms+?), it will only be
required to carry a low fault current, and can withstand that current
long enough to allow the RCD to trip.

I thought the earthing conductor is for use in case of an electrical
fault, a loose live wire, earthing most of the current through copper
not through me until a fuse blows or RCB trips.

Yes, that's right.

There's an 80 or 100 amp main fuse isnt there,
which would be of no use for lightening.
Or would it?

No, it'd be no good, as it would blow fast enough to stop any lightening
surge current damaging any equipment in your house. However, the odds of
that happening are so remote, that we mostly dont even consider it a risk
in a typical house. A large house on top of a hill, then maybe.

The 80 or 100 amp fuse will also be pretty useless for you if you touch
live and earth at the same time, as it'd never blow. In a typical TT
installation, a 32Amp circuit breaker is also unlikely to trip when you
touch L + E simultaneously.
That's because your Earth Fault Loop Impedance will be so high that there
will not be enough fault current to trip the circuit breaker. A 32A CB
will trip instantaneously (~0.1 second) with ~160A flowing through it.
Your total fault current with a 20 ohm EFLI (your earth rod resistance)
will be about 80 Amps, so you'll be holding that L+E for quite a while
before the circuit breaker trips. You'll be holding it forever for the
main fuse to blow.
This is why RCD protection is needed for TT installations. The RCD will
trip in less then 300mS, probably faster for a 30mA RCD.
Your current rod EFLI will be less than 200ohms, possibly as low as 10
ohms, but, IME, usually in the range of 30-50 ohms. Adding more rods, and
deeper rods will bring it down, but there is a limit, especially in rocky
areas, where it just is not possible to get a lower EFLI.

O
No, it'd be no good, as it would blow fast enough to stop any lightening


WOULDNT
Doh.

Alan wrote:

O
No, it'd be no good, as it would blow fast enough to stop any lightening


WOULDNT
Doh.

Since we're doing corrections, can we correct 'lightning' without an e
please?

--

Roger Hayter

On 26/12/2017 16:44, Iggy wrote:

7 - I appreciate your points, but you desperately need an Earthing
Refresher.
You have some very bad information. Thus why, PME's are banned for broad
area
situations.



Care to define a "broad area situation".



--
Adam

On Tue, 26 Dec 2017 10:05:56 -0800 (PST), George Miles
coalesced the vapors of human experience into a
viable and meaningful comprehension...

I dont know why Iggy is talking about Lightening:

Nor do I, but he's begining to remind me of w_tom, and that can't be
good.


--

Graham.
%Profound_observation%

replying to George Miles, Iggy wrote:
I'm talking about lightning, as one threat, because it's the most threatening
and most common. Lightning energizes the air and the earth. If you only
provide an outlet with no inlet, then you're dissipating lightning's residual
effect that is very weak. The facts about electricity are that it always
returns to the source of the electricity in seek of balance.

And therefore, if you add another rod and connection you're inviting more than
a residual of the energy, because you create both an inlet and an outlet, this
is very bad since neither you nor your devices can handle lightning's power.
Meaning, your current setup hasn't failed you and it has been confirmed to be
working properly. Don't fix what ain't broken and spray some herbicide around
the earth rod so you stop bumping into it.

--
for full context, visit https://www.homeownershub.com/uk-diy...s-1258572-.htm

replying to John Rumm, Iggy wrote:
1 - I didn't go off on any tangent. You seem to think Earthing is only ever a
1-way road and here you are telling people that I'm talking gibberish by
saying some appliances are Earthed, just to then confirm and tell me they're
Earthed...I know, I said it. You saying it to tell me I'm wrong is absurd.
That's how and why they get fried in a flawed Earthing setup.

2 - Like I said, if you aren't adding a 2nd rod and connection you aren't
supplying an inlet and are only supplying an outlet. However, by breaching the
building's natural insulation from what's going on outside, you now draw and
bring the outside in to create instead of avoid the hazard.

3 - Yes, adding another connection to the wiring system will effect everything
attached to it, because you're providing an in and out loop for the energy to
travel. Plumbing isn't providing any electrical source and is Earthed by
itself being in the Earth. Again, no inlet provided and only an outlet.

4 - Yes, this is what he has, in parallel or ONLY connected to each other with
just 1-connection. This, is extremely different than having multiple
connections to multiple rods...a proven disaster.

5 - Sorry, I misunderstood.

6 - Not where I'm from. Never ever should an electrical wiring system or
structure protection system be connected to a lightning protection system.
They are to be separate and even distanced from each other to avoid sharing
lightning's charge. I saw nothing to the contrary in your document, they make
it very clear that the lightning system shall have its own separated and
dedicated Earthing rods.

7 - See - 5.6.1 - What is protective multiple earthing? at
https://www.tlc-direct.co.uk/Book/5.6.1.htm this very clearly restricts the
use to the Utility Supplier and the last 2 sentences lock it out of public use.

8 - I've said my piece, you may have the last word.

--
for full context, visit https://www.homeownershub.com/uk-diy...s-1258572-.htm

On 26/12/2017 23:44, Iggy wrote:

replying to John Rumm, Iggy wrote:

You know it would be very much easier to follow your posts if you could
quote selectively.

(that daft web site you use, does let you quote - just select the text
of the message you are replying to before you start entering your
response and it will quote the source material)

1 - I didn't go off on any tangent.
You seem to think Earthing is only ever a
1-way road and here you are telling people that I'm talking gibberish by
saying some appliances are Earthed, just to then confirm and tell me
they're Earthed...I know, I said it. You saying it to tell me I'm wrong is absurd.
That's how and why they get fried in a flawed Earthing setup.

I was pointing out to you that what you claimed the additional earth
electrode could do (i.e. that it could bring a potential from outside
the building into it) was already being done.

Hence the additional electrode makes no difference.

2 - Like I said, if you aren't adding a 2nd rod and connection you aren't
supplying an inlet and are only supplying an outlet. However, by
breaching the building's natural insulation from what's going on outside, you now draw
and bring the outside in to create instead of avoid the hazard.

ISTM that you don't understand how main equipotential bonding is used
and configured in UK electrical systems.

There is a summary he

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

3 - Yes, adding another connection to the wiring system will effect
everything attached to it, because you're providing an in and out loop for the
energy to travel. Plumbing isn't providing any electrical source and is Earthed by
itself being in the Earth. Again, no inlet provided and only an outlet.

Something connected to earth *is* a source of electrical potential.
Also, due to the presence of main equipotential bonds like those which
connects the water supply pipework to the main earthing terminal and
hence to the earth electrode in a TT system, there is already an
internal earth connection.

4 - Yes, this is what he has, in parallel or ONLY connected to each
other with just 1-connection. This, is extremely different than having multiple
connections to multiple rods...a proven disaster.

Connections to multiple earth electrodes may be made by a single
unbroken conductor which loops to each in turn, or via individual
dedicated conductors. Both are acceptable.

5 - Sorry, I misunderstood.

You misunderstood what?

6 - Not where I'm from.

Where are you from exactly? It does have a significant relevance if its
not the UK, since wiring practices and codes vary significantly around
the world. Advice based on what is say common practice in the US would
be of little relevance to the UK for example.

Never ever should an electrical wiring system or
structure protection system be connected to a lightning protection system.

That explicitly contradicts the requirements specified in BS 7430 "Code
of practice for earthing of electrical installations".

I quote verbatim:

"6.4 Protective equipotential bonding

NOTE 1 The protective measure automatic disconnection of supply, requires:

a) automatic disconnection in the event of a fault to earth;
b) protective earthing (to facilitate this); and
c) protective equipotential bonding to reduce touch voltages.

Where the automatic disconnection of supply is adopted, protective
equipotential bonding is recommended (see Figure 6), whatever the type
of supply system. Bonding, by means of main equipotential bonding
conductors, of extraneous-conductive-parts to the main earthing terminal
of the installation is recommended; these extraneous-conductive-parts
include:

a) water installation pipes;
b) gas installation pipes;
c) other installation pipework and ducting;
d) central heating and air conditioning systems;
e) exposed metallic structural parts of the building structure; and
f) other metallic parts such as cable trays and cable ladder racks.

Connection of a lightning protection system to the protective
equipotential bonding should be made in accordance with BS EN 62305-4.

#### my emphasis:

NOTE 2 BS EN 62305-4 requires that a bond is made between the lightning
protecting system and the installation equipotential bonding system. The
responsibility for specifying and installing this bond is that of the
organization responsible for the lightning protection system.

####"

(not that for completeness, lighting protection systems are very rarely
installed for domestic properties in the UK)

They are to be separate and even distanced from each other to avoid sharing
lightning's charge. I saw nothing to the contrary in your document, they
make it very clear that the lightning system shall have its own separated and
dedicated Earthing rods.

They have separate electrodes, however the are also bonded together.
This helps mitigate shock risk in the event of a strike by ensuring that
all accessible conductive paths will be elevated to the same (or
similar) electrical potential.

7 - See - 5.6.1 - What is protective multiple earthing? at
https://www.tlc-direct.co.uk/Book/5.6.1.htm this very clearly restricts the
use to the Utility Supplier and the last 2 sentences lock it out of
public use.

Most new UK supply installations are PME (TN-C-S) (Older properties
tended to more commonly be TN-S).

Significantly fewer properties use TT Earthing (i.e have to supply their
own earthing system - typically via earth rods etc[2])

So PME is widely installed for public use. The limitations spelt out at
the end of the page you cited (i.e. "The difficulty of ensuring that
bonding requirements are met on construction sites means that PME
supplies must not be used. Electricity Supply Regulations forbid the use
of PME supplies to feed caravans and caravan sites.") does not really
have any bearing on the current discussion, however there is a fuller
explanation here if you are interested:

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

Explanation of the general earthing terms he

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

[2] http://wiki.diyfaq.org.uk/index.php/TT_Earthing

8 - I've said my piece, you may have the last word.

For the avoidance of doubt, I am not picking on you are arguing for the
sake of it, it is just that the advice you are offering does seem to be
at odds with standard wiring practices here in the UK. I accept that
things are done differently elsewhere.


--
Cheers,

John.

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On 26/12/2017 23:44, Iggy wrote:

replying to George Miles, Iggy wrote:
I'm talking about lightning, as one threat, because it's the most
threatening and most common.

Dangerous lightening strikes in the UK are extremely rare. There are an
average of around 2 fatalities a year, and perhaps 30 injuries.

(contrast that to say the US where they have something like 25 times
that rate with only 5 times the population)

--
Cheers,

John.

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

On 27/12/17 04:34, John Rumm wrote:
Dangerous lightening strikes

I wish some Lightening would strike me. I am getting old and fat.


--
No Apple devices were knowingly used in the preparation of this post.

In article , Andrew97d-
says...


Well I was thinking of those programs like Homes Under the hammer, which
was one situation where a house bought at auction turned out to have
an old well inside the property.

It was dry-ish

Reminds me of a house I visited in Didcot a year or two ago.

The well is quite deep and still has water at the bottom!

--

Terry

---
This email has been checked for viruses by AVG.
http://www.avg.com

On Tue, 26 Dec 2017 21:24:19 +0000, Roger Hayter wrote:

Alan wrote:

O
No, it'd be no good, as it would blow fast enough to stop any
lightening


WOULDNT Doh.

Since we're doing corrections, can we correct 'lightning' without an e
please?

I was hoping *someone* was going to pick that up. :-)

--
Johnny B Good

On Mon, 25 Dec 2017 13:56:37 -0000 (UTC), Cursitor Doom
coalesced the vapors of human experience into a
viable and meaningful comprehension...

On Mon, 25 Dec 2017 07:22:36 -0600, Alan wrote:

What is your earth rod resistance now?
Adding an extra rod is not guaranteed to lower the total resistance.
If you are currently getting 10 ohms than adding another rod will not
really help, however if you have 150ohms or so, then an extra, or deeper
rod may well help.

Should really be earth loop *impedance* tested at 50Hz.

True, but I doubt the inductive and capacitive reactance components
are too significant. I'm willing to learn though.


--

Graham.
%Profound_observation%