household ground system

[Ken Taylor]

A comprehensive example of someone who knows Jack about a subject and spouts
anyway. Time to killfile.

Ken

"w_tom" <w_tom1@hotmail.com> wrote in message
news:40428DF0.8599986A@hotmail.com...

Is earth of 25 ohms at 60 hz and some amps also 25 ohms at
thousands of amps? Of course not. Resistance is only linear
within certain limits. No resistance remains linear -
constant - once we apply extreme voltages or currents. One
important parameter that defines a complete breakdown of
linear resistance is called breakdown voltage. The NEC only
defines continuity of earth within the current and frequency
ranges used by utilities.

Measure the resistance across a fluorescent tube. A 25 watt
tube must be on the order of 2000 ohms to conduct sufficient
AC electric currents. So why is that resistance in excess of
10 megohms? Again, resistance in earth and in that
fluorescent tube, is not constant for all electrical
parameters.

10 centimeters of air has multi-megohms of resistance. Many
kilometers of megohm resistors in series clearly means that
lightning cannot pass through air. And yet those many megohm
resistors become an excellent conductor of 2kamp or 20 kamp
lightning currents. How can this be? As megohms of air
become a good conductor, then so does 25 ohms of earth become
an even better conductor.

Lightning could travel 5 kilometers diagonally over to
earthborne charges - to complete an electric circuit. But a
shorter electrical path is 3 kilometers of air down to earth
and 4 kilometers through earth because, during the current
transient, earth become far more conductive than '25 ohms'.
This even though 300,000 multi-megohm resistors in air become
perfectly good conductors.

I never avoided that 25 ohms. A responsible person never
asked about those 25 ohms. When that earth resistance at 60
hz and a few amps becomes less, then that same soil becomes
even more conductive during a CG lightning strike. 25 ohms
verses other soils is a good indication as to how conductive
soil may be also during strike. But earth is not at 25 ohms
when conducting the most common 2 Kamp or 10 Kamp lightning
strikes. Earth, like air, becomes extremely conductive which
is why lighting seeks earth ground and which is why good earth
grounds make lightning rods and 'whole house' protectors so
effective.

Rather than criticize, please cite specific reference where
citation was misrepresented. Lem Instruments was only
provided as a reference on how earth conductivity is measured
- in the electrical domain defined by NEC. It was not cited
to sell anything. In the meantime NEC does not even define
how that 25 ohms should be measured. Earthing system does not
measure 25 ohms during the CG strike just like air does not
maintain multi-megohms of resistance.

Joe Van wrote:
Well actually the references do seem a bit .... shall we say
Careless but then like all the references w_tom comes up with
it is trying to sell something. On the whole though it does not
appear too bad - on a cursory flick through it there are no
glaring errors.

Of course it does point out a small fact that w_tom keeps carefully
avoiding and that is that the resistance to earth for a single
earth stake is considered by the NEC is less than 25 Ohms -
calculate the EPR on that of a Lightning strike of say a
conservative 10,000 Amps.
...

 

[Brian Goldsmith]

"w_tom" <w_tom1@hotmail.com> wrote

"Is earth of 25 ohms at 60 hz and some amps also 25 ohms at
thousands of amps"

and a whole lot of other utter drivel.


What a moron!Ken Taylor was correct in his conclusion,"Time to
killfile"!!!


Brian Goldsmith.

 

[w_tom]

Instead of posting emotion, show the world that 25 ohms
remains constant at all voltages and currents. Demonstrate
that resistance is always linear even at breakdown voltages.
Emotion, as posted, only says you respond like the adult who
is still a child. Instead, post facts that earth is constant
25 ohms for all voltages. Prove that air resistance and earth
resistance always remains constant. Don't waste good
bandwidth with your tirade. Only children post tirades and
run for the protection of a killfile. Show us how earth and
air remain at a constant resistance no matter what. You
cannot. But try anyway.

Brian Goldsmith wrote:

"w_tom" <w_tom1@hotmail.com> wrote
"Is earth of 25 ohms at 60 hz and some amps also 25 ohms at
thousands of amps"

and a whole lot of other utter drivel.

What a moron!Ken Taylor was correct in his conclusion,"Time to
killfile"!!!

 

[Joe Van]

Once again "w_tom" <w_tom1@hotmail.com> shows his complete ignorance of
Lightning in message news:4043B634.60DFF65A@hotmail.com...

Busy Top Posting to avoid the real issues and misconstrue what was said I
see....

Instead of posting emotion, show the world that 25 ohms
remains constant at all voltages and currents. Demonstrate
that resistance is always linear even at breakdown voltages.
Emotion, as posted,

This from the creature who rushes to accuse other people of his own
Failings - that is a complete lack of knowledge and understanding of basic
Physics and Electrical Theory.

only says you respond like the adult who
is still a child.

More of what Psychologists refer to as 'Projection' that is accusing other
people of their own Failings. w_tom demonstrates time and time again his
desire to wax Lyrical on a subject he is almost completely ignorant of -
Lightning protection. If this is not Juvenile behaviour what is ?

Instead, post facts that earth is constant
25 ohms for all voltages.

That Earth resistance remains at a relatively high Impedance during a
Lightning strike is illustrated by a Very Very Simple concept called EPR (or
by the Americans GPR) this is a concept that has been well known since
Benjamin Franklins time and the effects of which had been often observed by
Farmers with the death of Live stock in fields which have suffered Lightning
Strikes. The effects of EPR are most likely often observed by the Farmers on
the Newsgroups that let w_tom pose as an all knowing Guru but it still
remains a foreign Concept to w_tom.

The really odd thing is that most sane Surge arrestor manufacturers in fact
go to long lengths to discuss this Phenomona in their Literarture with many
even pointing out that Resistance to Earth from an Earth stake (even during
the conditions of a Lightning strike) is still sufficent to cause an EPR of
tens of Thousands of Volts.

In fact EPR is well known to anyone who installs Earth Systems for 'High
reliabilty installations' such as Telephone Exchanges and Radio transmitters
so it seems very odd that w_tom is not aware of the concept or the
limitations of Earth Stakes especially if he is the Guru on Surge
protections his Pontifications on the subject imply. In fact even w_toms
much admired experts Poly Phaser talk about GPR :
http://www.polyphaser.com/ppc_PEN1014.asp. but then even they admit to the
limitations of their knowledge and refer Readers on to:
http://www.gpr-expert.com/

Of course the real reason why w_tom refuses to admit the exsistance of Earth
resistance through the analysis of the EPR phonemenon is that this would be
counter to most of w_toms arguments about the efficacy of MOVs and the
efficacy of a 'good Earth'.
w_tom has of course touched briefly on his lack of knowledge on Earthing
Systems with a Statement he made previously in this Thread (and I quote) :
"Unfortunately earthing is the art of protection. Not possible
to fully test the installation until after an event. When
failure does happen, then humans return to learn why their
failure permitted the failure."

Since he does not understand the Science behind Earthing he relegates it to
the status of an 'Art' (probably in his mind a bit of a Black art) and
leaves the Earthing as an out for when his 'whole house Protection' Systems
fail to provide the 100% Protection w_tom claims.
Lightning Protection is a Science not an Art and Installers Like w_tom who
do not understand the Science are doomed to Failure from the beginning.

Prove that air resistance and earth
resistance always remains constant. Don't waste good
bandwidth with your tirade. Only children post tirades and
run for the protection of a killfile.

Unfortunately for w_tom whereas Brian has a demonstrable Track record of
knowing what he is talking about all w_tom has proven so far is that he is
an ignorant, Posturing Prat who knows very little about his chosen subject -
that of Lightning protection.
There are times when I suspect Kill filing the fool would be the best
solution but then I think off all the cases of Lightning damage I have seen
which would have been so easily prevented by good Realistic and honest
advice and I realise that w_tom has to be shown up for the ignorant fool
that he is.

Show us how earth and
air remain at a constant resistance no matter what. You
cannot. But try anyway.

Dont need to as it does not need to remain constant to be a serious issue -
but then I am probably being a bit unreasonable to expect w_tom to
understand this.

Regards
Joe Van

 

[Jim Jones]

w_tom <w_tom1@hotmail.com> wrote in message
news:4043B634.60DFF65A@hotmail.com...

Instead of posting emotion, show the world that 25
ohms remains constant at all voltages and currents.

Doesnt need to, you pig ignorant cretin.

Even if it drops by an order of magnitude at high currents,
you will STILL have a problem with KA currents, fuckwit.

Demonstrate that resistance is always linear even at breakdown voltages.

Completely irrelevant whether its linear or not. What
actually matters is what it might concievably change to.

Thanks for the completely superfluous proof that
you've never ever had a fucking clue about the basics.

Emotion, as posted, only says you
respond like the adult who is still a child.

Wota fucking wanker. No need to guess what the w in w_tom stands for.

Instead, post facts that earth is constant 25 ohms for all voltages.

Completely irrelevant whether it is or not.

Prove that air resistance and earth
resistance always remains constant.

Completely irrelevant whether it is or not.

What matters is the range it might vary over.

Its never gunna end up so low that KA currents wont
still be a massive problem voltage wise, fuckwit.

Don't waste good bandwidth with your tirade. Only
children post tirades and run for the protection of a killfile.

Pathetic, really.

Show us how earth and air remain at a constant resistance no matter what.

Completely irrelevant whether it is or not.

You cannot.

Completely irrelevant whether it is or not.

But try anyway.

Wota fucking wanker.

Brian Goldsmith wrote:
"w_tom" <w_tom1@hotmail.com> wrote
"Is earth of 25 ohms at 60 hz and some amps also 25 ohms at
thousands of amps"

and a whole lot of other utter drivel.

What a moron!Ken Taylor was correct in his conclusion,"Time to
killfile"!!!

 

[Vermin]

Pill Allison, just noticed your rambling reply to my post on Google
groups whilst searching for an old message of mine (you are kill filed
on my news reader).

I hate feeding trolls but here goes;

After being subject to a 3kA 8/20 surge a thermal fuse fails s/c this
way:

Put it in a hot box (carrying current) and subject it to a much higher
temperature than it is rated for.

It will not go o/c at all, not hours later, not days later.

Ergo it has failed s/c.

Understand now fool?

V - why do I bother?

 

[Phil Allison]

"Vermin" <Vermin@nowhere.com>

Pill Allison, just noticed your rambling reply to my post on Google
groups whilst searching for an old message of mine (you are kill filed
on my news reader).

I hate feeding trolls but here goes;

** Then you must be absolutely starving.

After being subject to a 3kA 8/20 surge a thermal fuse fails s/c this
way:

Put it in a hot box (carrying current) and subject it to a much higher
temperature than it is rated for.

It will not go o/c at all, not hours later, not days later.

Ergo it has failed s/c.

** So you say the lump of low melting point alloy inside that temperature
fuse will turn completely into a new high melting point conductive material.

Is it gold ? Uranium ?? Plutonium ???

Can WMDs be made this way ???

Are Arab terrorists aware of this ??????

The world needs your immediate answer.




.............. Phil

 

[Vermin]

On Wed, 03 Mar 2004 08:37:51 GMT, Vermin <Vermin@nowhere.com> wrote:

Reply to Phil (you'll be happy to know that as of now you are no
longer kill filed, we'll see for how long);

I'm pretty sure it's not alchemy you tripper, but lacking a mass
spectrometer I can't rule this out completely, other than by common
sense and this:

Cutting the device open after subjecting it to a surge shows that the
granules of sand (or whatever they are) the device is filled with have
become plated with metal.

I can only assume that surface tension around the grains is keeping
the thin layer of metal in place (but you know what assumptions are
the mother of).

Normally the metal should melt and flow between the grains, but with
such a fine coating stuck to the closely packed granules this does not
seem to happen.

Interestingly the low volt DC resistance does not change measurably.

I have not tried to overcurrent (they do have a max. I rating) a
device that has been subject to a surge but suspect that the rating of
this mode of o/c will have been substantially altered.

I'll do a test in a week or so when the test room is free (currently
full of bits of a half built 70kA 25kV 8/20 gen.).

Here 'tis: http://www.webclot.com/high_volt/images/DSCF0008.JPG for
those interested.

(note cigarette packet in upper left for scale).

V,

 

[Phil Allison]

"Vermin" <Vermin@nowhere.com>

Reply to Phil (you'll be happy to know that as of now you are no
longer kill filed, we'll see for how long);

I'm pretty sure it's not alchemy you tripper, but lacking a mass
spectrometer I can't rule this out completely, other than by common
sense and this:

** Common sense ?????????????

No sign of that from you.

Cutting the device open after subjecting it to a surge shows that the
granules of sand (or whatever they are) the device is filled with have
become plated with metal.

** Your unsupported assertions are a worthless as dog shit.




.............. Phil

 

On Thu, 04 Mar 2004 11:05:26 GMT, Vermin <Vermin@nowhere.com> wrote:

On Wed, 03 Mar 2004 08:37:51 GMT, Vermin <Vermin@nowhere.com> wrote:
I'll do a test in a week or so when the test room is free (currently
full of bits of a half built 70kA 25kV 8/20 gen.).

Here 'tis: http://www.webclot.com/high_volt/images/DSCF0008.JPG for
those interested.

(note cigarette packet in upper left for scale).

V,

Is that for Big Bertha's Bigger Sister?

Btw, I enjoyed Mindy's Misadventures.

 

[Michael]

Vermin <Vermin@nowhere.com> wrote in message news:<hjrd40p5fapepgr6673qrqvstmp9lpc4em@4ax.com>...

On Wed, 03 Mar 2004 08:37:51 GMT, Vermin <Vermin@nowhere.com> wrote:

Reply to Phil (you'll be happy to know that as of now you are no
longer kill filed, we'll see for how long);

I'm pretty sure it's not alchemy you tripper, but lacking a mass
spectrometer I can't rule this out completely, other than by common
sense and this:

Cutting the device open after subjecting it to a surge shows that the
granules of sand (or whatever they are) the device is filled with have
become plated with metal.

I can only assume that surface tension around the grains is keeping
the thin layer of metal in place (but you know what assumptions are
the mother of).

Normally the metal should melt and flow between the grains, but with
such a fine coating stuck to the closely packed granules this does not
seem to happen.

Interestingly the low volt DC resistance does not change measurably.

I have not tried to overcurrent (they do have a max. I rating) a
device that has been subject to a surge but suspect that the rating of
this mode of o/c will have been substantially altered.

I'll do a test in a week or so when the test room is free (currently
full of bits of a half built 70kA 25kV 8/20 gen.).

Here 'tis: http://www.webclot.com/high_volt/images/DSCF0008.JPG for
those interested.

(note cigarette packet in upper left for scale).

V,

What is 8/20 ?

 

[Richard Freeman]

"Michael" <michael@clift.com.au> wrote in message
news:ec96e13a.0403041532.3595f2b1@posting.google.com...

Vermin <Vermin@nowhere.com> wrote in message
news:<hjrd40p5fapepgr6673qrqvstmp9lpc4em@4ax.com>...
On Wed, 03 Mar 2004 08:37:51 GMT, Vermin <Vermin@nowhere.com> wrote:

Reply to Phil (you'll be happy to know that as of now you are no


Here 'tis: http://www.webclot.com/high_volt/images/DSCF0008.JPG for
those interested.

(note cigarette packet in upper left for scale).

V,

I am surprised that anyone else has followed this discussion this far !!
learning Lots ?

What is 8/20 ?

8uS/20uS an assumption by Lightning arrestor (MOV) manufacturers that
Lightning consists of a short spike lasting 8uS followed by a Lower follow
on current lasting 20uS or in other words an indication of how long the
average MOV lasts in a Lightning Strike (which usually lasts mS at the
best - often up to 100 or 200 mS and this is assuming a single stroke only )
the real joke is that MOVs are fairly slow to start conducting and have
usually barely started to conduct by the time 8uS is up. Oh well I guess it
stops the MOV from failing ;-) so that w_tom types can blame Earthing.

Regards
Richard Freeman
( I am not an Expert in Lightning but I sure as heck know a lot more than
w_tom)

 

[Vermin]

On Fri, 5 Mar 2004 13:10:41 +1100, "Richard Freeman"
<deletethisrichard@atps.net> wrote:

"Michael" <michael@clift.com.au> wrote in message
news:ec96e13a.0403041532.3595f2b1@posting.google.com...
Vermin <Vermin@nowhere.com> wrote in message
news:<hjrd40p5fapepgr6673qrqvstmp9lpc4em@4ax.com>...
On Wed, 03 Mar 2004 08:37:51 GMT, Vermin <Vermin@nowhere.com> wrote:

Reply to Phil (you'll be happy to know that as of now you are no


Here 'tis: http://www.webclot.com/high_volt/images/DSCF0008.JPG for
those interested.

(note cigarette packet in upper left for scale).

V,

I am surprised that anyone else has followed this discussion this far !!
learning Lots ?

What is 8/20 ?

8uS/20uS an assumption by Lightning arrestor (MOV) manufacturers that
Lightning consists of a short spike lasting 8uS followed by a Lower follow
on current lasting 20uS or in other words an indication of how long the
average MOV lasts in a Lightning Strike (which usually lasts mS at the
best - often up to 100 or 200 mS and this is assuming a single stroke only )
the real joke is that MOVs are fairly slow to start conducting and have
usually barely started to conduct by the time 8uS is up. Oh well I guess it
stops the MOV from failing ;-) so that w_tom types can blame Earthing.

Regards
Richard Freeman
( I am not an Expert in Lightning but I sure as heck know a lot more than
w_tom)

Not an assumption at all. It just depends where you measure the

current. There are also 10/700 10/1000 and 10kHz ring wave standard
test pulses for different points in wiring systems.
It is true that they are not an actual representation of every
lightning strike. Especially as nearly all strikes consist of multiple
return pulses.
However, they are a damn fine "standard" way to compare different
protection methods, and many years experience of actual strike shows
that the present system is adequate in estimating the protection level
provided.
V.

 

[Vermin]

On Thu, 4 Mar 2004 22:53:08 +1100, "Phil Allison"
<philallison@optusnet.com.au> wrote:

"Vermin" <Vermin@nowhere.com

Reply to Phil (you'll be happy to know that as of now you are no
longer kill filed, we'll see for how long);

I'm pretty sure it's not alchemy you tripper, but lacking a mass
spectrometer I can't rule this out completely, other than by common
sense and this:


** Common sense ?????????????

No sign of that from you.

No none at all.

Other than actual testing of physical devices rather than sitting on
my arse spouting unsubstantiated crap like yourself.

Cutting the device open after subjecting it to a surge shows that the
granules of sand (or whatever they are) the device is filled with have
become plated with metal.


** Your unsupported assertions are a worthless as dog shit.

As I suspected your drivel has not improved, at all. Back to the kill
file you go.

Go and do some tests yourself Pil, rather than hiding behind your PC
knocking others findings based on nothing more than your
unsubstantiated substandard opinion.

V- why do I bother?

 

[Vermin]

On Thu, 04 Mar 2004 23:22:48 +1100, dmmilne@home.now wrote:

Is that for Big Bertha's Bigger Sister?

Nagh, the new surge gen may look impressive, but doesn't have the

staying power of BB.

Btw, I enjoyed Mindy's Misadventures.

Cheers, I should do a follow up on that as I am now getting 1.5m
streamers from BB, about another third again of what is shown in those
pics.

For them wot can't fiddle with URLs like dmm:

http://www.webclot.com/b3ta/Mindys_Misadventure/

V.

 

[Phil Allison]

"Vermin" <Vermin@nowhere.com


No none at all.
Other than actual testing of physical devices rather than sitting on
my arse spouting unsubstantiated crap like yourself.

** What bloody tests ??

Ones only ***YOU*** know about apparently.

That is as "unsubstantiated" as it is possible to get.

Cutting the device open after subjecting it to a surge shows that the
granules of sand (or whatever they are) the device is filled with have
become plated with metal.


** Your unsupported assertions are a worthless as dog shit.


As I suspected your drivel has not improved, at all. Back to the kill
file you go.

** Back to the Tasmanian lunatic asylum with you - Mr Schizoid.

You can meet up with " W Tom " there one day.




............. Phil

 

[Richard Freeman]

"Vermin" <Vermin@nowhere.com> wrote in message
news:54bg40dobvh3ehkvs2coib6ms9i47hihkg@4ax.com...

On Fri, 5 Mar 2004 13:10:41 +1100, "Richard Freeman"
deletethisrichard@atps.net> wrote:


"Michael" <michael@clift.com.au> wrote in message
news:ec96e13a.0403041532.3595f2b1@posting.google.com...
Vermin <Vermin@nowhere.com> wrote in message
news:<hjrd40p5fapepgr6673qrqvstmp9lpc4em@4ax.com>...
On Wed, 03 Mar 2004 08:37:51 GMT, Vermin <Vermin@nowhere.com> wrote:

Reply to Phil (you'll be happy to know that as of now you are no


Here 'tis: http://www.webclot.com/high_volt/images/DSCF0008.JPG for
those interested.

(note cigarette packet in upper left for scale).

V,

I am surprised that anyone else has followed this discussion this far !!
learning Lots ?

What is 8/20 ?

8uS/20uS an assumption by Lightning arrestor (MOV) manufacturers that
Lightning consists of a short spike lasting 8uS followed by a Lower
follow
on current lasting 20uS or in other words an indication of how long the
average MOV lasts in a Lightning Strike (which usually lasts mS at the
best - often up to 100 or 200 mS and this is assuming a single stroke
only )
the real joke is that MOVs are fairly slow to start conducting and have
usually barely started to conduct by the time 8uS is up. Oh well I guess
it
stops the MOV from failing ;-) so that w_tom types can blame Earthing.

Regards
Richard Freeman
( I am not an Expert in Lightning but I sure as heck know a lot more than
w_tom)

Not an assumption at all. It just depends where you measure the
current.

hmmm no you are right it is probably a very carefully calculated wave form
decided on by Surge arrestor manufacturers to be the briefest times that the
current pulse of Lightning has ever been measured for - in order to give
their arrestors the maximum opportunity to survive the test.

There are also 10/700 10/1000 and 10kHz ring wave standard
test pulses for different points in wiring systems.
It is true that they are not an actual representation of every
lightning strike. Especially as nearly all strikes consist of multiple
return pulses.

Yep O.k your knowledge of Lightning is evidently Much higher than that of
w_toms I will now accept that he and you are indeed different People;-)
I would tend to Argue however that 8/20 is not even representative of a
typical Ground strike and therefore only really any good as an 'Apples with
Apples' comparison for different protectors and not really an adequate
indication of the degree of protection offered in a real Lightning strike.

However, they are a damn fine "standard" way to compare different
protection methods,

I will accept that they are a Method of comparing Different MOVs with a
standard Test.

and many years experience of actual strike shows
that the present system is adequate in estimating the protection level
provided.

Hmmmmm I will choose to disagree slightly here (of course it is possible my
interpretation of what you are saying is different to what you intend) as I
have seen way to much fried Equipment and smoked Surge arrestors
(understatement here they have often been blown into very tiny fragments) to
believe that most Surge arrestors provide any more than very Basic
protection - only of any use against Distant Strikes. As a result my opinion
of Protection level provided tends to be that Protection typically provided
is to be considered as a line of last resort only.

I have to confess I am still having trouble with the concept of a Thermal
Fuse failing or being fused Short but until I can repeat the test for myself
........

Can you describe the test in which you established this in more detail ? was
the thermal fuse tested with the pulse alone ? or in series with a MOV ? was
this test repeated ? were different brands of Thermal fuse tried ?

Regards
Richard Freeman