I
Ilona Kurzhals
- Jan 1, 1970
- 0
Hi,
How to protect my tiny little solar equipment from induction (thunder and
lightning)?
How to protect my tiny little solar equipment from induction (thunder and
lightning)?
R
Richard P.
- Jan 1, 1970
- 0
Ilona Kurzhals said:
You can buy lightning arrestors that can do the job, but note that they are not a guarantee that
they will work. Nothing can dump a million amps @ hundreds of thousands of volts to ground in a
nanosecond. But proper installation has shown these to work rather effectively otherwise.
C
Calvin
- Jan 1, 1970
- 0
Hi,Richard said:
I think your statements over the currents involved in lightning and it's rise
time are a bit alarmist !
A typical lightning discharge has a wave shape with a 100ns to several uS rise
time and about a 20uS fall off - with several such sharp 'spikes' in a total
event (hence why lightning is observed to 'flicker' to the human eye)
The currents involved are typically in the range of 50,000 amps, with really big
ones (out of the high end of the 'curve') registering in the 200,000 amp range.
Correctly installed lightning protection systems can easily deal with this
situation. Many companies specialise in such equipment. See Erico www.erico.com
as an example.
As to voltages in lightning, that is a more difficult thing to quantify - for
the purposes of protection however it is immaterial, the potential rise in the
ground and the surrounding area caused by the discharge current is what does the
damage.
If you were to measure the lightning bolt from 'end to end' (utterly impossible)
the voltage would be in the billions of volts. The voltage rise at the point of
contact of the discharge however is typically a few hundred to thousands of
volts, depending upon the resistance to Earth of the discharge point, and the
exact value follows ohms law of V = I x R, where V is the voltage produced, I is
the current, and R is the resistance to ground.
So the bottom line is a lightning protection scheme is STRONGLY Dependant upon a
properly designed, installed and maintained earthing system to carry the
discharge current safely away.
There are national standards available that describe design, install etc.. in
minute detail. Here in Australia (where I am) lightning protection is standard
AS1768.
Calvin.
R
Robert Morein
- Jan 1, 1970
- 0
Unless it's a superbolt:Calvin said:
http://nis-www.lanl.gov/nis-projects/forte_science/html/LA-UR-99-1685/superbolt.html
C
Calvin
- Jan 1, 1970
- 0
Hi Robert,
Figure 5 of that article basically bears out the figure I quoted, if anything
I'd been a bit pessimistic.
The peak of the curve is at about 50kA (50,000 amps) with an EXTREMELY small
number of Vertical Current incidents reaching the 200kA (200,000 amps) range
(probably less than 0.1% using a quick 'calibrated eyeball' examination of the
graph)
The powers involved however are large since power is calculated by P = V x I,
where P is the power in watts, I is the current in amps, and V is the voltage in
volts. As I said, the voltage 'end to end' of the discharge is the value of
voltage being used in these calculations, hence the discharge powers reading in
the GW (gigawatts = billion watts)
Most of the power is dissipated as heat, light and other EM spectrum components
in the atmosphere (hence the thunder, lightning static on radios and the bright
flash) and only an extremely small proportion is actually delivered to the
ground where the lightning strikes.
The actually energy of the discharge in not that large, since the discharge
usually only lasts for a fraction of a second.
I forgot to mention the discharge duration in my last posting. A typical bolt
has fairly sharp rise time (a few hundred nanseconds to a few microseconds) a
duration of a few hundred microseconds, and a fall time of around 20
microseconds. The total strike incident usually involves several discharges in
rapid succession with gaps in between each discharge of maybe 50 to a couple of
hundred milliseconds. The whole event usually lasts a fraction of a second,
though I have personally seen events here in Australia run for as long as 3 to 5
seconds !
The Energy, measured in Joules is calculated by:
Energy imparted by a lightning discharge:
E = P x t E=energy (in joules)
P=power (in watts)
t=time (in seconds)
Just to aid people in understanding the values in the charts presented in this
article the formulas you need to make sense of it all (in addition to above) are:
Charge delivered:
Q = I x t Q=charge (in coulombs)
I=current (in amperes)
t=time (in seconds)
A typical lightning event shifts a few tens of coulombs of charge maximum.
Power developed:
P = V x I P=power (in watts)
V=voltage (in volts)
I=current (in amps)
The computation of power developed borders on impossible, since you would need
to know the voltage potential 'end to end' of the discharge path, which is
totally impractical to measure. The article quoted by Robert is deriving their
figures for power based on estimations of the brilliance of the lightning
'flash' as recorded by an observational satellite.
Potential rise at the strike point: (what we were talking about in this
newsgroup thread originally)
V = I x R V=voltage (in volts)
I=current 9in amperes)
R=resistance to Earth (in ohms)
Calvin.
Figure 5 of that article basically bears out the figure I quoted, if anything
I'd been a bit pessimistic.
The peak of the curve is at about 50kA (50,000 amps) with an EXTREMELY small
number of Vertical Current incidents reaching the 200kA (200,000 amps) range
(probably less than 0.1% using a quick 'calibrated eyeball' examination of the
graph)
The powers involved however are large since power is calculated by P = V x I,
where P is the power in watts, I is the current in amps, and V is the voltage in
volts. As I said, the voltage 'end to end' of the discharge is the value of
voltage being used in these calculations, hence the discharge powers reading in
the GW (gigawatts = billion watts)
Most of the power is dissipated as heat, light and other EM spectrum components
in the atmosphere (hence the thunder, lightning static on radios and the bright
flash) and only an extremely small proportion is actually delivered to the
ground where the lightning strikes.
The actually energy of the discharge in not that large, since the discharge
usually only lasts for a fraction of a second.
I forgot to mention the discharge duration in my last posting. A typical bolt
has fairly sharp rise time (a few hundred nanseconds to a few microseconds) a
duration of a few hundred microseconds, and a fall time of around 20
microseconds. The total strike incident usually involves several discharges in
rapid succession with gaps in between each discharge of maybe 50 to a couple of
hundred milliseconds. The whole event usually lasts a fraction of a second,
though I have personally seen events here in Australia run for as long as 3 to 5
seconds !
The Energy, measured in Joules is calculated by:
Energy imparted by a lightning discharge:
E = P x t E=energy (in joules)
P=power (in watts)
t=time (in seconds)
Just to aid people in understanding the values in the charts presented in this
article the formulas you need to make sense of it all (in addition to above) are:
Charge delivered:
Q = I x t Q=charge (in coulombs)
I=current (in amperes)
t=time (in seconds)
A typical lightning event shifts a few tens of coulombs of charge maximum.
Power developed:
P = V x I P=power (in watts)
V=voltage (in volts)
I=current (in amps)
The computation of power developed borders on impossible, since you would need
to know the voltage potential 'end to end' of the discharge path, which is
totally impractical to measure. The article quoted by Robert is deriving their
figures for power based on estimations of the brilliance of the lightning
'flash' as recorded by an observational satellite.
Potential rise at the strike point: (what we were talking about in this
newsgroup thread originally)
V = I x R V=voltage (in volts)
I=current 9in amperes)
R=resistance to Earth (in ohms)
Calvin.
R
Richard P.
- Jan 1, 1970
- 0
I stand corrected on the lightning current/voltage info. But I would think that the end result
would still be the same whether it was 50KA or 1MA. The gist of my message was not to be "alarmist"
but to point out that dumping that much power is difficult but that products do exist that can
assist in the safe transfer of such power.
By the way, you helped me win a bet. Judging by the responses to peoples questions on here lately
(and the alt.homepower group) I figured someone would first reply with a correction to my post. It
got me a bottle of fine Canadian Crown Royal. Thanks!
would still be the same whether it was 50KA or 1MA. The gist of my message was not to be "alarmist"
but to point out that dumping that much power is difficult but that products do exist that can
assist in the safe transfer of such power.
By the way, you helped me win a bet. Judging by the responses to peoples questions on here lately
(and the alt.homepower group) I figured someone would first reply with a correction to my post. It
got me a bottle of fine Canadian Crown Royal. Thanks!
W
William P.N. Smith
- Jan 1, 1970
- 0
Richard P. said:By the way, you helped me win a bet. Judging by the responses to peoples questions on here lately
(and the alt.homepower group) I figured someone would first reply with a correction to my post. It
got me a bottle of fine Canadian Crown Royal. Thanks!
This is Usenet, that's a sucker bet.
G
Gymy Bob
- Jan 1, 1970
- 0
Don't let the grounding folk scare ya.
The idea is not to take the lightning (if that's what you mean by induction)
to ground but bring the ground to the same potential as everything else (no
potential difference). Connect your panels and frames back to the
electronics frames to your phone line input ground to your service panel
ground to your etc... and then take the whole thing with a radial connection
to the earth ground. If you are in a high static discharge area then drive
more ground rod and connect them all with heavy 2/0 or better copper.
NOTE: do not pass ground wires through metal holes or cable clamps with two
screws on a metal surface. These act like chokes and will stop the Ghz
frequencies incurred in lightning and may as well not be connected.
The idea is not to take the lightning (if that's what you mean by induction)
to ground but bring the ground to the same potential as everything else (no
potential difference). Connect your panels and frames back to the
electronics frames to your phone line input ground to your service panel
ground to your etc... and then take the whole thing with a radial connection
to the earth ground. If you are in a high static discharge area then drive
more ground rod and connect them all with heavy 2/0 or better copper.
NOTE: do not pass ground wires through metal holes or cable clamps with two
screws on a metal surface. These act like chokes and will stop the Ghz
frequencies incurred in lightning and may as well not be connected.
M
m II
- Jan 1, 1970
- 0
Gymy said:
Dear God..What will I do? My electrical service is just oozing with
ground wires going through holes.
They are AIR filled holes, however, not the METAL holes you describe.
What exactly does a metal hole look like? Is it similar to the
semiconductor ones, but MORE 'conductory'?
mike
G
Gymy Bob
- Jan 1, 1970
- 0
You can run but ya cannot hide.
m II said:
C
Calvin
- Jan 1, 1970
- 0
Hi Gymy Bob,
Part of what I posted originally was the reference to the national standards on
this subject - Like AS1768 here in Australia.
A whole section in this document is devoted to the subject of 'equi-potential
bonding' which is what you are referring to. This is an extremely important
aspect in the overall protection strategy.
Calvin.
Part of what I posted originally was the reference to the national standards on
this subject - Like AS1768 here in Australia.
A whole section in this document is devoted to the subject of 'equi-potential
bonding' which is what you are referring to. This is an extremely important
aspect in the overall protection strategy.
Calvin.
C
Calvin
- Jan 1, 1970
- 0
Glad to help you win a bet
Lightning, and protection of equipment and buildings from it, is a subject I
have studied in some detail and while I could never claim 'expert' status, I
think I know enough to be able to point people in the right direction on their
quest for knowledge.
The article you cited was very interesting, using the 'flash brilliance' and
duration to measure the energy output is innovative. There are just that many
areas of the physics of lightning that we don't understand. Have a look, if you
are interested, at the web site for the University of New Mexico and the
'Langmuir Laboratory' in particular. They are world leaders in research in this
area.
Calvin.
Lightning, and protection of equipment and buildings from it, is a subject I
have studied in some detail and while I could never claim 'expert' status, I
think I know enough to be able to point people in the right direction on their
quest for knowledge.
The article you cited was very interesting, using the 'flash brilliance' and
duration to measure the energy output is innovative. There are just that many
areas of the physics of lightning that we don't understand. Have a look, if you
are interested, at the web site for the University of New Mexico and the
'Langmuir Laboratory' in particular. They are world leaders in research in this
area.
Calvin.
G
Gymy Bob
- Jan 1, 1970
- 0
In this totally OCD for alt energy group, why are we wasting this shot of
energy and treating it as a terrorist when it should be our energy friend?
energy and treating it as a terrorist when it should be our energy friend?
P
ptaylor
- Jan 1, 1970
- 0
Gymy said:
Because untill we understand it well enough to do so,we'd be dancing
with death?
I think harnessing lighting would be a great idea,there's probably
enough energy in one bolt to power my house for a year or more.
......I'm off to daydream about giant lightning-catching capacitors.
G
Gymy Bob
- Jan 1, 1970
- 0
There is **NOT*** enough energy in a lightning bolt to power your house for
more than an hour...if that.
Do the math.
The figures escape me but let's say it puts out a roughly MWatt of power for
100 nanoseconds?
100 x 10^-9 x 1 x 10^6 / 3600 (sec/hr) = 0.0027 wH
oooops.... Wouldn't light your home for a 1/2 second.
OK..OK.. multiply the figures time 100 or 1000. Now it would light a 100W
bulb for 1 second.
more than an hour...if that.
Do the math.
The figures escape me but let's say it puts out a roughly MWatt of power for
100 nanoseconds?
100 x 10^-9 x 1 x 10^6 / 3600 (sec/hr) = 0.0027 wH
oooops.... Wouldn't light your home for a 1/2 second.
OK..OK.. multiply the figures time 100 or 1000. Now it would light a 100W
bulb for 1 second.
M
m II
- Jan 1, 1970
- 0
The evil top poster, Gymy Bob wrote:
Amazing how the rest of the world disagrees with you on this too.
==========================================
Thus, even if all the energy associated with a bolt
of lightning could be captured and used, it would
keep my house going for somewhere between half a
month and five and a half months .
http://www.weatherwise.org/qr/qry.lightningpower.html
==========================================
# A lightning charge contains 30 million volts at 100,000 amperes.
http://www.space.com/scienceastronomy/lightning_backgrounder.html
==========================================
lots more sites. A quick look will tell you all you need to know.
mike
Amazing how the rest of the world disagrees with you on this too.
==========================================
Thus, even if all the energy associated with a bolt
of lightning could be captured and used, it would
keep my house going for somewhere between half a
month and five and a half months .
http://www.weatherwise.org/qr/qry.lightningpower.html
==========================================
# A lightning charge contains 30 million volts at 100,000 amperes.
http://www.space.com/scienceastronomy/lightning_backgrounder.html
==========================================
lots more sites. A quick look will tell you all you need to know.
mike
W
w_tom
- Jan 1, 1970
- 0
Gymy Bob properly answered a question about protecting
photovoltaic systems. Someone posted a silly reply asking
what are holes.
Now Gymy Bob posts an accurate post about so little energy
in lightning. Those who just know lightning must be high
energy they have misread their own citations - ignoring some
key facts.
Lets look at his ridiculous answer. How many volts at
100,000 amps? Nonsense. Where is all that voltage? Up in
the sky. Only a tiny part of lightning's voltage appears at
the ground for use. Even those citations make it obvious.
IOW a world of junk scientists disagree with Gymy Bob. But
those who live in the world of reality see things quite
differently.
Another who also agrees with Gymy Bob posted numbers:
Don Kelly in newsgroup sci.physics.electromag on 4 Nov 2000
entitled "Oddball question":
Don Keely assumed highest numbers of thunderstorms per
year. So where is all this energy? Miniscule. There is
*NOT* enough energy in a lightning bolt.
Both Calvin and Gymy Bob have properly answered the original
poster's question. But half truth and deceptive replies are
from m II. A quick look will tell you all you need to know.
photovoltaic systems. Someone posted a silly reply asking
what are holes.
Now Gymy Bob posts an accurate post about so little energy
in lightning. Those who just know lightning must be high
energy they have misread their own citations - ignoring some
key facts.
Lets look at his ridiculous answer. How many volts at
100,000 amps? Nonsense. Where is all that voltage? Up in
the sky. Only a tiny part of lightning's voltage appears at
the ground for use. Even those citations make it obvious.
IOW a world of junk scientists disagree with Gymy Bob. But
those who live in the world of reality see things quite
differently.
Another who also agrees with Gymy Bob posted numbers:
Don Kelly in newsgroup sci.physics.electromag on 4 Nov 2000
entitled "Oddball question":
Don Keely assumed highest numbers of thunderstorms per
year. So where is all this energy? Miniscule. There is
*NOT* enough energy in a lightning bolt.
Both Calvin and Gymy Bob have properly answered the original
poster's question. But half truth and deceptive replies are
from m II. A quick look will tell you all you need to know.
M
m II
- Jan 1, 1970
- 0
w_tom said:
Another top poster? What a coincidence.
What's 'Gymy' paying you, tom? I sure wouldn't act so irrational for
nothing. He even said he NO numbers and was pulling information out of
thin air (so to speak).
Please do some reading before you post another ill considered reply.
==================================
http://van.hep.uiuc.edu/van/qa/section/Electricity_and_Magnets/Stuff_that_Sparks/20011108073726.htm
OR
http://snipurl.com/bkrg
http://science.howstuffworks.com/framed.htm?parent=lightning.htm&url=http://www.lightningsafety.com/
OR
http://snipurl.com/bkrn
http://www.answerbag.com/q_view.php/8915
http://www.verbund.at/en/media/tips/20040517_blitze_e.htm
http://bbs.trailersailor.com/forums/articles/index.cgi/noframes/read/24
and DOZENS of other sites.
mike
W
w_tom
- Jan 1, 1970
- 0
Not only are bottom posters intolerant and post to make
reading difficult. He must insult other posters because he
posts without technical facts - again. This post has only
one purpose. To remind lurkers which posts provide useful
facts and which poster should be ignored. Amazing how one
bottom posters would claim superiority only because he is so
intolerant as to even complain about posts made easier to
read. It goes right to the credibility of that 'only my way
is correct' poster.
Lurkers are advised to trust Calvin and Gymy Bob; strongly
advised to give no credence to m II. Insults are what a
dirty politician uses to claim technical knowledge he never
learned. Its a propaganda trick often used by technical
shysters. m II provides no technical facts nor demonstrates
any comprehension of the numbers. He cites URLs that actually
contradict his myths. Would he be surprised to learn that
one of his URLs was written by me? How would that be for
exposing his naivity. Apparently he does not read nor
compreshend his cited URLs. He just bottom posts hoping no
one will bother with his 'hard to read' (hidden at the bottom)
text.
Gymy Bob posts accurately both times.
reading difficult. He must insult other posters because he
posts without technical facts - again. This post has only
one purpose. To remind lurkers which posts provide useful
facts and which poster should be ignored. Amazing how one
bottom posters would claim superiority only because he is so
intolerant as to even complain about posts made easier to
read. It goes right to the credibility of that 'only my way
is correct' poster.
Lurkers are advised to trust Calvin and Gymy Bob; strongly
advised to give no credence to m II. Insults are what a
dirty politician uses to claim technical knowledge he never
learned. Its a propaganda trick often used by technical
shysters. m II provides no technical facts nor demonstrates
any comprehension of the numbers. He cites URLs that actually
contradict his myths. Would he be surprised to learn that
one of his URLs was written by me? How would that be for
exposing his naivity. Apparently he does not read nor
compreshend his cited URLs. He just bottom posts hoping no
one will bother with his 'hard to read' (hidden at the bottom)
text.
Gymy Bob posts accurately both times.
M
m II
- Jan 1, 1970
- 0
w_tom wrote:
Insignificant ramblings which were snipped.
Look, I'll make it easy for you. Your hero says that a lightning bolt
will light a hundred watt lightbulb for one second. I say he's very
sadly mistaken in his estimation.
Proof:
We KNOW the energy needed to light this light bulb.
Now, look at any tree that's been split by a lightning strike..such as
THESE.
http://www.percussionadvocates.com/chad/blog/nature/weather/critturStrike1.jpg
http://homepage.ntlworld.com/richard.barker4/archive/index/anglesey1.jpg
http://www.thermojetstove.com/natur...-Juniper Tree Split in Three by Lightning.htm
You are claiming that a lightning strike with the energy to light ONE
lightbulb for ONE second has enough energy to THIS sort of damage.
I fear you AND your hero are delusional and with that I'm ending this
little exchange. I fear no one will get anywhere with you.
mike
Insignificant ramblings which were snipped.
Look, I'll make it easy for you. Your hero says that a lightning bolt
will light a hundred watt lightbulb for one second. I say he's very
sadly mistaken in his estimation.
Proof:
We KNOW the energy needed to light this light bulb.
Now, look at any tree that's been split by a lightning strike..such as
THESE.
http://www.percussionadvocates.com/chad/blog/nature/weather/critturStrike1.jpg
http://homepage.ntlworld.com/richard.barker4/archive/index/anglesey1.jpg
http://www.thermojetstove.com/natur...-Juniper Tree Split in Three by Lightning.htm
You are claiming that a lightning strike with the energy to light ONE
lightbulb for ONE second has enough energy to THIS sort of damage.
I fear you AND your hero are delusional and with that I'm ending this
little exchange. I fear no one will get anywhere with you.
mike
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