Leonard Caillouet wrote:
> "w_tom" <w_tom1@usa.net> wrote in message
> news:82da8b44-e386-4911-94c0-99b0671599ee@24g2000hsh.googlegroups.com...
>> People who are more than TV repairmen learn from their mistakes and
>> correct reasons for that failure. TV repairmen only fix defects -
>> never bother to learn how those failures can be avoided. Let's have
>> some fun. Let's reply using the same mockery and insult that Michael
>> uses. Except this post will be accurate about Michaels intelligence.
>
> I am merely a TV repairman who happens to have quite a bit of education,
> and has done much research on the matter. We began installing good
> basic MOV based suppression on our clients' systems long ago, using
> system level units that protect all incoming lines. We also pay close
> attention to proper grounding. What we have found over many years of
> this practice in one of the most lightning intense areas of the USA, is
> that our systems never take damage. During times of high thunderstorm
> activity, however, we see several times the repair volume, and
> invariably, the user did not use a surge suppressor. Our clients are
> happy with the systems that we sell and with the reliability. There are
> good reasons to suspect that system level surge suppressors do work, but
> grounding cannot be ignored.
>
> As for you w_tom, you have done far more to clutter groups than to
> provide any useful information. While your emphasis on grounding is
> good advice, much of the rest of your arguments are out of context and
> misleading. Michael may be a crochety *** sometimes, but at least he
> consistently provides useful information. Stick to preaching the
> importance of grounding and give the rest a break.
>
> Leonard
Thank you, Leonard, for a breath of fresh air in this onerous thread
that w_tom perpetuates ad infinitum. This isn't his first, for newbies
trying to fathom his morass.
I've been a TV repairman. I'm now a "communications electrician" which
means I deal with telephone lines/switches, land-mobile radio, microwave
radio systems, security systems, and the like; in high-voltage
switchyards and substations. We deal with huge surges from switching
transients and direct lightning hits on the transmission lines. I know
first-hand what happens when surges hit. When I said "transmission
lines", I'm talking both from the 60hz side as well as the RF side as
the lengths are sufficient to act that way.
Define "ground" or "earth", Mr w_tom. Have you ever run an ANSI spec
ohms test on one? I think not. I've done grounding for military tactical
radio systems and complete commo systems. What you think is "ground" may
not be ground at all due to soil composition. I've seen ground rod
"farms" made up of 20+ vertical 8' rods on a 10 foot grid come up in the
500 kilohms range when the same rods in the same location would test
lower than 1000 ohms if those same stakes were buried sideways 18" below
surface.
Substations/switchyards have "ground mats" of heavy copper wire in a
grid spacing of 1-2 feet and about 6 feet under everything that's
covered with gravel. It's also cad-welded at all intersections to
prevent corrosion. This ground mat system is also used at well-designed
radio sites. Even with this elaborate grounding system, a major
malfunction at 230KV can create such a voltage differential to induce
fatal "step voltage" between your legs. http://ballengearry.com.au/papers/St...004_090804.pdf
For 120Vac grounding on our equipment, we try our best to bring all
equipment grounds (racks and cable trays as well) to a single point that
*then* connects to the building's ground as close as possible. We do
have the advantage of most equipment running off DC at 24, 48, or 130
Vdc on huge battery racks that can absorb a lot of surge energy.....
In alt.engineering.electrical bud-- <remove.budnews@isp.com> wrote:
| phil-news-nospam@ipal.net wrote:
|> In alt.tv.tech.hdtv bud-- <remove.budnews@isp.com> wrote:
|>
|> | Previously you said Martzloff "flubbed the experiment".
|>
|> I remember that. You were telling me about some information he had
|> obtained from some experiment.
|>
|> | Now you agree with Martzloff that branch circuit must be 200m for
|> | transmission line behavior with 1.2 microsecond rise time.
|>
|> That's not a result of an experiment.
|
| "*From this first test*, we can draw the conclusion (predictable, but
| too often not recognized in qualitative discussions of reflections in
| wiring systems) that it is not appropriate to apply classical
| transmission line concepts to wiring systems if ..."
|
| As usual, you don?t know what was written.
What what kind of surge did Martzloff use to carry out that test?
|> I'm not so sure the exact distance
|> is 200m for that exact rise time. But that is a subjective thing.
|
| Quit equivocating. Where is your cite. Like for nanosecond risetimes.
Observation.
|> | You say that doesn't apply because surges are faster. Martzloff uses 1.2
|> | us because that is a standard rise time for surges produced by lightning
|> | as defined in IEEE standards.
|>
|> Martzloff did not say that was a defined standard in the statement you
|> quoted. He just used it as an example to come up with the 200m figure.
|
| He used it because 1.2/50 (voltage) is an IEEE standard. The 8us from
| w_?s engineer is another standard (8/20 current).
The standard for what? The typical surge?
|> | w_' professional engineer source says 8 micoseconds with most of the
|> | spectrum under 100kHz.
|>
|> Even with 1 nanosecond rise time, most of the energy will be present in
|> the spectrum below 100 kHz. That means nothing when the surge is strong
|> enough to have energy above some frequency that is relevant to the whole
|> system involved that can do damage. That frequency might be 100 Mhz for
|> some thing, and 1 GHz for other things.
|
| Still missing ? your source. Nanosecond risetime. 100MHz spectrum.
Observation. Of course this is a concept you cannot understand.
|> | You still have *no sources that support your belief* that risetimes are
|> | far faster.
|>
|> I have experience and observation for that. I need no more.
|
| Lots of people have experience and observation with flying saucers.
|
| The rest of us want a source.
The only flying saucers I have seen are the ones I've tossed.
--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
| Google Groups. If you want your postings to be seen by more readers |
| you will need to find a different place to post on Usenet. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |
> phil-news-nospam@ipal.net wrote:
>
>> In alt.tv.tech.hdtv bud-- <remove.budnews@isp.com> wrote:
>>
>> | The last standards for simulating typical surge waveforms I have
>> seen | (IEEE) were
>> | 1.2 us rise time, 50 us duration
>> | 8 us rise time, 20 us duration
>> | a ring wave with a frequency about 100kHz.
>>
>> So now you are saying these figures represent a typical surge waveform,
>> as opposed to the worst case waveform you said a long time ago.
>
>
> Still missing - your source that indicates nanosecond rise times and
> 100MHz spectrum.
>
>>
>> What does the "/" mean in that case, anyway? I never got to ask you that
>> before. Does it mean "divide 1.2 by 50"?
>
>
> It is standard notation in the surge field. 1.2 us risetime and 50 us
> duration
>
Sloppy notation.
In article <fvo6qr11f4i@enews1.newsguy.com>, Boden@tidewater.net
says...
> bud-- wrote:
>
> > phil-news-nospam@ipal.net wrote:
> >
> >> In alt.tv.tech.hdtv bud-- <remove.budnews@isp.com> wrote:
> >>
> >> | The last standards for simulating typical surge waveforms I have
> >> seen | (IEEE) were
> >> | 1.2 us rise time, 50 us duration
> >> | 8 us rise time, 20 us duration
> >> | a ring wave with a frequency about 100kHz.
> >>
> >> So now you are saying these figures represent a typical surge waveform,
> >> as opposed to the worst case waveform you said a long time ago.
> >
> >
> > Still missing - your source that indicates nanosecond rise times and
> > 100MHz spectrum.
> >
> >>
> >> What does the "/" mean in that case, anyway? I never got to ask you that
> >> before. Does it mean "divide 1.2 by 50"?
> >
> >
> > It is standard notation in the surge field. 1.2 us risetime and 50 us
> > duration
> >
> Sloppy notation.
On Mon, 5 May 2008 19:19:16 +0100, Mike Tomlinson <mike@jasper.org.uk>
wrote:
>but their
>effectiveness when used on ungrounded outlets is reduced, since the path
>to ground doesn't exist.
I was going to ask whether this would help protect delicate components
in any way, but of course, the neutral is earthed nearby anyways, and
the third earth wire is just a backstop?
In article <ercv14losi2mbapd8k5bmirr77vffj6mkn@4ax.com>, spamfree@spam.heaven writes
>I was going to ask whether this would help protect delicate components
>in any way,
Yes, as the surge protector is working to some extent, but it would work
far more effectively if it were plugged into a grounded outlet.
There's also the problem that using a surge protector in an ungrounded
outlet will cause the earth on the protector to rise in potential while
the protector is conducting a surge. Depending on the equipment plugged
into that strip, this has the potential to cause damage, as well as an
electrical shock to anyone touching a metal-cased appliance with a 3-pin
lead plugged into the strip.
Thus surge protectors should only be plugged into grounded outlets.
There will usually be a warning on the protector itself or in the user
instructions stating this.
> but of course, the neutral is earthed nearby anyways, and
>the third earth wire is just a backstop?
No. The earth pin, although bonded to neutral at the consumer unit
(=breaker box in US) should be regarded as a separate, third connection
from then on. The neutral is there to carry return current; the earth
is there for safety.
----------------------------
"bud--" <remove.budnews@isp.com> wrote in message
news:e234c$481f53e8$4213eabe$21042@DIALUPUSA.NET.. .
> Don Kelly wrote:
>> ----------------------------
>> "Tony Hwang" <dragon40@shaw.ca> wrote in message
>> news:dncTj.112858$rd2.31639@pd7urf3no...
>>> phil-news-nospam@ipal.net wrote:
>>>> In alt.tv.tech.hdtv Michael A. Terrell <mike.terrell@earthlink.net>
>>>> wrote:
>>>>
>>>> | Bull****. Like ALL charges, it simply seeks a complete circuit to
>>>> | flow. You have absolutely no grasp of the basic concepts, yet you
>>>> | continue to spout your ignorance and lies.
>>>>
>>>> Not true.
>>>>
>>>> When you close a switch between a power source and a pair of wires that
>>>> go
>>>> out yonder, the electrical energy does not "know" whether the circuit
>>>> is
>>>> complete or not. If it refused to flow, it would not be able to find
>>>> out.
>>>> It will flow, whether the circuit is complete or not. What happens
>>>> after
>>>> that depends on what is at the other end, which could be an open
>>>> condition,
>>>> a short circuit, or some kind of resistive or reactive load.
>>>>
>>>> You've claimed to have worked in broadcasting in an engineering role.
>>>> So
>>>> you should understand what happens at the end of an open transmission
>>>> line.
>>>> The electricity flows to get to the open end. Yet it is not a
>>>> "complete
>>>> circuit".
>>>>
>>> Hmmm,
>>> You seem to be confused between current flow(energy) and
>>> voltage(poential) Nothing flows in an open circuit. If not we have to
>>> rewrite Ohm's law. Show your credential to make a stamement like that.
>>> Shameful.
>> ------------------------
>> Actually, you are showing some confusion. Phil is right in that he is
>> bringing out a point that normal lumped RLC circuit theory doesn't handle
>> because it essentially treats the speed of propagation of electrical
>> signals as if it were infinite- which isn't true.
>> .
>> 2)Also, on energizing a line whether it is open or closed, there is a
>> current flow as the applied voltage "sees" the characteristic impedance
>> of the line (wire or whatever) so a current will flow-even on an open
>> circuit- until there is a modifying reflection from the termination. For
>> a house the distances are such that this may be of the order of 0.1-0.2
>> microsecond. After all such reflections at terminations have ceased or
>> are negligable, conventional circuit theory is applicable.
>> In these situations, you are dealing with wave propagation rather than
>> conventional circuit theory.
>> This is the regime that is of interest in considering "surge protectors"
>
> The last standards for simulating typical surge waveforms I have seen
> (IEEE) were
> 1.2 us rise time, 50 us duration
> 8 us rise time, 20 us duration
> a ring wave with a frequency about 100kHz.
>
> All are long relative to 0.2 microsecond, so wave propagation should not
> be relevant for household circuits.
----------------------------------------
Your point is true- the time interval is so small that for practical
purposes it can be ignored. I am not denying that. Obviously I gave that
impression- sorry for that.
I was simply pointing out that phil had it right in theory and Tony had it
wrong.
After this time for the wave to travel to the end and be reflected (and
other re-reflections die out) then conventional circuit theory is
applicable. The fact that the time is extremely small simply means that we
can pretend that it doesn't even exist.
While Matzloff is right in the time for a round trip is of the order of
200m, it is also dangerous to assume that one can ignore waves for shorter
distances. For example, a stroke to a tower of an EHV line (a lot less than
200m) will go down the tower, meet ground resistance and be reflected.
Such reflections have been found to be more likely to cause flashover than
direct strokes to the line (EPRI). Similarly, the practice in substations
is not "whole station" protection (where this is applicable, it must be done
considering a number of factors- quite interesting ) and putting specific
protection as near as possible to the protected apparatus-definitely within,
say, 10m. - It's not just the time to peak that is the critical factor. Do a
lattice diagram approach or use Bergeron's method (Hermann Dommel did a lot
of work with this at EPRI and has a lot of papers in IEEE- more dealing with
switching surges than lightning).
It's been a long time since I did any calculations in this area so I would
have to brush up.
Now - is this all germane to household protection? You say not and I agree
with you- because household equipment can ride through - at worst- doubling
of the clamped voltage for a very short time even though the clamped voltage
is relatively small compared to the peak of the incoming surge. --
>
> A favorite article from w_ also uses a "8x20 us impulse as a very rough
> representative pulse" with most harmonic content from 20kHz to 100kHz.
>
> Martzloff, using the shorter rise time, has written: "For a 1.2/50 us
> impulse, this means that the line must be at least 200 m long before one
> can think in terms of classical transmission line behavior."
>
> What reason is there to believe wave propagation is relevant to house
> circuits?
>
>>
>> As to the advantage of "whole house" vs local surge protection, "whole
>> house protection depends on distances to all "protected" items being
>> small.
>
> Longer distances make the system more subject to effects like direct
> induction from lightning into the wiring. I don't see why, in general,
> the distance has to be small.
>
>
> --
> bud--
On May 5, 1:05 pm, spamf...@spam.heaven wrote:
> I'm curous to know how surge suppression can work without a ground
> (earth) of any sort. Does the "black box" detect overvoltage and
> disconnect the power like an earth leakage safety switch?
>
> This might be fine for a TV, but surely not for a computer.
>
> I don't recall any computer I've owned that did not have a three wire
> connection to the mains. That and a MOV is OK for smallish surges, but
> I believe that for a large surge, the sort that will blow a telephone
> off the wall, one needs a large, short-path earth for the surge
> detector to dump the extra power down.
>
> I've got a few plug in protectors here and there to sop up a small
> spike, but when a storm is within a few km, I pull the phone wire out
> of the ADSL router, and the plug out of the mains. If I'm working at
> the time, I might just keep a watch on the weather radar and count
> lightning fashes to thunder times. It's rare that I get interrupted. I
> have underground power and phone lines so that gives a little extra
> protection, I believe.
This will address some of your questions only in summary. Details
are provided in other posts.
First, much of this stuff was learned by earliest 20th century
hams. They would disconnect their antenna, put the lead inside a
mason jar, and still suffer radio damage. Even mason jars could not
stop or block lightning. But then the antenna was earthed, then damage
stopped. It's just like Franklin's lightning rod (air terminal).
Protection has always been about diverting "it to ground, where it can
do no harm". Disconnecting did not provide sufficient protection.
That wire had to be earthed.
Protection for the TV, computer, and all other appliances is same.
Computers contain some of the most robust protection. Computer grade
UPSes can output electricity so dirty (when in battery backup mode) as
to even harm some small electric motors. But computers are so robust
as to make even that 'dirty' electricity irrelevant. Do not assume
computers have less internal protection. Intel ATX standards require
computers to be more robust than what is standard for other
appliances.
No protection exists by disconnecting - the black box. Air is a
best insulator. Lightning travels through 3 miles of air to contact
earth. What magic black box do you own that can stop what three miles
of sky could not? Protectors do not stop, block, or disconnect from
lightning. Furthermore, a lightning surge does damage too fast. A
fastest disconnect relay takes milliseconds. Lightning surges do
damage in microseconds. Two of so many reasons why protection is not
achieved by disconnecting.
Try damming a river to stop a flood. Dam gets swept away. Move
that dam off to the side; call it a dike. Open a large channel
downriver. Protecting by disconnecting, blocking, or absorbing surges
is akin to that dam - useless. Instead, install (and earth) a 'whole
house' protector - akin to a large channel downriver. And then
install dikes - internal protection inside appliances or other
supplementary protection.
Even dikes (supplementary protectors) are useless without that large
channel downriver - the properly earthed 'whole house' protector.
Routine is for direct lightning strikes to be earthed by a 'whole
house' protector. Routine is for a properly sized protector to earth
surges AND remain functional. A protector damaged by a direct
lightning strike - grossly undersized - is designed in direct
violation of MOV manufacturer's specs. MOV manufacturers are quite
clear about this. MOVs must only fail by degrading; not fail by
vaporizing. MOVs also do not work by sopping up surge energy. But
grossly undersizing a plug-in protector and a resulting explosive
damage gets the naive to recommend an obscenely overpriced protector.
Yes, grossly undersizing a protector can get the naive to recommend
more ineffective protectors.
An effective protector earths direct lightning strikes AND remains
functional. An effective protector means nobody knew the surge even
existed. But no explosive failure means some here would not recommend
that protector.
Above described secondary protection. Homeowners should also
inspect their primary inspection system: http://www.tvtower.com/fpl.html
Buried wires do not provide effective protection. An industry
professional provides this application note. Notice even underground
wires must be earthed before entering the building. Even underground
wires can carry surges, destructively into the building. Any wire
that enters the building - overhead or underground - must connect to a
single point earth ground either directly (ie cable TV, satellite
dish) or via a protector (ie telephone, AC electric). The app note
shows two structures. Any wire into either structure first connects
to that structure's single point earth ground: http://www.erico.com/public/library/...es/tncr002.pdf
And finally, it is posted multiple times including a reference to an
article for EE entitled "Protecting Electrical Devices from Lightning
Transients". That safety ground and neutral wire cannot provide
earthing for a long list of reasons.
Nobody described how much more earthing is installed in switching
centers (COs), electric substations, etc just to obtain a little
better earthing. A ten foot earth ground rod can be a massive
earthing improvement for surge protection. And then high reliability
facilities may spend $thousands more just to make that earthing but a
little better. Why so much extra conductors and labor for just a
little better ground? Because every little better earthing means that
much more surge protection. What makes a protector even more
effective? Better earthing.
So yes, where surge damage is not acceptable, then facilities will
do that much more work just to get a little better earthing. Earthing
is critical for direct lightning strikes without failure. Does that
mean a homeowner without a massive earthing mat should do nothing? Of
course not. Locating 3 meter ground rods (per post 1990 NEC
requirements) less than 10 feet from breaker box and telco provided
surge protector means significantly better protection. Anyone
building a new home should plan their surge protection where footings
are poured - see nobody's reference to cadwelding. Footings with
appropriately installed conductors (rebar) provide a home with
significant improvement (Ufer grounds). Protection should be planned
when the footings are poured. Better earthing (surge protection) for
so little money.
Nobody also discusses single point earth ground that is essential
for surge protection. Why? Again, a protector is only as effective
as its earth ground. Single point earth ground is essential to an
effective protector.
Some homeowners don't have that single point option due to failures
by the builder. One utility describes how to fix that defective
earthing: http://www.cinergy.com/surge/ttip08.htm
Why do serious facilities do so much for their earthing system?
Earthing provides surge protection - where surge energy must be
harmlessly dissipated. And then, as Nobody notes, sometimes that
earthing system gets compromised by geology we did not know about.
What happens if damage occurs? We return to locate an earthing
defect. Even a nearby pipeline may adversely affect that earthing
system. If damage results, then discover a defect in the earthing
system. As Nobody demonstrates, so much labor to make earthing even
better because a surge protector is only as effective as that earth
ground.
BTW, battery racks do not absorb surge energy. Another concept even
taught in basic circuit theory - superposition. To surges, that
battery rack is equivalent to a short circuit. Batteries do not
absorb energy (if ignoring a battery's internal resistance). Those
batteries essentially connect surge currents to wires on both sides of
those batteries. To a surge, batteries are electrically equivalent to
a wire. Batteries are typically well earthed - meaning those
batteries will act just like a shunt mode surge protector - connecting
surge energy into earth. Batteries don't work as surge absorbers.
Batteries connect (shunt, divert, clamp) surge energy into earth.
On May 5, 6:31 pm, "nobody >" <usenetharves...@aol.com> wrote:
> I've been a TV repairman. I'm now a "communications electrician" which
> means I deal with telephone lines/switches, land-mobile radio, microwave
> radio systems, security systems, and the like; in high-voltage
> switchyards and substations. We deal with huge surges from switching
> transients and direct lightning hits on the transmission lines. I know
> first-hand what happens when surges hit. When I said "transmission
> lines", I'm talking both from the 60hz side as well as the RF side as
> the lengths are sufficient to act that way.
>
> Define "ground" or "earth", Mr w_tom. Have you ever run an ANSI spec
> ohms test on one? I think not. I've done grounding for military tactical
> radio systems and complete commo systems. What you think is "ground" may
> not be ground at all due to soil composition. I've seen ground rod
> "farms" made up of 20+ vertical 8' rods on a 10 foot grid come up in the
> 500 kilohms range when the same rods in the same location would test
> lower than 1000 ohms if those same stakes were buried sideways 18" below
> surface.
>
> Substations/switchyards have "ground mats" of heavy copper wire in a
> grid spacing of 1-2 feet and about 6 feet under everything that's
> covered with gravel. It's also cad-welded at all intersections to
> prevent corrosion. This ground mat system is also used at well-designed
> radio sites. Even with this elaborate grounding system, a major
> malfunction at 230KV can create such a voltage differential to induce
> fatal "step voltage" between your legs.
>.http://ballengearry.com.au/papers/St...e_update_for_2...
>
> For 120Vac grounding on our equipment, we try our best to bring all
> equipment grounds (racks and cable trays as well) to a single point that
> *then* connects to the building's ground as close as possible. We do
> have the advantage of most equipment running off DC at 24, 48, or 130
> Vdc on huge battery racks that can absorb a lot of surge energy...
On May 5, 2:35 pm, bud-- <remove.budn...@isp.com> wrote:
> The IEEE guide is aimed at "electricians, architects, technicians, and
> electrical engineers who were not protection specialists."
IEEE and NIST state fundamental facts. Industry standard facts and
embarrassing questions.that Bud will ignore to lie and to promote plug-
in protector sales:
1) How does that plug-in protector provide protection without the
'always necessary' earth ground? What does a protector do? Bud
provides only two citations. Both disagree with his claims. The NIST
bluntly defines what a protector must do - Page 6:
> You cannot really suppress a surge altogether, nor
> "arrest" it. What these protective devices do is
> neither suppress nor arrest a surge, but simply
> divert it to ground, where it can do no harm.
Bud says his plug-in protectors somehow suppress or arrest surges.
Somehow, 'clamping to nothing' means that surge energy disappears?
Somehow protectors can work without earthing? NIST citation further
contradicts Bud on Page 17:
> A very important point to keep in mind is that your
> surge protector will work by diverting the surges to
> ground. The best surge protection in the world can
> be useless if grounding is not done properly.
2) Bud not only denies this also so important single point earth
ground. He also ignores what happens when a protector is too far from
earth and too close to appliances. Page 42 Figure 8: the surge
earthed 8000 volts destructively through appliances. This is the
second point from his citations that Bud must ignore.
3) So if a plug-in protector is effective protection, then
manufacturer specs will list each type of surge and protection from
that surge. Bud never provides that spec either. Why? Plug-in
protectors don't claim to protect from the type of surge that
typically causes damage. Not one plug-in protector manufacturer will
claim that protection - made obvious because Bud will not post those
specs and ignored over 400 requests for those specs.
4) No earth ground means no effective protection. A protector is
only as effective as its earth ground. Another reality that Bud must
ignore to post incessantly.
None of this is new. It is again posted because Bud continuously
ignores that even his own citations contradict him. Meanwhile w_tom
has provided many tens of professional citations that also contradict
Bud; that define how effective protection is routinely installed where
direct lightning strikes must not cause damage. We install effective
protection for lightning so that all other (and lesser) surges are
also made irrelevant. Surge protection is so routine for the past 100
years as to be traceable to human failure. Even the protector must
remain functional after a surge.
Re: Surge / Ground / Lightning 
Linear Mode
