Surge / Ground / Lightning

[w_tom]

I can attest to vhf/uhf content in lightning strikes. I worked for a
communications outfit. We owned and maintained a number of comm sites
with towers and antennas. One strike on an antenna destroyed the LDF rf
cable all the way to the polyphaser at the bottom of the tower.

Eric notes damage only up to the earthed Polyphaser protector.
Polyphaser is legendary among professionals who install effective
protection. Polyphaser is blunt about what provides protection - why
their products are so effective. Polyphaser protectors are earthed.
Polyphaser application notes repeatedly discuss what their products
must connect to; what provides protection: earth ground:
http://www.polyphaser.com/technical_notes.aspx

 

[Mike Tomlinson]

[snip w_'s usual lies and bald statements with no citations or proof to
back them up and his boilerplate messianic statement of religious
belief]

Same technique used by Rush Limbaugh to prove Saddam
had WMDs.

ROTFL!! You've really lost it this time, w_twat.
I hereby invoke Godwin's law.

 

[trader4]

[snip w_'s usual lies and bald statements with no citations or proof to
back them up and his boilerplate messianic statement of religious
belief]

Same technique used by Rush Limbaugh to prove Saddam
had WMDs.

ROTFL!!  You've really lost it this time, w_twat.  
I hereby invoke Godwin's law.

And as usual, W_'s statement taken at face value is wrong and/or
misleading. A simple check of history shows Saddam did in fact have
WMDs for years, because they were used in war and against his own
people. The UN weapons inspectors had spent a decade of hide and seek
locating and destroying most of them. Just prior to the start of
the Iraq war, not only did US intelligence believe he still had some
of them and was trying to reconstruct the weapons programs, but so did
British, Israeli and Russian intelligence.

 

[Guest]

What will provide sufficient earthing?

A large series air-core copper toroid (eg 1' diam x 2' long with
a 3" wire spacing) followed by a small spark gap to a poor ground.

Nick

 

[trader4]

   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.

I'd love to see a reference for this. In that time frame, lightning
was already fairly well understood. I find it hard to believe any ham
would try to use a mason jar in this way. Sounds more like some urban
legend to me.



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.

And guess what component is used as part of that robust protection?
MOVs, which W_ denies are used in electronics/appliances. Once again,
I'll ask the same question W_ refuses to answer. How is it that MOVs
or any other component can offer protection when used in a PC power
supply, but are useless in a plug-in surge protector? According to
W_, surge protection is impossible unless there is a direct and short
connection to earth ground. Does the PC power supply come with a
built-in earth ground?

 

[Guest]

(e-mail address removed) wrote:

| I wonder if "ring mains" (an extra wire from the last outlet to make
| a loop back to the fusebox) are legal in the US. Seems like a nice way
| to improve voltage regulation with a little extra wire, and if the ring
| wire only breaks in one place, all the outlets keep working.

It is not legal in the US. It is also considered technically unsafe.

Lots of things are "technically unsafe" Safety is often used as excuse
for people-control...

The safest case would be wiring both ends of the ring into the same breaker
rated for the current capacity of the wire as if used in a regular branch
circuit.

Sounds good to me.

... If the wire became loose at one point in the ring, it would still be
a potential hot spot

Maybe not too hot, if the rest of the wire is intact.

... a neutral would have to be wired in from both ends of the ring, and
each be wired in a separate hole (not doubled up) in the neutral bus bar.

The "separate hole problem" has lots of solutions.

... The issue of voltage stability is addressed by keeping branch circuits
short. It is my understanding that UK ring circuits tend to be longer and
run all around the portion of a house (often an entire floor).

Sounds more cost-effective to me. Why don't more people use large PEX pipe
"ring mains" with Ts, vs home runs with tiny pipe and expensive manifolds?

Nick

 

[trader4]

  Using trader's reasoning, all appliances contain MOVs.  Therefore
plug-in protectors need not be purchased AND all appliances never
suffer surge damage. Conclusions directly from trader's post.

LOL. You're a real riot. YOU are the one that in previous and
similar long threads has stated that manufacturers of appliances and
electronic equipment put surge protection in them and that it works,
and used that as an argument as to why a plug-in surge protector is
useless.

I never stated that all appliances contain MOVs. I only stated that
they frequently or commonly do. You, on the other hand, denied that
MOVs are used in that kind of application. At which point, I
provided you references to a couple of articles in Appliance Magazine
that discuss how MOV are in fact commonly used in those applications:
A poster just told you his microwave has them. Another told you the
phone system sitting in front of him has them.

So, once again, stop lying about what I stated and answer the simple
question:

How is it that MOVs can work as surge protection inside the appliance,
but not in a plug-in surge protector? Where is that essential direct
earth ground? Does that microwave come with a built-in earth
ground? If not, then just like the plug-in surge protector, there is
no direct earth ground, so how can the MOV be helping protect the
microwave?

And it would help if you just answer that question, not start with a
long rant.

 

[trader4]

| 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. --

What if the surge is an extreme case (e.g. direct strike very near) and itis
arriving at protection devices in common mode (same polarity on all three
wires).  Bud's assertion _seems_ to be that no surge could ever be of the
type with substantial energy at high frequencies.  My belief is that they
can, and will at times.  Lightning strokes have that energy, or else you
would not receive them on UHF.  If the stroke is strong _and_ close (e.g..
less line inductance between the point of strike and where it is being
considered), then more of that UHF energy will arrive.

I have seen damage patterns in electronics that strongly suggests that there
were specific paths involved based on minor levels of reactance in the circuit.
A resistor would be melted along one path, but not so along another which had
a small inductor (3 turns in air) in the way.  And this device (a VCR) was on
a surge protector along with a TV that was unharmed.

If Bud is just arguing about the _typical_ (median?) surge level, then maybe
we are arguing apples and oranges.  I certainly don't intent to protect against
50% of surges.  My target is better than 99%.  I want to feel comfortable
sleeping through a severe thunderstorm while my computers and media center
remain plugged in.

I do agree that things can survive at the clamping voltage.  But there has to
be a clamping situation.  It's too easy for a surge to come in as a common
mode surge where the voltage difference across the MOVs would be (nearly) zero.
Then all we have is a propogating wavefront.  And if it is strong and/orclose
then we have very fast rise times.  And it passes by the MOVs "laterally".

There's probably a big difference of opinion about just how much protection is
worth it.  But one thing I do see in at least part of this thread is that Bud
focuses on quoting things other people say, and does very little to express
things in his own words.  That suggests he reads but does not fully understand.
And that means I can't ask questions of what is said in the thread.  Since Bud
can't (or won't) defend what he's saying in his own words based on his own
knowledge, it's not really a two way street.  His "experts" are not involved
in the debate; they can neither defend their position nor be questioned about
it to get more details.

I find Bud's use of actual references interesting and think they add
to his credibility. Trying to suggest that someone using references
such as the IEEE to support their position detracts from their
credibility is preposterous. And trying to impugn him in this fashion
only detracts from your credibility.

 

[bud--]

You're quite correct. It's a practice that the GPO (forerunner to
British Telecom) abandoned in the 1960s, showing how up to date w_'s
"knowledge" is.

Phone wires were clamped to ground before the 1960s?

 

[bud--]

I had a microwave oven that had a MOV across the 120V line ahead of the
power switch. The other side of the 120/240 20A circuit supplied a
refrigerator. The loss of the neutral applied a good part of the 240V
across the MOV when the refrigerator attempted to start.

The MOV didn't last long! It would probably have been OK on the load
side of the switch.

Using a MOV to protect against loss of neutral (in the article) is
rather futile. Sustained overvoltage will rapidly kill them. Although if
the protected load was across the MOV and a fuse was ahead of both
protection may work. Would be interesting why the MOV was ahead of the
switch.

I know that refrigerators should be alone on a "home run" circuit, and
neutrals shouldn't be connected with wire nuts, but that wasn't how it was!

My only complaint with some plug-in protectors is that the MOVs are
often much too small. I've also seen some with only a line-line MOV.

I would only buy one with fairly high ratings (which are readily
available).

UL, as far as I know, requires MOVs to be L-N, L-G, N-G. I thought that
was the standard since the start, which w_ said was 1985.

 

[charles]

Phone wires were clamped to ground before the 1960s?

not as such, but phones in rural areas often had an earth terminal on the
household terminal box.

 

[bud--]

| (e-mail address removed) wrote:
|> | (e-mail address removed) wrote:
|>
|> |> | 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.
|
| Observation proves flying saucers and magic.
|
| Without supporting sources it is Phil's Phantasy Physics.
| Where is a source that supports your belief in nanosecond risetimes and
| 100MHz spectrum?

There is no point in spending the effort to find some quotable source because
you wouldn't know what to do with it.

In other words - it is Phil’s Phantasy Physics, so no supporting link
exists.

 

[bud--]

Maybe you should review what you actually stated in the context of
current surge supression discussion:
"
"The MOVs will act like conductors when they are clamping. The surge
will
|> |> take both paths ... the path through the MOVs, and the path
going past the
|> |> MOVs. In general, about 50% will go each way. That can vary at
higher
|> |> frequencies. "

That sure sounds like 50% of the surge is going through the MOV and
the other 50% is going on past it to the protected equipment.

And that I would have to agree with Bud on, it's phantasy physics,
because if it were true, no type of surge protection would work,
because it would only be 50% effective.

He is using transmission line effects which Martzloff investigated and
said do not come into play unless the circuit is 200m long. Phil claims
high frequencies.

Still missing - a source that supports nanosecond risetimes and 100MHz
spectrum.

 

[bud--]

Bud will only challenge the hanford link because he cannot challenge
those 'scary pictures'.

w_ only provides those ‘scary pictures’ because he has no valid
technical arguments.

Still missing - a link to any source that says UL listed plug-in
suppressors made after 1998 are a problem.

Another is a fire marshal describing
why plug-in protectors can create house fires.

The fire marshal said: "More modern surge suppressors are manufactured
with a Thermal Cut Out mounted near, or in contact with, the MOV that is
intended shut the unit down overheating occurs.[sic]"

And then Bud posts a half fact. UL1449 was created on 28 Aug 1985 -
not in 1998 as Bud claims.

It is really hard to understand how someone could be stupid enough to
not know the difference between a creation date and a revision date.

From w_'s hanford link:
"Underwriters Laboratories Standard UL 1449, 2nd Edition, Standard For
Safety For Transient Voltage Surge Suppressors, now requires thermal
protection in power strips. This protection is provided by a thermal
fuse located next to the MOV."

The fire marshal says the same thing (above)

If w_ had any knowledge of the field he would know UL 1449, 2nd Ed was
effective in 1998.

Bud refuses to post a
specification for one simple reason.

Posted often and ignored. Another of w_'s favorite lies.

In reply, this is
what Bud is really promoting - these 'scary pictures':
http://www.hanford.gov/rl/?page=556&parent=554

The lie repeated. But w_ is a fan of Josef Goebbels and thinks if you
repeat a lie often enough, people will believe it.


Still missing - a link to another lunatic that says plug-in suppressors
are NOT effective.

Still missing – answers to embarrassing questions:
- Why do the only 2 examples of surge suppression in the IEEE guide use
plug-in suppressors?
- Why does the NIST guide says plug-in suppressors are "the easiest
solution"?
- Why do all but one of w's "responsible manufacturers" make plug-in
suppressors?
- Why does SquareD say in addition to their "whole house" suppressors
"electronic equipment may need additional protection" from plug-in
suppressors.
- Why aren't airplanes crashing daily when they get hit by lightning (or
do they drag an earthing chain)?

–-
bud--

 

[bud--]

| (e-mail address removed) wrote:
|>
|> | 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. --
|>
|> My belief is that they
|> can, and will at times.
|
| People believe in flying saucers.
| Where is a source that supports your belief?

My observations support my belief.

Observations support belief in astrology, reflexology, homeopathy,
dowsing, healing touch, Feng Shui, Sylvia Brown, ....

|> I do agree that things can survive at the clamping voltage. But there has to
|> be a clamping situation. It's too easy for a surge to come in as a common
|> mode surge where the voltage difference across the MOVs would be (nearly) zero.
|> Then all we have is a propogating wavefront. And if it is strong and/or close
|> then we have very fast rise times. And it passes by the MOVs "laterally".
|
| Where is a source that supports your belief in nanosecond risetimes and
| 100MHz spectrum?

Another poster followed up to my post you just followed up to that also has
experienced the same thing.

I am not interested in direct lightning strikes to my house. Protection
requires lightning rods.

I am interested in surge protection. That is surges coming in on utility
wires, direct induction, ground potential rise, ....

Martzloff says transmission line effects require 200m branch circuits.

You disagree with Martzloff (and have said "he flubbed the experiment")
but provide no sources that agree with your belief.

|> But one thing I do see in at least part of this thread is that Bud
|> focuses on quoting things other people say, and does very little to express
|> things in his own words.
|
| I focus on the real world. You focus on your beliefs.

You focus on citing and quoting things you do not understand well enough to
just talking about them in technical terms.

In other words, it is Phil’s Phantasy Physics.

Where is a source that supports your belief in nanosecond risetimes and
100MHz spectrum?
There should be plenty of sources.

 

[fl_fly_boy]

I think the UL requires only that the MOVs don't start a fire when

exposed to conditions which cause their break-down.  They don't rate
their ability to function as "surge protectors".

UL evaluates surge suppressors for fire, electric shock and personal
injury hazards, and also measures and categorizes the devices for how
much voltage they can "clamp," thus preventing excess voltage from
passing through to electronic equipment. UL refers to this as a
"suppressed voltage rating," with ranges from 330V (volts) to 4000V.
Believe it or not, the lower the rating, the better the protection.

Whatever surge suppression protection you're looking for, make sure
the surge suppressor has been tested and Listed to the stringent
requirements of UL 1449, the Standard for Transient Voltage Surge
Suppressors.

http://www.ul.com/consumers/surge.html

http://ulstandardsinfonet.ul.com/tocs/tocs.asp?doc=s&fn=1449.toc

 

[flyboy]

How can one find this rating for a particular device?

Look for ul1449 330v or 400 for example, or surge voltage rating SVR
330v or Clamping Category 330v

"The unpredictable nature of surges makes it difficult to suppress them;
you never know when, how long or how powerful they will be. In some
cases, asurgemay have a higher energy level than the device can
handle. When this happens, thesurgesuppressor may be damaged and lose
its ability to provide protection against future surges."

MOV’s and surge protectors are like tires on your car, the more you
use them the shorter useful life, mistreat them, the shorter the
useful life, too small or light weight the shorter the useful life.
Ul 1449 certification take care of the too small or light weight.
Proper selection for problem locations is the key to protection.

I'm happy to see that UL agrees!  They don't seem to put any evaluation
of this parameter, unless the "suppressed voltage rating" includes the
Jules rating of the MOVs.

Don’t pay attention to joules on surge protectors, no standard to
measure, a better and recommended rating is “Peak Surge Current” the
higher the better.

 

[Rich Grise]

What kind of ground rods? I prefer steel core, copper clad ones I even
have the special heavy hammer>

I saw one in one of the "Popular this-n-that" mags, that used a piece of
copper pipe, with a hose fitting on the end. You point the pipe at the
ground, turn on the hose, and the water digs its hole for it. Then, you
can take the hose fitting off, cap the pipe, and have a pretty decent
ground stake.

Maybe it was one of the ham mags.

Cheers!
Rich

 

[w_tom]

And as usual, W_'s statement taken at face value is wrong and/or
misleading. A simple check of history shows Saddam did in fact have
WMDs for years, because they were used in war and against his own
people.

Read Duelfer's report. Learn facts before posting. When David
Kay's report said WMDs did not exist, then extremists had Kay's report
withheld hoping that Charles Duelfer’s report would say otherwise.
Instead, Duelfer’s report said what Kay's report said - and more.
Those WMDs did not exist.

trader should first learn before knowing. trader's constant
bickering is directly traceable to knowledge with first learning
facts. Another indication of that, his problem, are posts full of
insults rather than technical facts. When will trader post a technical
facts or citation? trader even denies what was well documented about
Saddam's WMDs. No wonder he also posts insults that only Rush
Limbaugh would be proud of.

Meanwhile, a protector is only as effective as its earth ground
which is why one 'whole house' protector is *routine* for effective
household surge protection. Which is why responsible homeowners also
inspect their primary surge protection:
http://www.tvtower.com/fpl.html
trader also denies this despite a long list of industry professionals
that trader never bothered to learn from.

Another professional standard contradicts naysayers such as trader.
IEEE Green Book (IEEE Std 142) entitled 'Static and Lightning
Protection Grounding':

Lightning cannot be prevented; it can only be intercepted or
diverted to a path which will, if well designed and constructed,
not result in damage. Even this means is not positive,
providing only 99.5-99.9% protection. ...
Still, a 99.5% protection level will reduce the incidence of direct
strokes from one stroke per 30 years ... to one stroke per
6000 years ...

Significantly effective is only one 'whole house' protector.
Protector for about $1 per protected appliance. How much for the
ineffective plug-in protector? $25 or $150 per protected
appliance. Where does that plug-in protector even claim to protect
from typically destructive surges? No plug-in manufacturer
specification exists. It does not even claim to protect from the
typically destructive sruge. IEEE is quite blunt about effective
protection from a properly earthed 'whole house' protector. Unlike
trader, I even provide numbers.

trader never read industry standards. Unnecessary. trader
automatically knows without first learning.

 

[w_tom]

How can one find this rating for a particular device?

UL makes no effort to measure a protector's protective ability. In
fact, protectors can completely fail during a UL certification test
and still obtain UL approval. It failed without emitting sparks or
flame; therefore UL approved.

Approval may be obtained by undersizing MOV's thermal fuses so that
a protector will disconnect MOVs faster during a surge; leave the
appliance to fend for itself. Undersized surge protector simply
disconnects faster to obtain UL1449 approval. How might it get that
approval? Provide even less protection so as to not spit flame.

Also required for UL approval is total number of joules. That says
nothing about how many joules actually participate in protection.
Typically, plug-in protectors use as little as 1/3rd and never more
than 2/3rd of its joules for protection. If a protector is also for
cable, telephone, network, etc, then that protector may use even less
joules during protection.

A 'whole house' protector uses all joules during all types of
surges. What happens when more joules actually participate in
protection? Well, doubling the numbers of 'used' joules typically
increases a protector’s life expectancy by a factor of eight. As
joules increase, the life expectancy of the protector increases
exponentially. As joules increase, more energy gets dissipated in
earth and less energy gets dissipated inside the protector. Increase
joules to absorb less energy and to exponentially increase protector's
life expectancy.

Minimal 'whole house' protector for a home is 1000 joules and 50,000
amp surges. In locations where surges occur more frequently, a larger
joule protector is installed. Increased joules means increases
protector life expectancy.

How effective are 'whole house' protectors? Well, a friend suffered
when the 33,000+ volt transmission line fell upon his 4000 volt
distribution line. Literally everyone powered from that B phase had
electric meters explode up to 30 feet from their pans. Many had
damage to plug-in protectors and to powered off appliances plugged
into those protectors. But my friend suffered no damage, except to a
meter that exploded off his building. He had a properly earthed
'whole house' protector. A protector is not rated to provide that
protection. But properly installed protectors with sufficient joules
will provide more protection than rated.

Which protectors actually provide better protection? Products from
a list of responsible manufacturers such as Intermatic, Square D,
Siemens, Polyphaser, GE, Cutler-Hammer, Keison, and Leviton.
Specifically not on that list are APC, Tripplite, Belkin, and Monster
Cable.