Surge / Ground / Lightning

[w_tom]

I don't agree with that assessment of the plug-in protector. If the
appliance has its own MOVs to protect stuff, then this would be true.
Not all do. Some appliances are more sensitive than others. It just
depends on what kind of surge is arriving, and where from. If it is
differential mode on the power wires, the plug-in protector can do
some important protection. Even with whole house protection in place,
you can have some energy get past it, and the surge can be induced into
the building wiring. Usually the induced surge is common mode, which
by itself is less of a problem.

In short, your post is saying what my post said. 120 volt
electronics have long had protection up to 600 volts as defined by
industry standards. This was always accomplished without MOVs.
Notice all the dimmer switches replaced weekly due to surge damage?
Not replaced because even those devices contain significant internal
protection - without MOVs.

The differential mode surge (what a plug-in protector can protect
from) typically does no damage as indicated by the large numbers of
appliances - even smoke detectors - that survive these trivial
surges. Survive without MOV protectors because internal protetion is
provided as part of the design - not an add on provided by MOVs.

The typically destructive surge occurs maybe one every seven years.
This is the surge that must be earthing before entering building.
This is the surge that so easily overwhelms protection inside
appliances. This is the surge that makes the properly earthing 'whole
house' protector necessary and so effective.

Yes, it is possible to make other protectors - absorption type.
Industry benchmarks also provide other examples including bulkheads.
Surges running through these bulkheads are further impeded. But each
is supplementary protection. To be effective, typically quite large
or expensive (Surgex, Brickwall, Zerosurge, etc). . How much is one
willing to spend? Effective supplmentary protection is also quite
expensive. Anything less is already found inside an appliance.

Yes, a plug-in protector can provide protection. Does it increase
protection by 80% or 95%. Protection so massive that the homeowner
may never see another surge in his lifetime?. Even a simplest
(properly installed) 'whole house' protector should provide protection
that significant. Without that 'whole hosue' protector, then plug-in
protectors may even contribute to appliance damage. To be effective -
to not contribute to damage of an adjacent appliance, a plug-in
protector needs a properly earthed 'whole house' system. Again, I
have not talked pass Bud. Bud promotes supplemental protection as a
complete solution. Defined by you and I are a surge a plug-in
protector might protect from AND why a plug-in protector can also
contribute to appliance damage.

Yes, your TV antenna examples are also correct - including how
either can be damaged. That being too complicated for most readers
AND irrelevant if both antenna wires are properly installed. Before
antenna wires enter a building, both antenna wires must first make a
short connection to the single point earth ground - meaning protection
standard in TV tuners should not be overwhelmed. Same protection also
installed by the cable company.

Only Bud is limiting himself to one aspect of the issue. You and I
are both discussing the many types of surges including the other that
typically causes most damage. Bud must ignore that typically
destructive surge. Those surges also create Page 42 Figure 8 - 8000
volt earthed destructively through an adjacent TV. Those surges are
why his other citation says:

The best surge protection in the world can
be useless if grounding is not done properly.

Those surges that typically do damage AND that plug-in protectors do
not claim to protect from - Bud ignores that entire discussion.

 

[Don Kelly]

----------------------------

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.

1)Current (not current flow which is meaningless) is NOT energy.
Current*voltage*time IS energy-
..
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"

As to the advantage of "whole house" vs local surge protection, "whole house
protection depends on distances to all "protected" items being small. Local
protection doesn't but is simply that- local. The effectiveness of either
depends considerably on grounding and other factors.

The spate of name calling doesn't do anything of use to anybody.

 

[w_tom]

Bud has provided 2 sources that directly contradict Phil. (Of course
they are not as smart as Phil.)

Phil has provided no sources to support Phil's Phantasy Physics.

Every Bud citations contradicts Bud's claims. So Bud must do what
those without knowledge do - post insults.

Bud claims his plug-in protectors provide complete protection.
Good. Bud can post those manufacture spec numbers that list each type
of surge and protection from that surge. Oh. 400 requests and Bud
still cannot provide any specs? So Bud must post insults.

How to identify the liar - who does exactly what Rush Limbaugh
does? He posts no facts (no manufacturer spec numbers) and his posts
are only insults. Bud posts only insults. That says Bud lies (and
that he has not technical facts). But then profits are at risk. That
justifies anything.

 

[bud--]

| |
|>
|> 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.
|
| Why would you assume that 50% will go each way when you don't know the
| impedance of each direction? When conducting, or at failure, the MOV has a
| very low impedance.

There is a distinction between "go each way" and "what comes back" due to
the impedance. It will be about 50% that goes each way _because_ the power
itself does not (yet) know the impedance (at a distance), until it gets
there.

Another installment of Phil's Phantasy Physics using transmission line
theory.

Two sources directly contradict Phil.

Phil has provided no sources to support phantasy physics.

 

[w_tom]

...
And you are again discounting a guide written by experts, peer reviewed
by experts, published by the IEEE, and aimed at technical people. You
apparently think electrical engineers are idiots. Where you disagree
with the guide you have not cited a source that supports your belief.
...
Francois Martzloff was the surge guru at the NIST and has many published
papers on surges and suppression.

Both of Bud's citations - guides for laymen - describe how a plug-in
protector can work AND how such devices can even create appliance
damage. Both state what an effective protector needs - short
connection to earth ground. Both state why a protector without
earthing can even contribute to appliance damage.

Even Martzloff is quite blunt about this. Bud quotes from Martzloff
selectively. Meanwhile this conclusion is so fundamental that
Martzloff makes it the first point in his IEEE paper:

Conclusion:
1) Quantitative measurements in the Upside-Down house clearly
show objectionable difference in reference voltages. These occur
even when or perhaps because, surge protective devices are
present at the point of connection of appliances.

A plug-in (point of connection) protector can contribute to
appliance damage. Every Bud citation says that. Even Martzloff says
that. Why do professionals routinely install 'whole house' type
protectors instead of plug-in protectors? "Objectionable difference
in … voltages ... [when] protective devices are ... at the point of
connection". Industry professionals note this problem with plug-in
protectors. Also are those 'scary pictures of plug-in protectors
located where fire hazards are greater. Bud conveniently ignores all
that. Profits are at risk.

 

[w_tom]

Bullshit. Transmitters get knocked off the air, and the anteanna
grounding systems are damaged from repeated strikes. Onece again, you
are blowing smoke.

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.

Others who bother to learn discover what happens when a radio
station repeatedly gets knocked off the air. Eventually that station
engineer may hire someone who knows more than a TV repairman. What
was the solution to so much radio station damage? They fixed mistakes
made by a naive station engineer. They installed and upgreaded
earthing. No more lightning damage.

Michael will deny reality because Michael knows without first
learning facts. Others can learn what Michael Terrell denies.
Lightning need not cause damage when one thinks, instead, like an
engineer. Michael Terrell who learned to think like and engineer -
not like the technician - would know this. Radio station repeatedly
damaged. Then they finally admited that failure is not acceptable:
http://www.copper.org/applications/electrical/pq/casestudy/nebraska.html

Based on a belief that "too much" grounding was attracting
lightning strikes, grounding connections on the tower's six
sets of guy wires had been disconnected sometime in the
past (Figure 4). This action may, in fact, have helped direct
lightning discharge current down the antenna tower itself,
bringing the strike closer to the studio/transmitter building.

Why did the station engineer make damage easier? He could not
bother to learn about stuff even published in QST magazine - the ham
radio operator's magazine.

Why does Michael Terrell deny this? He is a technician - a TV
repairman. His posts attack the messenger rather than address
technology. Michael Terrell is correct. Some stations are knocked
off the air by lightning. Those with informed station engineers
correct the defect - learn from their mistakes and eliminate future
failures. Michael Terrell's attitude declares failure as acceptable.
But then Michael Terrell could not think like an engineer which is why
he also could never be promoted above enlistedman.

 

[G-squared]

"w_tom" <[email protected]> wrote in message


Why do you have this pompous attitude; constantly sermonizing down to people
as if they're your little, personal kindergarten class?

You read sometimes like one of those old children's "Golden Books".

Hey, I LIKED reading Golden Books to my kids. They didn't like W-TOMs
posts at all.

GG

 

[krw]

Every Bud citations contradicts Bud's claims.

Don't be so stupid.

So Bud must do what
those without knowledge do - post insults.

Anything truthful posted about you would be an insult to a normal
person.

Bud claims his plug-in protectors provide complete protection.

Bullshit. Either you're a goddamned liar or are denser than a
concrete slab. He's repeatedly said there is *no* protection from a
direct strike (except to be elsewhere).

Good. Bud can post those manufacture spec numbers that list each type
of surge and protection from that surge. Oh. 400 requests and Bud
still cannot provide any specs? So Bud must post insults.

Ok, that answers it. You *are* a liar.

How to identify the liar - who does exactly what Rush Limbaugh
does? He posts no facts (no manufacturer spec numbers) and his posts
are only insults. Bud posts only insults. That says Bud lies (and
that he has not technical facts). But then profits are at risk. That
justifies anything.

There goes W, doing what he claims others do; not only stupid, but a
liar and hypocrite, to boot.

 

[w_tom]

...
The same thing said eight times. Part of w_tom's modus operandi -
repeat something enough times and it must be true.

If must be said eight times - and still not understood by trader -
because that is the point. He does not want to understand it.

BTW, prim and proper Englishmen insist we must never mix first,
second, and third person. They don't worry about being misinterpreted
since misinterpretation is part of being prim and proper.

Better is to mix first and third person often so that the only
thing important - the message - cannot be misconstrued. If he chooses
to do so, no problem. If w_tom chooses to do so, no problem. If I
choose to do so, no problem. Exact same meaning to everyone except
the prim and proper Englishman who would now get all caught up in a
tizzy.

No problem. trader still will deny a fact stated eight times.

All appliances contain internal protection. That protection is not
provided by MOVs no matter how many times trader says otherwise.
Protection that may be overwhelmed if the typically destructive surge
is not earthed by a 'whole house' protector. Facts remain no matter
which person is used.

Again, referring to trader's latest myth: increasingly complex
electronics now contain even better protection than those earlier,
less complex electronics. Today, international standard now require
signal interface ICs to withstand 2000 and 15,000 volts without
damage. Previous interfaces in less complex electronics could only
withstand 30 or 40 volts. trader should have known these numbers long
before he posted more myths. Increasing complex electronics are even
more robust - less likely to suffer surge damage. But again, trader
knew long before learning any facts.

 

[w_tom]

Why do you have this pompous attitude; constantly sermonizing down to people
as if they're your little, personal kindergarten class?

Ask polite or technical questions, and get straight honest
responses. If you think my tone was offensive, then review your
original post. Post like an emotional child and get a stern response.

Franc Zabkar asked a question without an incendiary intent.
Therefore a straight and honest answer. My posts to you was blunt and
honest. How blunt? It did not contain a single insulting statement or
implication. It was a hard straight answer - nothing more. And it was
appropriately terse where you make claims or denial without any
supporting facts. If you need sweet words, go find a spouse. Was
your question incendiary or based in technical curiosity?

You were neither mocked nor insulted. Your technical mistakes were
corrected accurately. Neither your emotions nor your children have a
place here. This is a technical discussion about an unpopular reality
– about facts known even 100 years ago and that contradict both
popular urban legend and retail store propaganda.

Nobody - you, me, or anyone else (should) cares about your
emotions. Your emotions don't belong in a technical discussion. You
were not mocked or insulted - just technically replied to. You don't
like the tone. Your first post set the tone. Anything after that was
simply your reflection in a mirror.

 

[Guest]

| (e-mail address removed) wrote:
|> | (e-mail address removed) wrote:
|>
|> |> | You suggest experts in the field "missed a lot of reality" and "flubbed
|> |> | the experiment".
|> |>
|> |> I propose that as one explanation as to why these guides come up short on
|> |> the explanations.
|> |
|> | Translation - they don't say what you believe. They "missed a lot of
|> | reality" was in response to one of your beliefs that is not found in any
|> | of the rather extensive reading I have done. And another of your beliefs
|> | for which you have no supporting cite.
|>
|> You are likely to never see any citation that attests to what I believe.
|
| Because some of what you believe has nothing to do with the real world.

Which somes are that?


|> | And you are again discounting a guide written by experts, peer reviewed
|> | by experts, published by the IEEE, and aimed at technical people. You
|> | apparently think electrical engineers are idiots. Where you disagree
|> | with the guide you have not cited a source that supports your belief.
|>
|> I've _met_ electrical engineers that are idiots. I've met people in a
|> lot of other fields that are idiots.
|>
|> I don't know if the authors of what you have read are idiots. Maybe they
|> are just not writing as broadly as you think they are.
|
| Of course they are idiots. They are all members of the IEEE. Only idiots
| can join. And only the biggest idiots can write publications for the IEEE.

Your words, not mine.


| Martzloff is not only an IEEE idiot. He worked for the NIST - another
| well known lair of idiots.

Your words, not mine.


| Thank goodness you aren?t a member.

Yeah, right.


|> |> For example, consider the high frequency issue. High frequency energy is
|> |> less common than low frequency energy. Partly this is because the chance
|> |> of a closer lightning strike is less than a more distant one. A strike
|> |> within 100 meters is only 1/8 as like as a strike outside of 100 meters
|> |> but within 300 meters. Some people then feel that they can dismiss high
|> |> frequency energy issues entirely.
|> |
|> | Francois Martzloff was the surge guru at the NIST and has many published
|> | papers on surges and suppression. In one of them he wrote:
|> | "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 the front of the wave is not shorter than
|> | the travel time of the impulse. 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."
|> | Residential branch circuits aren't 200m.
|> |
|> | Your response: "Then he flubbed the experiment." In another case you
|> | have said Martzloff had a hidden agenda.
|>
|> I addressed this one elsewhere. You seem to have misunderstood him.
|> He did not say that wiring systems do not exhibit transmission line
|> characteristics.
|
| If you had actually read the quote:
| "*it is not appropriate to apply classical transmission line concepts to
| wiring systems*"
| and "*this means that the line must be at least 200 m long before one
| can think in terms of classical transmission line behavior*."
|
| Repeating: "Residential branch circuits aren't 200m."

You are now taking what Martzloff said out of context. He _qualified_
what he said in terms of a statement conditional. Following the part
you just now quoted is "... if the front of the wave is not shorter than
the travel time of the impulse." Then he added "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."

Hint: what "if" means is that if the conditional is not met, then the
statement does not apply.

Martzloff's statement is actually correct. Your quoting of it is wrong.
I suspect your understanding of it is weak or maybe even wrong. I believe
you are misapplying it. Then when _my_ statement contradicts _your_
incorrect understanding, you somehow think *I* am contradicting him.

His statement is qualified for a specific slow impulse rise time that
corresponds to a lower frequency. He has NOT said (in what you quoted
in earlier posts here) that no surge can ever have a faster rise time.
He has NOT said that you cannot think in terms of transmission line
behaviour for faster rise times, even on shorter wiring/circuits.

I recall there being something he said that I would contradict, but THIS
statement is NOT it.


|> Rather, he points out that one does not need to look
|> at the transmission line characteristics in certain cases.
|
| Like branch circuits under 200 meters long.

See description of your error above.


|> | You claim lightning induced surges have rise times about a thousand
|> | times faster than accepted IEEE standards - which are experimentally
|> | derived.
|>
|> So you are narrowing this statement to only induced surges?
|
| I intended "induced" meaning produced by including the most damaging -
| strikes to utility lines.

The most damaging strikes tend to be ones that are NOT induced. Do you
understand what induction and inductive coupling is?

Lightning does not have to directly strike the wire for there to be a
surge on it. That is induction when there is no direct strike. If the
strike _is_ directly on the wires, that's different (and has the exposure
of substantially more voltage/current).


|> I didn't see where you quoted anything by IEEE or its experts that specify
|> actual rise times of any kind of surge, induced or otherwise.
|
| From the Martzloff quote you didn't read:
| "For a 1.2/50 us impulse". That is 1.2 microseconds rise time.

Oh I read it. You are making presumptions because I did not conclude
the same thing you concluded.

Because he said "For a ...", he is describing an example scenario and
giving the calculated line length where transmission line effects become
significant enough to consider.


| From w_'s favorite engineer source "an 8 microsecond rise time".
|
| Don?t you read anything?

If you had simply said "Don't you read _everything_" then I would have
agreed with you. And that would be because I actually do not read a
lot of, or maybe most of, w_tom posts. I don't even see them all
because he is posting from Google Groups. So I don't know what, or
how much, I missed from him.

And I don't care.

OTOH, I have read the original quotes of Martzloff's statements that you
made, and then I read the subsequent quotes where you have trimmed them
to change the apparent context to support assertions you seem to be making
that Martzloff is not actually supporting.


| The numbers come from an IEEE standard - accepted by everyone but you.

The numbers are example cases. Read what YOU QUOTED ... CAREFULLY!


|> | One of w_'s favorite professional engineer sources says an 8 microsecond
|> | rise time for a lightning induced surge is a "representative pulse",
|> | with most of the spectrum under 100kHz. You don?t get transmission line
|> | effects at 100kHz.
|>
|> I agree that you don't get transmission line effects under 100 kHz for 200m
|> wires ... of any significance to worry about for surge matters.
|>
|> OTOH, you have not shown how even if an 8 microsecond rise time is significant
|> as a representative case, that it can't get shorter than that in severe cases.
|> or even a higher rise voltage (which hasn't even been specified at all here).
|
| I provided 2 direct sources. They follow IEEE standards for rise time.
|
| Still never seen - a cite that supports your opinion.

Why should I even bother? The more you post, and the more you take things
out of context, and the more you misunderstand what you quote, the more I
realize there is no point in making further efforts for you.


| It is Phil?s phantasy physics.

Or Bud's fantasy prose?

 

[Guest]

| (e-mail address removed) wrote:
|> | |> |
|> |>
|> |> 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.
|> |
|> | Why would you assume that 50% will go each way when you don't know the
|> | impedance of each direction? When conducting, or at failure, the MOV has a
|> | very low impedance.
|>
|> There is a distinction between "go each way" and "what comes back" due to
|> the impedance. It will be about 50% that goes each way _because_ the power
|> itself does not (yet) know the impedance (at a distance), until it gets
|> there.
|
| Another installment of Phil's Phantasy Physics using transmission line
| theory.

Not understanding it is your loss.


| Two sources directly contradict Phil.

What sources? Your truncated out of context quotes?


| Phil has provided no sources to support phantasy physics.

I don't care.

 

[Guest]

| (e-mail address removed) wrote:
|>
|> Bud is focusing on the low frequency energy and
|> seems to think that is all there us because a lot of documents focus
|> on it because more energy is in the low frequencies. Also, surges
|> that come from a greater distance have the higher frequencies reduced.
|>
|> Bud either does not understand the high frequency energy or just does
|> not believe it can happen. All lightning strikes have it.
|
| Bud has provided 2 sources that directly contradict Phil. (Of course
| they are not as smart as Phil.)

Bud has quoted people like Martzloff out of context.


| Phil has provided no sources to support Phil's Phantasy Physics.

Phil doesn't care.


| (But this is *Phil* - why should he need sources?)

Why should he care?

 

[Guest]

| (e-mail address removed) wrote:
|>
|> | As always, "w_tom" ignores that the high voltages that short out
|> | "3 miles of sky" will short out the underground power lines which
|> | enter my building and buildings all over America. Anything able to
|> | leap "3 miles of sky" will leap the fraction of an inch between the
|> | power lines and the earthed metal conduit. What is left will be a
|> | much lower voltage spike that can be handled by the average
|> | "plug-in protector".
|>
|> It does not always make the 2nd leap to ground. There is not always a metal
|> conduit available. I've seen such strikes.
|
|
| With no service panel suppressor it is well accepted that at about 6kV
| there will be arc-over from bus to enclosure for (US) circuit breaker
| panels. While arcing, the voltage will be hundreds of volts. Since the
| panel/system ground is connected to the earth electrode (US) most of
| surge energy is dumped to earth.

But what is remaining, in a significant surge, is still capable of causing
damage. A surge already has some high frequency energy. That moves on past
the point of arc even before the arc happens. Once the arc is established,
it can then produce its own high frequency effects. Ignoring this leaves
you open to more damage.


| If talking about a plug-in suppressor, Experiments by Martzloff (the
| idiot/member-of-the-IEEE) show surprisingly little energy reaches the
| suppressor. Circuit impedance greatly limits the current, and thus
| energy. Surprisingly, there is more energy at the MOV for lower surge
| currents (on short branch circuits) because the MOV can hold the panel
| voltage below the 6kV breakover voltage. With up to 10kA surges, the max
| energy at the MOV was 34J with most cases below 1.2J.

I've seen surge energy reach an appliance that is significant enough to cause
complete melt through of AWG #8 copper conductors. There was no protection
installed in that particular case.

 

[Guest]

Same is described by van Deursen and van der Laan when lightning
caused damage to a nuclear hardened maritime radio station. Did they
cry, "Woe is me. Nothing can stop lightning damage"? Of course not.

Nono. They cried "w_tom is me. Stop lightning damage I can."

Nick

 

[Jitt]

(e-mail address removed)>, (e-mail address removed)
says...

Path to earth was through the network and into a third computer.
Through that third computer's motherboard, through modem, and to earth
via phone lines. Semiconductors in these paths were damaged.

We literally traced this path by replacing ICs. Some ICs (ie
network interface chips) even had cracks on packages where surge
current entered or exiting those ICs. Absolutely no doubt as to how
surge currents found earth ground, destructively, via adjacent
computers.

I wonder why, since electrical codes in North America
and Britain require a ground connection at each outlet;
computer power cords are 3 wire?

 

[Dave]

I wonder why, since electrical codes in North America
and Britain require a ground connection at each outlet;
computer power cords are 3 wire?


(snip)

hot neutral ground

 

[trader4]

|> ||> |
|> |>
|> |> 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 athigher
|> |> frequencies.
|> |
|> | Why would you assume that 50% will go each way when you don't know the
|> | impedance of each direction?  When conducting, or at failure, the MOV has a
|> | very low impedance.
|>
|> There is a distinction between "go each way" and "what comes back" due to
|> the impedance.  It will be about 50% that goes each way _because_ thepower
|> itself does not (yet) know the impedance (at a distance), until it gets
|> there.
|
| Another installment of Phil's Phantasy Physics using transmission line
| theory.

Not understanding it is your loss.

I have to agree that this is Phantasy Physics. We're supposed to
believe that a surge reaching a MOV is going to split 50-50, with half
of it going to the MOV path and half moving on down the line,
reagrdless of the impedance of the two paths? That would render all
surge protection about 50% effective.

 

[Tzortzakakis Dimitrios]

He an obsessive-compulsive disorder victim, apparently driven by some kind
of bizarre fetish involving ground rods.

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

 

[trader4]

I wonder why, since electrical codes in North America
and Britain require a ground connection at each outlet;
computer power cords are 3 wire?

(snip)

hot neutral ground

Meanwhile, I'm still waiting for an explanation from w_ about how
surege protection inside that computer can work? Where is that
direct connection to earth ground, without which w_ says surge
protection is impossible? Does the computer have a mythical earth
ground inside? The answer is it doesn't. It is acting under exactly
the same limitations and uses the same components, typically MOVs to
do what a plug-in surge supressor does. w-'s answer to this is to
claim that electronics, appliances, etc do not use MOVs, a claim
previously smashed, because of course they do. Plus it really has
nothing much to do with the question anyway, because the computer,
appliance, etc still HAS NO DIRECT EARTH GROUND, without which w- says
protection is impossible.