Surge / Ground / Lightning

On May 6, 10:54 am, Jitt wrote:
I suppose I phrased the question badly. I wonder why a surge
would wander around looking for ground, when its available
in the box!

If all grounds are same, then connect lightning rods into a
motherboard ground. That would be perfect building protection because
a lightning rod is grounded?

Ground inside a stereo is different from ground inside a TV is
different from ground on the computer case is different from ground on
a wall receptacle is different from ground inside a cell phone is
different from a ground inside a breaker box is different from ground
in earth. Most all those grounds are interconnected and are still not
the same ground.

Electricity is different at both ends of a wire. That 100 amp surge
seeking earth from a wall receptacle may leave the wall receptacles at
12,000 volts - again, due to wire impedance. That plug-in protector
on Page 42 Figure 8 was so far from earth ground (via AC electric
wire) as to be 8000 volts - a destructive path via an adjacent TV to
earth.

The EE Times article entitled "Protecting Electrical Devices from
Lightning Transients" defines why a ground in a box is not a ground to
surges. Why electricity at both ends of a wire is always different.
Why that difference during a surge is so important that an effective
protection makes a 'less than 10 foot' connection to earth. Only
relevant 'ground' is the one that is ground to a surge. That is not
an 'inside the box' ground.

Typically destructive surges are an electrical connection from a
cloud to earthborne charges maybe miles away - the relevant ground.
If any part of that connection is via an appliance, then the appliance
may be damaged. Surge protection has always been about diverting a
connection from cloud to earthborne charges so that current need not
pass inside the building.

A protector is only as effective as its earth ground so that surges
need not enter a building. No earth ground means no effective
protection; means a surge creates connections to earth destructively
inside a building. Any facility that installs effective protection
does earthing connected, very short, via a 'whole house' type
protector.

Polyphaser makes a protector that has NO earth ground connection.
Earthing is so critical that their protector mounts directly ON the
earthing electrode - zero feet from earth ground. Distance to earth
ground is critical for effective protection. Which ground? Earth
ground is not found and not provide in three wire AC wall
receptacles. That is a safety ground.

On May 6, 12:08 pm, "Michael A. Terrell"
wrote:
Where did I say HOW was protected? It was my second week at that
station, and the chief engineer took off on a long overdue vacation. If
you would learn to read, rather than just do mindless rants you wouldn't
look so stupid. At that time the building had a UFER ground, and a
three phase protection system at the meter CTs. That didn't prevent the
damage, as you claim it should.

Lightning created damage. Since Michael Terrell says it had an Ufer
ground, that means grounding was properly installed and not
corrupted? Therefore the resulting damage proves, "Woe is me.
Nothing can protect from lightning."? Nonsense.

Damage was created by a surge. A responsible human locates the
defect in that protection system. Michael Terrell was defeatist. He
'knew' nothing can earthing lightning without damage.

Then Michael posts nonsense about other protectors so he need not
admit this fact: MOVs are not used on telephone lines. Why discuss
fuses? Fuses obviously are not for surge protection - when one has
basic electrical knowledge. Effective protectors (even gas discharge
tubes - GDTs) earth direct lightning strikes and remain functional.

So why is Michael now discussing GDTs and fuses? Michael has again
been caught posting in error. MOVs are not used for telephone line
surge protection due to excessive capacitance. This has long been
common knowledge among those who post facts - not insults. Nnoted and
finally admitted by Michael is a reasons why so little lightning in
the UK creates so much damage. Master sockets are not even earthed as
the equivlant NID is, routinely, in all North America.

Responsible people who suffer surge damage immediately search for
the human failure that made damage possible. Search typically begins
by looking for defects in the single point earth ground system. Those
who promote magic box plug-in protectors would not do this and must
assume lightning damage cannot be avoided - a defeatist attitude.

On May 6, 3:08 pm, wrote:
W_ denies MOVs are commonly used in typical electonics or modern
appliances too. He had to, because he can't answer the obvious
question of how MOVs can be used effectively in these applications,
yet they can't work in plug-in protectors and the only way to get any
protection is to have a nearby direct earth ground. Faced with the
problem of MOVs providing protection in electronics/appliance without
an earthground, he simply denies MOVs are used in electronics and
appliances. ...

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.

Reality: all appliances contain protection using numerous techniques
such as galvanic isolation. Protection that means all but a rare and
typically destructive surge is made irrelevant. Internal appliance
protection is dependent on a properly earthed 'whole house'
protector. The typically destructive surge must be earthed to not
overwhelm protection inside all appliances.

On May 6, 10:22 am, Eric wrote:
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

In article
..com, w_tom writes

[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_****.
I hereby invoke Godwin's law.

--
(\__/) Bunny says NO to Windows Vista!
(='.'=) http://www.cs.auckland.ac.nz/~pgut00...ista_cost.html
(")_(") http://www.cypherpunks.to/~peter/vista.pdf

On May 7, 12:36*am, Mike Tomlinson wrote:
In article
.com, w_tom writes

[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_****. *
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.





--
(\__/) * Bunny says NO to Windows Vista!
(='.'=) *http://www.cs.auckland.ac.nz/~pgut00...ista_cost.html
(")_(") *http://www.cypherpunks.to/~peter/vista.pdf

w_tom wrote:

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

On May 6, 2:42*am, w_tom wrote:
* *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?

wrote:

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

On May 6, 9:52*pm, w_tom wrote:
On May 6, 3:08 pm, wrote:

W_ *denies MOVs are commonly used in typical electonics or modern
appliances too. * He had to, because he can't answer the obvious
question of how MOVs can be used effectively in these applications,
yet they can't work in plug-in protectors and the only way to get any
protection is to have a nearby direct earth ground. * Faced with the
problem of MOVs providing protection in electronics/appliance without
an earthground, he simply denies MOVs are used in electronics and
appliances. *...

* 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.






* Reality: all appliances contain protection using numerous techniques
such as galvanic isolation. *Protection that means all but a rare and
typically destructive surge is made irrelevant. *Internal appliance
protection is dependent on a properly earthed 'whole house'
protector. *The typically destructive surge must be earthed to not
overwhelm protection inside all appliances.