On Monday, October 26, 2015 at 9:52:52 AM UTC-4, westom wrote:
On Monday, October 26, 2015 at 12:19:21 AM UTC-4, Muggles wrote:
This is an interesting topic, for sure, and I'm just dipping my toe in
it when there's a whole ocean of information.

Unfortunately, protection is about earthing - not about oceans.

Unfortunately, you're as clueless as ever. A Boeing 777 has surge
protection and it has no wire trailing behind, connected to earth.

Hint: It uses some of the same techniques that plug-in surge
protectors use.

But Tom will never learn. Maybe some of those that read the post
though will.

On Mon, 26 Oct 2015 06:49:54 -0700 (PDT), westom
wrote:

On Monday, October 26, 2015 at 12:02:16 AM UTC-4, Muggles wrote:
I don't really expect the back-up to protect from a major lightning
strike. It's more to protect from power surges like when the wind is
blowing and the power goes off briefly and back on again.

Those are sags or blackouts - not surges. A UPS would provide temporary power so that a reboot need not happen.

A surge is a high voltage. Power outage or dimming is a low voltage - not a surge.
When the power comes back on, particularly in those storm situations
where the power never really goes "out" but the lights blink - THAT is
when you get real "surges" - not to confused with the high amperage
high voltage "spikes" created by lightning. They can damage sensitive
electronics over time.

Any inductive loads on the line store energy and release it when the
power colapses,

On Mon, 26 Oct 2015 06:52:48 -0700 (PDT), westom
wrote:

On Monday, October 26, 2015 at 12:19:21 AM UTC-4, Muggles wrote:
This is an interesting topic, for sure, and I'm just dipping my toe in
it when there's a whole ocean of information.

Unfortunately, protection is about earthing - not about oceans.
Simple surge protection ( not talking ligtning) can also be simply
clamping the voltage line to neutral with no ground involvement.
Varistors do this quite effectively. A more accurate description of
the power anomoly we are talking about is a "transient" - and the
devices are often referred to as "transorbs"
They (the anomolies) can also be referred to a "pulses".
MOV Transorbs can be connected line to line, line to neutral, or line
to ground.

On Monday, October 26, 2015 at 12:55:46 PM UTC-4, wrote:
When the power comes back on, particularly in those storm situations
where the power never really goes "out" but the lights blink - THAT is
when you get real "surges" - not to confused with the high amperage
high voltage "spikes" created by lightning. They can damage sensitive
electronics over time.

Surge is a subjective term used to describe low voltages, low currents, high voltages, radio frequency noise, and low voltages. The 'surge' discussed here is a current from a current source that will increase voltage on anything that might try to stop it. That is not the 'surge' you have described..

That type surge is already made irrelevant by what is inside appliances. For example, computers has a safety lockout. This lockout must be cleared by disconnecting its power cord from the wall. No protector claims to or will even discuss this 'surge' that is irrelevant to the topic.

If inductive loads are creating surges on AC mains, then AC power switching off 120 times a second is also creating surges. Once we include numbers, those inductive generative surges (high voltage) do not exist. Those surges are slightly higher current often associated with a reduced line voltage.

What happens when that type anomaly occurs? Depends on numbers. Some are so short that no electronics sees the short power loss. Other are so long that electronics simply power off - then restart. In both cases without any hardware damage.

This anomaly could be a problem especially with electronics in the 1950s and 60s when hardware was not as robust. Today's power supplies profit from over 100 years of design advancement.

On Monday, October 26, 2015 at 1:01:37 PM UTC-4, wrote:
MOV Transorbs can be connected line to line, line to neutral, or line
to ground.
You have confused two completely different devices. A Transorb is a semiconductor device - a type of avalanch diode. An MOV is ceramic type material - operates completely differently. Both devices have completely different failure mode characteristics, response curves, and monetary costs.

On Monday, October 26, 2015 at 12:55:46 PM UTC-4, wrote:
On Mon, 26 Oct 2015 06:49:54 -0700 (PDT), westom
wrote:

On Monday, October 26, 2015 at 12:02:16 AM UTC-4, Muggles wrote:
I don't really expect the back-up to protect from a major lightning
strike. It's more to protect from power surges like when the wind is
blowing and the power goes off briefly and back on again.

Those are sags or blackouts - not surges. A UPS would provide temporary power so that a reboot need not happen.

A surge is a high voltage. Power outage or dimming is a low voltage - not a surge.
When the power comes back on, particularly in those storm situations
where the power never really goes "out" but the lights blink - THAT is
when you get real "surges" - not to confused with the high amperage
high voltage "spikes" created by lightning. They can damage sensitive
electronics over time.

Any inductive loads on the line store energy and release it when the
power colapses,

Clearly the IEEE, NIST, etc refer to transients on power and communication
lines caused by lightning as "surges". Read the guides. Calling it
something else and saying it's not a surge, just adds to the confusion.
They sell surge protectors. Haven't seen one called a "spike" protector.

On 10/26/2015 11:01 AM, wrote:
On Mon, 26 Oct 2015 06:52:48 -0700 (PDT), westom
wrote:

On Monday, October 26, 2015 at 12:19:21 AM UTC-4, Muggles wrote:
This is an interesting topic, for sure, and I'm just dipping my toe in
it when there's a whole ocean of information.

Unfortunately, protection is about earthing - not about oceans.

That is westom's apparently religious belief, immune from challenge.
Protection is about keeping the voltage between wires at a non-damaging
level, which may or may not directly use earthing.

Since plug-in protectors are not well earthed, westom believes they can
not possibly work. With minimal reading skills he could read in the IEEE
surge guide that they work primarily by limiting the voltage from all
wires to the ground at the protector, and that plug-in protectors are
effective. But westom just ignores conflicting ideas. He is the poster
child for cognitive dissonance.

If you have a large surge current to your house's earthing system, the
"ground" potential and the building power wiring may rise thousands of
volts above 'absolute' earth potential. That may be thousands of volts
from the cable/telephone/dish/... wiring, depending on how they are
protected. Keeping the voltage between all wires at a reasonable level
is more important than minimizing the voltage to 'absolute' earth potential.

The frequent lightning strikes to airplanes are much more extreme cases
where protection is by voltage limitation, and where an earth connection
is not even required (or possible).

Simple surge protection ( not talking ligtning) can also be simply
clamping the voltage line to neutral with no ground involvement.
Varistors do this quite effectively. A more accurate description of
the power anomoly we are talking about is a "transient" - and the
devices are often referred to as "transorbs"
They (the anomolies) can also be referred to a "pulses".

"Transient" is likely the same as "surge". "Pulse" is rather ambiguous.
Protection from surges caused by lightning is not rocket science.

MOV Transorbs can be connected line to line, line to neutral, or line
to ground.

Transorbs are not MOVs (metal oxide varistors). In transorbs the voltage
limitation occurs at a semiconductor junction. MOVs have the voltage
limitation at grain boundaries throughout the device, which spreads the
heat from limitation over a much larger volume. That is why MOVs can
operate at very large currents (for a very short time).

UL listed plug-in protectors will have MOVs from H-N, H-G, and N-G. If
signal wires go through them they will also have voltage-liming from
those wires to the device ground.

On Mon, 26 Oct 2015 13:31:06 -0700 (PDT), westom
wrote:

On Monday, October 26, 2015 at 12:55:46 PM UTC-4, wrote:
When the power comes back on, particularly in those storm situations
where the power never really goes "out" but the lights blink - THAT is
when you get real "surges" - not to confused with the high amperage
high voltage "spikes" created by lightning. They can damage sensitive
electronics over time.

Surge is a subjective term used to describe low voltages, low currents, high voltages, radio frequency noise, and low voltages. The 'surge' discussed here is a current from a current source that will increase voltage on anything that might try to stop it. That is not the 'surge' you have described.

But that IS the surge most surge protectors protect against, quite
effectively. They are not DESIGNED to protect against lightning
strikes. They are designed to clean up the transients in the power .

That type surge is already made irrelevant by what is inside appliances. For example, computers has a safety lockout. This lockout must be cleared by disconnecting its power cord from the wall. No protector claims to or will even discuss this 'surge' that is irrelevant to the topic.

Pardon??? Computers have a safety lockout??? If a computer power
supply gets hit by enough transient spikes, the power supply WILL
fail, and it will fail without ever being "locked out". Particularly
with the industry standard and very common "ATX" power supply.

Yes, they have transient absorbers on them - designed to keep the
noise generated by the power supply itself from exiting into the AC
power system. It is also SOMEWHAT effective at keeping noise out of
the computer - but not nearly as effective as an external surge
protector. What is in the power supply is called an "emi filter", not
surge protection.

As far as "appliances" most have NO transient or spike or surge
protection built in.

If inductive loads are creating surges on AC mains, then AC power switching off 120 times a second is also creating surges.
No, there is a resonance in a 60 hz power supply that tends to keep
the sine wave steady and clean. When a temorary short in the power
grid, say, from wires clashing together in a storm, which causes the
lights to flash, but does not blow fuses in the grid, there is aften
a very real and measurable surge or spike when the short opens and the
power comes back on. The dt/dv or instantaneous rate of change in the
voltage doesn't follow a nice clean sine wave in these conditions and
with inductance and capacitance in the circuit the voltage can lead or
lag the current
Once we include numbers, those inductive generative surges (high voltage) do not exist. Those surges are slightly higher current often associated with a reduced line voltage.

What happens when that type anomaly occurs? Depends on numbers. Some are so short that no electronics sees the short power loss. Other are so long that electronics simply power off - then restart. In both cases without any hardware damage.

This anomaly could be a problem especially with electronics in the 1950s and 60s when hardware was not as robust. Today's power supplies profit from over 100 years of design advancement.

And they also suffer from decades of experience by the bean counters
in reducing the cost of products to the bare minimum by providing only
the absolute minimum protection. If it has a 90% chance of lasting
through warranty they'll take another 3 cents out of the cost.

In one of the offices where I work, before they moved into the
building they are in now, we were a block from a large Weston's Bakery
and a couple other smaller industries, and untill I put all the
computers on protection we were averaging a power supply every month,
and hard drives were failing at a rediculous rate. I put in real cheap
UPS units with pretty good surge protection, and out power sopply
problem virtually dissapeared - down to less than one a year - along
with the hard drive problems. (an office of, at that time, 27 PCs and
a server (which was on a Dual Conversion UPS and never had any
issues). We had a power quality analyser (dravitz?) on the line for a
week, and the power quality was "terrible"

The office moved into a brand new build ing, on a brand new power
system, with no nearby industries, and when the cheap UPS units gave
up and needed batteries the "boss" said don't bother replacing them -
and we have had virtually no power supply or hard drive issues due to
power problems.

You can say what you like - you sound suspiciously like an engineer. I
on the other hand live and work "in the real world" as a technician.

On 10/26/2015 7:48 AM, wrote:
On Sun, 25 Oct 2015 22:59:16 -0500, Muggles wrote:

On 10/24/2015 1:06 AM, wrote:
On Fri, 23 Oct 2015 23:22:17 -0500, Muggles wrote:

On 10/23/2015 11:18 PM, wrote:
On Fri, 23 Oct 2015 22:42:20 -0500, Muggles wrote:

[...]

We now have battery back-up/surge protectors for our computers that's
supposed to protect from those sort of lightning issues.

Unless they are "dual conversion" UPS units you are not getting the
protection you think you are.

Dual conversion?
Yes Also known as OnLine or full-time.. A more expensive unit that is
a "separately derived power source". AC Line voltage is converted to
DC through an isolation transformer and charges the battery. The DC is
then converted back to AC to run your computer.. There is no
switch-over time and only the ground is electrically connected to the
"mains" power.. They generally have superior surge isolation compared
to standby (the typical low end unit like an APC BackUPS) or line
interactive (the better more expensive units that can adjust line
voltage up or down without going on battery)


I'm not really understanding - at least I don't think I do. Is it like
a whole house power supply that automatically turns on when the power
goes out?
Np, it is a plug-in unit for computer and electronics use - generaly
1--1.5KVA but much larger onea are available, including units that
COULD run a whole house and ones that are hardwired for data center
use


OK ...hmmm not sure if mine is like that or not, but it works good
enough for surge protection so far.

--
Maggie

On 10/26/2015 8:49 AM, westom wrote:
On Monday, October 26, 2015 at 12:02:16 AM UTC-4, Muggles wrote:
I don't really expect the back-up to protect from a major lightning
strike. It's more to protect from power surges like when the wind is
blowing and the power goes off briefly and back on again.

Those are sags or blackouts - not surges. A UPS would provide temporary power so that a reboot need not happen.

A surge is a high voltage. Power outage or dimming is a low voltage - not a surge.


ok Thanks for the info.

--
Maggie

On 10/26/2015 8:52 AM, westom wrote:
On Monday, October 26, 2015 at 12:19:21 AM UTC-4, Muggles wrote:
This is an interesting topic, for sure, and I'm just dipping my toe in
it when there's a whole ocean of information.

Unfortunately, protection is about earthing - not about oceans.


I do understand what you've been saying about earthing. The current has
to have an entry and exit point as it's searching for it's target.

--
Maggie

On 10/26/2015 9:56 AM, trader_4 wrote:
On Monday, October 26, 2015 at 9:52:52 AM UTC-4, westom wrote:
On Monday, October 26, 2015 at 12:19:21 AM UTC-4, Muggles wrote:
This is an interesting topic, for sure, and I'm just dipping my toe in
it when there's a whole ocean of information.

Unfortunately, protection is about earthing - not about oceans.

Unfortunately, you're as clueless as ever. A Boeing 777 has surge
protection and it has no wire trailing behind, connected to earth.

Hint: It uses some of the same techniques that plug-in surge
protectors use.

But Tom will never learn. Maybe some of those that read the post
though will.


I think he's talking about things on the ground, not things in the air.

--
Maggie

On Monday, October 26, 2015 at 6:22:28 PM UTC-4, wrote:
On Mon, 26 Oct 2015 13:31:06 -0700 (PDT), westom
wrote:

On Monday, October 26, 2015 at 12:55:46 PM UTC-4, wrote:
When the power comes back on, particularly in those storm situations
where the power never really goes "out" but the lights blink - THAT is
when you get real "surges" - not to confused with the high amperage
high voltage "spikes" created by lightning. They can damage sensitive
electronics over time.

Surge is a subjective term used to describe low voltages, low currents, high voltages, radio frequency noise, and low voltages. The 'surge' discussed here is a current from a current source that will increase voltage on anything that might try to stop it. That is not the 'surge' you have described.

But that IS the surge most surge protectors protect against, quite
effectively. They are not DESIGNED to protect against lightning
strikes. They are designed to clean up the transients in the power .


Lost in the wilderness again. Do you even read any of the links?
Two guides to surge protection were provided here many times, from
the IEEE and NIST. Both talk extensively about using surge protectors
to protect against AC and communications line power surges from lightning.
In fact, they spend most of both guides talking about surges caused
by lightning. The main lightning discharge doesn't hit the PC or
even the house. It can hit utility wires a block down the street
and a nasty surge can still arrive at your PC. It's the most common
type of damaging surge encountered in homes.



That type surge is already made irrelevant by what is inside appliances. For example, computers has a safety lockout. This lockout must be cleared by disconnecting its power cord from the wall. No protector claims to or will even discuss this 'surge' that is irrelevant to the topic.

Pardon??? Computers have a safety lockout???

I think he's talking about disconnecting the power cord during
a lightning storm. You would also have to disconnect any cable,
phone etc too and of course the whole thing is impractical.



If a computer power
supply gets hit by enough transient spikes, the power supply WILL
fail, and it will fail without ever being "locked out". Particularly
with the industry standard and very common "ATX" power supply.

Yes, they have transient absorbers on them - designed to keep the
noise generated by the power supply itself from exiting into the AC
power system.

Wrong. They have surge protection, typically MOVs, just like all
other electronic appliances, to give some protection against AC
power line surges. Same thing on communication cards, eg modems,
the incoming comm lines are protected too.


It is also SOMEWHAT effective at keeping noise out of
the computer

Surge protection typically doesn't do much, if anything for noise.
It's there for surge protection.


- but not nearly as effective as an external surge
protector. What is in the power supply is called an "emi filter", not
surge protection.


You're confusing two different things, noise filtering and surge
protection.


As far as "appliances" most have NO transient or spike or surge
protection built in.


Every electronic one I've ever seen has it, eg TV, stereo, electronic
ovens, etc. An old toaster or stand mixer, they wouldn't because they
don't need it.




If inductive loads are creating surges on AC mains, then AC power switching off 120 times a second is also creating surges.
No, there is a resonance in a 60 hz power supply that tends to keep
the sine wave steady and clean. When a temorary short in the power
grid, say, from wires clashing together in a storm, which causes the
lights to flash, but does not blow fuses in the grid, there is aften
a very real and measurable surge or spike when the short opens and the
power comes back on. The dt/dv or instantaneous rate of change in the
voltage doesn't follow a nice clean sine wave in these conditions and
with inductance and capacitance in the circuit the voltage can lead or
lag the current

What happens when you turn on a switch? You have a similar effect,
power suddenly being applied. I can see power restoration possibly
causing a problem, but it sure doesn't seem to be the typical case.
When power goes out, 5,000 homes could be affected. In cases like
Sandy, it was millions. I heard of a lot of flood damage, wind damage,
but IDK of a single failure due to surges when power was restored.




You can say what you like - you sound suspiciously like an engineer. I
on the other hand live and work "in the real world" as a technician.

He doesn't sound like any engineer I've known. But interesting that
you eschew higher learning and think that engineers don't live in
the real world.

On Monday, October 26, 2015 at 7:05:15 PM UTC-4, Muggles wrote:
On 10/26/2015 9:56 AM, trader_4 wrote:
On Monday, October 26, 2015 at 9:52:52 AM UTC-4, westom wrote:
On Monday, October 26, 2015 at 12:19:21 AM UTC-4, Muggles wrote:
This is an interesting topic, for sure, and I'm just dipping my toe in
it when there's a whole ocean of information.

Unfortunately, protection is about earthing - not about oceans.

Unfortunately, you're as clueless as ever. A Boeing 777 has surge
protection and it has no wire trailing behind, connected to earth.

Hint: It uses some of the same techniques that plug-in surge
protectors use.

But Tom will never learn. Maybe some of those that read the post
though will.


I think he's talking about things on the ground, not things in the air.

--
Maggie

The point is that you're new buddy, WTom, claims that there can be no
protection against surges without an earth ground. An airplane is
protected from lightning, while it's in the air. And part of the way
they do it is using the same technique that a plug-in surge protector
uses. Of course WTom won't acknowledge or explain that. But it's
fun to keep him dancing.

You, Clare, WTom are all down a rat hole with UPS's. A UPS
will offer some protection against surges, but it's not it's
main, intended, function. You said you
had one or more PCs damaged by lightning that were using a plug-in
surge protector. I told you the most probative thing is were they
multi-port surge protectors that routed cable, phone, etc, ie any
other lines connected to the PC through it as well? Or were they ones
that were AC surge protection only? If it was the latter, your
damage is explained in the IEEE guide, section 5. You can read it
for yourself, or you can listen to loons.

http://www.lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf

On Monday, October 26, 2015 at 7:04:19 PM UTC-4, Muggles wrote:
I do understand what you've been saying about earthing. The current has
to have an entry and exit point as it's searching for it's target.

Surges that do damage are hunting for earth ground. A lightning strike is a direct connection from cloud to earthborne charges maybe 5 miles distant. A shortest electrical connection may be three miles down to earth and four miles through earth to those charges. If appliances get in that path, then damage occurs.

A direct strike to AC wires far down the street is incoming to every household appliance. Now that current must hunt for an outgoing path to earth via some appliances (and to charges maybe four miles away). If that current is connected to earth BEFORE entering a structure, then no destructive hunt exists inside the house.

Best protection for TV cable is a hardwire from cable to single point earth ground. Then a surge need not enter on TV cable.

AC electric and phone cannot connect directly to earth. So a 'whole house' protector does what that hardwire does better - connect a surge to earth.

If every wire inside every incoming cable makes a low impedance (ie less than 10 foot) connection to earth, then an incoming and outgoing path (the hunt) need not exist via appliances.

A protector is only a connecting device to what does protection. Protection is a connection to and quality of earthing electrodes at the service entrance. Every effort to improve earthing and lower impedance (ie shorten that hardwire) increases appliance protection. Then a surge is less likely to blow through protection inside appliances. A surge is less likely to find earth destructive via appliances.

Earthing is how protection was done over 100 years ago. And how it is done in every facility that cannot have damage. Protectors are only connecting devices to what really does protection - single point earth ground.

On Tuesday, October 27, 2015 at 11:02:04 AM UTC-4, westom wrote:
On Monday, October 26, 2015 at 7:04:19 PM UTC-4, Muggles wrote:
I do understand what you've been saying about earthing. The current has
to have an entry and exit point as it's searching for it's target.

Surges that do damage are hunting for earth ground. A lightning strike is a direct connection from cloud to earthborne charges maybe 5 miles distant. A shortest electrical connection may be three miles down to earth and four miles through earth to those charges. If appliances get in that path, then damage occurs.


Three miles down to earth is reasonable. Another 4 miles through earth is not.
The vast majority of the lightning strike energy will be dissipated close
to where it strkes earth. It's also obviously not about the "shortest"
path, or lightning bolts would just come straight down and there would be
no surge damage anywhere. It's about multiple paths, of varying resistance..



A direct strike to AC wires far down the street is incoming to every household appliance. Now that current must hunt for an outgoing path to earth via some appliances (and to charges maybe four miles away). If that current is connected to earth BEFORE entering a structure, then no destructive hunt exists inside the house.


Sure, if it was theoretically possible in a perfect world to intercept
100% of the surge, then that would be true. But in the real world, it's
not possible. Which is why the IEEE, NIST recommend a tiered strategy
which includes multi-port plug-in surge protectors for PCs, TV, etc.



Best protection for TV cable is a hardwire from cable to single point earth ground. Then a surge need not enter on TV cable.


IEEE says otherwise.


AC electric and phone cannot connect directly to earth. So a 'whole house' protector does what that hardwire does better - connect a surge to earth..

If every wire inside every incoming cable makes a low impedance (ie less than 10 foot) connection to earth, then an incoming and outgoing path (the hunt) need not exist via appliances.


IEEE and NIST say otherwise. Read the guides.



A protector is only a connecting device to what does protection. Protection is a connection to and quality of earthing electrodes at the service entrance.

The questions asked many times, but never answered. A Boeing 777 has
no direct connection to ground, yet it's protected from surges, how is
that possible? If protection is impossible without a direct earth
connection, how can the surge protection which WTom admits is built into
every appliance, work? How can that minimal protection inside an
appliance be effective, yet the plug-in not only can't work, but it causes
damage? BOTH are operating under the same limitation, ie no direct,
short connection to earth.




Every effort to improve earthing and lower impedance (ie shorten that hardwire) increases appliance protection. Then a surge is less likely to blow through protection inside appliances. A surge is less likely to find earth destructive via appliances.


Wooohh Pilgrim. The story is changing. You've said 100 times that
with a surge protector at the panel, it was impossible for a surge
to ever reach an appliance. Now apparently it is possible.


Earthing is how protection was done over 100 years ago. And how it is done in every facility that cannot have damage. Protectors are only connecting devices to what really does protection - single point earth ground.

Earthing is part of a protection strategy, but it's not the whole strategy.
Read the IEEE and NIST guides.

On Tuesday, October 27, 2015 at 9:35:18 AM UTC-7, bud-- wrote:

The newsgroup is too full of trolls, and people who respond to them,
plus political ****.

True that!

On 10/26/2015 2:31 PM, westom wrote:
On Monday, October 26, 2015 at 12:55:46 PM UTC-4, wrote:
When the power comes back on, particularly in those storm situations
where the power never really goes "out" but the lights blink - THAT is
when you get real "surges" - not to confused with the high amperage
high voltage "spikes" created by lightning. They can damage sensitive
electronics over time.

Surge is a subjective term used to describe low voltages, low currents, high voltages,
radio frequency noise, and low voltages.

"Surge" is a well defined term.

That type surge is already made irrelevant by what is inside appliances

Equipment may or may not have surge protection.

No protector claims to or will even discuss this 'surge' that is irrelevant to the topic.

Nonsense.
The IEEE and NIST surge guides both include surges caused by lightning
and say plug-in protectors are effective.
Some plug-in protectors even have protected equipment warranties, which
include lightning created surges.


If inductive loads are creating surges on AC mains, then AC power switching off 120
times a second is also creating surges.

Maybe you haven't heard - AC mains are sine wave. Maybe of AC mains were
square wave....

An example of a surge created by line, and other, inductance is a fault
cleared by a utility fuse in the field. When the fault current is
interrupted the magnetic field created by the fault current collapses
and can create a damaging surge.

Switching of devices inside a home is very unlikely to cause damage.


What happens when that type anomaly occurs? Depends on numbers. Some are so short that no electthat electronics simply power off - then restart. In both cases without any hardware damage.

There can be damage. Probably more likely on power interrupt than restore.


This anomaly could be a problem especially with electronics in the 1950s and 60s when hardware was not as robust.

You think vacuum tubes are sensitive to surges?

On 10/26/2015 5:57 AM, trader_4 wrote:

Welcome back Bud, haven't seen you in a long time. Helping with the
truth here is always appreciated.

The newsgroup is too full of trolls, and people who respond to them,
plus political ****.

On 10/27/2015 9:01 AM, westom wrote:
On Monday, October 26, 2015 at 7:04:19 PM UTC-4, Muggles wrote:
I do understand what you've been saying about earthing. The current has
to have an entry and exit point as it's searching for it's target.

Surges that do damage are hunting for earth ground.

Surges created by normal and abnormal utility operations may be
line-to-line or line-to-neutral.


If that current is connected to earth BEFORE entering a structure, then no
destructive hunt exists inside the house.

A nearby lightning strike may be picked up as a surge with wiring acting
as a "long wire" or "loop" antenna. This is another surge that is not
"hunting for earth ground". Surge protection where wires enter the
building do not provide protection from this.


Best protection for TV cable is a hardwire from cable to single point earth
ground. Then a surge need not enter on TV cable.

Coax protection is normally a "ground block", which allows the coax
shield to be connected to the power earthing system. The IEEE surge
guide says “there is no requirement to limit the voltage developed
between the core and the sheath. .... The only voltage limit is the
breakdown of the F connectors, typically ~2–4 kV.” And "there is
obviously the possibility of damage to TV tuners and cable modems from
the very high voltages that can be developed, especially from nearby
lightning."

Every effort to improve earthing and lower impedance (ie shorten that hardwire)
increases appliance protection.

The author of the NIST guide (Martloff) has written “the impedance of
the grounding system to ‘true earth’ is far less important than the
integrity of the bonding of the various parts of the grounding system.”
In many houses the entry point for cable or phone is too far from the
power service to get effective bonding.

Protection, ultimately, is that the voltage between wires is
non-damaging; that when a surge hits the potential of all wires rises
together.

From westom you get a simple minded belief in earthing, which ignores
messy details, such as above, and is often completely wrong. Westom
hasn't disagreed with any of this, he just ignores it. He ignores
anything that conflicts with his simple-minded beliefs.


Still ignored - answers to simple questions:
- Why do the only 2 detailed examples of protection in the IEEE surge
guide use plug-in protectors?
- Why does the NIST surge guide says plug-in protectors are "the easiest
solution"?
- Why does the NIST surge guide say "One effective solution is to have
the consumer install" a multiport plug-in protector?
- Why does the NIST surge guide say "Plug-in...The easiest of all for
anyone to do. The only question is 'Which to choose?'"
- Why does the IEEE surge guide says for distant entry points "the only
effective way of protecting the equipment is to use a multiport
[plug-in] protector."
- Why does the IEEE surge guide explain how plug-in protectors work -
and it is not primarily by earthing?

For real science read the IEEE and NIST surge guides. Excellent and
reliable information on surge protection. And both say plug-in
protectors are effective.

Then read the sources that agree with westom that plug-in protectors do
NOT work. There are none.