Lightning eats SSA Excom Minutes

On Nov 23, 9:56 am, "w_tom" wrote:

There is no stopping or blocking of lightning as plug-in protector
manufacturers hope you believe.
The best information I have seen on surges and surge protection is at
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf
- the title is "How to protect your house and its contents from
lightning: IEEE guide for surge protection of equipment connected to AC
power and communication circuits" published by the IEEE in 2005 (the
IEEE is the dominant organization of electrical and electronic
engineers in the US).

A second guide is
http://www.nist.gov/public_affairs/p.../surgesfnl.pdf
- this is the "NIST recommended practice guide: Surges Happen!: how to
protect the appliances in your home" published by the National
Institute of Standards and Technology (the US government agency
formerly called the National Bureau of Standards) in 2001

Both guides were intended for wide distribution to the general public
to explain surges and how to protect against them. The IEEE guide was
targeted at people who have some (not much) technical background.

Both say plug-in surge suppressors are effective.

All interconnected devices, like a computer and printer, need to
connect to the same surge protector. If a device, like a computer, has
external connections like phone or LAN, all those wires have to run
through the surge suppressor for protection. This type of suppressor is
called a surge reference equalizer (SRE) by the IEEE (also described by
the NIST). The voltage on all wires connected to the SRE (power, phone,
CATV, LAN, ...) are clamped to a common ground at the SRE and the
voltages are held to a value that is safe to the connected device.
Ratings vary from junk to very high.

While a single point ground with phone, CATV, ... protectors connecting
with short wires to the grounding electrode wire at the power service
is best for eliminating the ground potential differences in Doug's
post, SREs also provide protection.


That protector also does not stop or absorb anything. A protector is
only as effective as its earth ground. Effective protectors make a
short and temporary connection to earth.
As is clearly described in the IEEE guide, plug-in suppressors work by
clamping,.They do not work primarily by earthing, or stopping,
blocking, absorbing.


Many
believe a plug-in protector will somehow stop or absorb what 3 miles of
sky could not.
Among those who believe that are the IEEE and NIST.

--
bud--

Eric Greenwell wrote:
Martin Gregorie wrote:
Mike the Strike wrote:
A severe positive ground flash blew a glider apart in
Britain a few years ago.

That was a K-21. The strike entered at one aileron push rod and
traveled to the other aileron push-rod, where it exited, through the
spanwise alloy push-rods and control linkage.

Ohmic heating in the control linkage produced a strong enough pressure
pulse to cut the fuselage in half and to blow out both canopies. The
skins were blown off both wings as well.

Did the pilots report noticing any sparks, tingling, or other
"electrification" before the strike? I've had lightning strike within a
mile of my glider without noticing any signs of it, before or after.

No, nothing reported by either pilot. Additional support them not being
directly or indirectly affected is that the AAIB report says that only
the aileron control system showed signs of damage from the strike: even
the airbrake system showed no signs of electrical damage and probably
didn't carry any current.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Michael Ash wrote:
To the extent that the surge protector is able, yes. However, the cheap
power strip surge protectors that people often have are unlikely to absorb
a lighting strike. If this is your goal, make sure you purchase one that
says it can handle it. ...

Show me a surge protector with numbers that can 'absorb' or therefore
eliiminate surges? Myth purveyors - those who never looked inside nor
read a manufacturer datasheet - believe a surge protector somehow stops
or absorbs what three miles of sky could not. An appliance connects
directly to AC mains when plugged into a power strip protector. What
is 'in series' to absorb those joules? Nothing. There is no
electrical dam inside that power strip protector. Absorbing is not a
protector function. But with profits so high, myth promoters need you
to make that assumption and hope you ignore those numbers. How many
joules?

They are shunt mode devices. They become conductors only during a
transient - shunting a transient to all other wires. IOW transient now
has even more wires to find earth ground destructively via adjacent
appliances. Yes, adjacent protectors have even contributed to damage
of a powered off appliance. What is the shunt path to earth? Reread
the Carswell story. That transient will seek any path to earth. Give
it a better, non-destructive path; no damage. That is what 'whole
house' protectors and lightning rods accomplish because they provide a
shorter path to earth. Nothing absorbed by protector or lightning rod.

Effective protectors are best located farther from an appliance and
as close to earth ground as is possible ... to shunt to earth. But
again. Show me the numbers. Do you really believe a protector rated
for but hundreds of joules will absorb thousands or millions of joules?

There is no stopping or blocking of lightning as plug-in
protector manufacturers hope you believe. Lightning
damage is made irrelevant by installing a so inexpensive
and properly sized 'whole house' protector on AC mains
where that wire enters the building AND earthed to same
electrode used by telephone and cable TV. Effective
protectors are found in Lowes, Home Depot, and
electrical supply houses using responsible brand names
such as Intermatic, Siemens, Cutler-Hammer, Leviton,
Square D, and GE. Effective protector for a typically
most destructive lightning path costs about $1 per
protected appliance.

That protector also does not stop or absorb anything. A
protector is only as effective as its earth ground.
Effective protectors make a short and temporary
connection to earth.

Cheap power strips include those $150 Monster Cable products sold in
Circuit City. How do you know they are cheap? Where is the dedicated
earthing wire? No earth ground means no effective protection.

somewhere, in some safety bulletin somewhere, or maybe in the soaring
magazine, is a truly FRIGHTENING account by Ken Sorenson when his plane
(while flying) was struck by lightening.....glass and carbon, but you
would be amazed. Ken was flying in a contest at Moriarty when it
happened. He was able to land safely, after the cockpit exploded from
the pressure wave....

I don't think anyone wants to "experiment" like that!

Micki and
Charlie-Lite

w_tom wrote:
Michael Ash wrote:
To the extent that the surge protector is able, yes. However, the cheap
power strip surge protectors that people often have are unlikely to absorb
a lighting strike. If this is your goal, make sure you purchase one that
says it can handle it. ...

Show me a surge protector with numbers that can 'absorb' or therefore
eliiminate surges? Myth purveyors - those who never looked inside nor
read a manufacturer datasheet - believe a surge protector somehow stops
or absorbs what three miles of sky could not. An appliance connects
directly to AC mains when plugged into a power strip protector. What
is 'in series' to absorb those joules? Nothing. There is no
electrical dam inside that power strip protector. Absorbing is not a
protector function. But with profits so high, myth promoters need you
to make that assumption and hope you ignore those numbers. How many
joules?

"Says it can handle it" is more than technical specs. A good attached
equipment guarantee is the best way to say that it can handle a strike.
This gives the manufacturer a good financial incentive to build their
equipment well, and if they fail then they'll pay you for the equipment
lost. Of course they won't recover lost data, but that's why you should
make backups anyway.

--
Michael Ash
Rogue Amoeba Software

Guarantee is obviously so chock full of exemptions as to only convince
the naive. Plug-in protectors do not claim to provide protection. It
provides protection from a typically non-destructive transient. Then
phrase the claim so that naive will assume that is protection from all
types of surges. Same half-truth word games got so many to believe
Saddam had WMDs.

That plug-in protector does not claim to handle anything. Have
doubts? Then put up their numerical specifications for each type of
transient. Little hint. No such numerical claims exist. But then
tobacco companies also successfully promoted claims in 1950s and 1960s
that smoking provided better health. Yes, many also believed those
myths.

Hardware protectors that are effective are those that have that
dedicated earthing wire. Effective solutions also costs tens of times
less money. Plug-in protectors avoid discussion about earthing to sell
grossly profitable and often grossly undersized protectors. They are
good at getting others to strongly endorse myths - as demonstrated in
this thread. Where are the numbers? Not provided because so many know
only using subjective reasoning.

So where are numerical specs that "says it can handle it"? Numbers
don't exist for same reason an American president could proclaim Saddam
had WMDs. No numbers - just subjective claims. Sufficient to have many
promote myths rather than ask some embarrassing questions.

Home protection including appliances has always been about earthing -
as even Ben Franklin demonstrated in 1752.

Michael Ash wrote:
"Says it can handle it" is more than technical specs. A good attached
equipment guarantee is the best way to say that it can handle a strike.
This gives the manufacturer a good financial incentive to build their
equipment well, and if they fail then they'll pay you for the equipment
lost. Of course they won't recover lost data, but that's why you should
make backups anyway.

On Nov 24, 6:19 pm, "w_tom" wrote:

That plug-in protector does not claim to handle anything.
Humor for the day.

Have
doubts? Then put up their numerical specifications for each type of
transient. Little hint. No such numerical claims exist.
A bs argument. You have never provided a link to any site that has the
specs you say are required. If you could look at the nice pictures in
the IEEE guide you could see power wires have MOVs H-N, H-G, N-G -
covering all modes. In addition, common mode surges (H & N lift away
from G) coming in on the power line are converted to transverse mode
surges (H lifts away from N & G) by the N-G bond in US services.


Hardware protectors that are effective are those that have that
dedicated earthing wire.
Your religious views on earthing are not shared by the IEEE or NIST.
Plainly described in the IEEE guide - protection is by clamping, not
earthing.



They are
good at getting others to strongly endorse myths - as demonstrated in
this thread. Where are the numbers? Not provided because so many know
only using subjective reasoning.
I have provided links from the IEEE and NIST that say plug-in surge
suppressors are effective. You have provided your myths and subjective
reasoning.

--
bud--

Check this guy out (click view profile in Google groups)!

He keeps on posting the same answers in different group discussions
that have to do with lightning strikes.

Amateur lightning enthusiast? Industry advocate? Surge protector
vendor?

Who knows...


bud-- wrote:
On Nov 24, 6:19 pm, "w_tom" wrote:

That plug-in protector does not claim to handle anything.
Humor for the day.

Have
doubts? Then put up their numerical specifications for each type of
transient. Little hint. No such numerical claims exist.
A bs argument. You have never provided a link to any site that has the
specs you say are required. If you could look at the nice pictures in
the IEEE guide you could see power wires have MOVs H-N, H-G, N-G -
covering all modes. In addition, common mode surges (H & N lift away
from G) coming in on the power line are converted to transverse mode
surges (H lifts away from N & G) by the N-G bond in US services.


Hardware protectors that are effective are those that have that
dedicated earthing wire.
Your religious views on earthing are not shared by the IEEE or NIST.
Plainly described in the IEEE guide - protection is by clamping, not
earthing.



They are
good at getting others to strongly endorse myths - as demonstrated in
this thread. Where are the numbers? Not provided because so many know
only using subjective reasoning.
I have provided links from the IEEE and NIST that say plug-in surge
suppressors are effective. You have provided your myths and subjective
reasoning.

--
bud--

bud-- wrote:
On Nov 23, 9:56 am, "w_tom" wrote:

There is no stopping or blocking of lightning as plug-in protector
manufacturers hope you believe.
The best information I have seen on surges and surge protection is at
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf
- the title is "How to protect your house and its contents from
lightning: IEEE guide for surge protection of equipment connected to AC
power and communication circuits" published by the IEEE in 2005 (the
IEEE is the dominant organization of electrical and electronic
engineers in the US).

A second guide is
http://www.nist.gov/public_affairs/p.../surgesfnl.pdf
- this is the "NIST recommended practice guide: Surges Happen!: how to
protect the appliances in your home" published by the National
Institute of Standards and Technology (the US government agency
formerly called the National Bureau of Standards) in 2001

Both guides were intended for wide distribution to the general public
to explain surges and how to protect against them. The IEEE guide was
targeted at people who have some (not much) technical background.

Both say plug-in surge suppressors are effective.

All interconnected devices, like a computer and printer, need to
connect to the same surge protector. If a device, like a computer, has
external connections like phone or LAN, all those wires have to run
through the surge suppressor for protection. This type of suppressor is
called a surge reference equalizer (SRE) by the IEEE (also described by
the NIST). The voltage on all wires connected to the SRE (power, phone,
CATV, LAN, ...) are clamped to a common ground at the SRE and the
voltages are held to a value that is safe to the connected device.
Ratings vary from junk to very high.

While a single point ground with phone, CATV, ... protectors connecting
with short wires to the grounding electrode wire at the power service
is best for eliminating the ground potential differences in Doug's
post, SREs also provide protection.


That protector also does not stop or absorb anything. A protector is
only as effective as its earth ground. Effective protectors make a
short and temporary connection to earth.
As is clearly described in the IEEE guide, plug-in suppressors work by
clamping,.They do not work primarily by earthing, or stopping,
blocking, absorbing.


Many
believe a plug-in protector will somehow stop or absorb what 3 miles of
sky could not.
Among those who believe that are the IEEE and NIST.

I suggest that you go back and re-read your references. For instance,
on pg. 38:

Well-designed and well-built plug-in protectors will actually withstand
the
10,000 A (8x20 µs) surge current, and that is rating required by NFPA
780-2004
for plug-in protectors. However, the UL 1449 Standard only requires
plug-in
protectors to withstand, without damage, ~20 500 A surges. Inexpensive
protectors using the 6C type of circuit are designed to respond to
overload by
opening the protective fusing shown in Figure 6C, sometimes at surge
currents
barely over the 500 A limit. Because the UL 500 A surge withstand
requirements
are relatively weak, it is important to have both a hard-wired
protector at the
service entrance and a plug-in protector at the critical loads.

This clearly recommends that you don't depend upon a surge protector
alone, simply because the minimum UL requirements are REALLY a minimum.
Most people don't know that surge protectors use devices (MOVs) that
have a limited life, and they don't have a visible indicator showing
how much of their life is left. High quality surge protectors are sold
by www.zerosurge.com.

The IEEE report confirms what w_tom was saying about voltage
differentials on the building grounding during a lightning strike:

If wiring comes into a building at many different points, it is much
more difficult
to get proper protection against lightning surges. Even if surge
protectors are
installed at these alternate entry points, the long ground wires
running back to the
main building ground greatly reduce the effectiveness of the
protectors. In highlightning
areas, where lightning protection is a major concern, it is worth
routing
as many AC and signal cables as possible past the building power entry
point, to
facilitate good grounding for protectors and cable sheaths

I highly recommend a thorough reading of the IEEE document for a
complete discussion of this issue. The take home message: individual
surge protection devices ARE NOT a complete lightning protection plan.

Tom Seim
Richland, WA

wrote:
bud-- wrote:
On Nov 23, 9:56 am, "w_tom" wrote:

There is no stopping or blocking of lightning as plug-in protector
manufacturers hope you believe.
The best information I have seen on surges and surge protection is at
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf
- the title is "How to protect your house and its contents from
lightning: IEEE guide for surge protection of equipment connected to AC
power and communication circuits" published by the IEEE in 2005 (the
IEEE is the dominant organization of electrical and electronic
engineers in the US).

A second guide is
http://www.nist.gov/public_affairs/p.../surgesfnl.pdf
- this is the "NIST recommended practice guide: Surges Happen!: how to
protect the appliances in your home" published by the National
Institute of Standards and Technology (the US government agency
formerly called the National Bureau of Standards) in 2001

Both guides were intended for wide distribution to the general public
to explain surges and how to protect against them. The IEEE guide was
targeted at people who have some (not much) technical background.

Both say plug-in surge suppressors are effective.

All interconnected devices, like a computer and printer, need to
connect to the same surge protector. If a device, like a computer, has
external connections like phone or LAN, all those wires have to run
through the surge suppressor for protection. This type of suppressor is
called a surge reference equalizer (SRE) by the IEEE (also described by
the NIST). The voltage on all wires connected to the SRE (power, phone,
CATV, LAN, ...) are clamped to a common ground at the SRE and the
voltages are held to a value that is safe to the connected device.
Ratings vary from junk to very high.

While a single point ground with phone, CATV, ... protectors connecting
with short wires to the grounding electrode wire at the power service
is best for eliminating the ground potential differences in Doug's
post, SREs also provide protection.


That protector also does not stop or absorb anything. A protector is
only as effective as its earth ground. Effective protectors make a
short and temporary connection to earth.
As is clearly described in the IEEE guide, plug-in suppressors work by
clamping,.They do not work primarily by earthing, or stopping,
blocking, absorbing.


Many
believe a plug-in protector will somehow stop or absorb what 3 miles of
sky could not.
Among those who believe that are the IEEE and NIST.

I suggest that you go back and re-read your references. For instance,
on pg. 38:

Well-designed and well-built plug-in protectors will actually withstand
the
10,000 A (8x20 µs) surge current, and that is rating required by NFPA
780-2004
for plug-in protectors. However, the UL 1449 Standard only requires
plug-in
protectors to withstand, without damage, ~20 500 A surges. Inexpensive
protectors using the 6C type of circuit are designed to respond to
overload by
opening the protective fusing shown in Figure 6C, sometimes at surge
currents
barely over the 500 A limit. Because the UL 500 A surge withstand
requirements
are relatively weak, it is important to have both a hard-wired
protector at the
service entrance and a plug-in protector at the critical loads.

This clearly recommends that you don't depend upon a surge protector
alone, simply because the minimum UL requirements are REALLY a minimum.
Most people don't know that surge protectors use devices (MOVs) that
have a limited life, and they don't have a visible indicator showing
how much of their life is left. High quality surge protectors are sold
by www.zerosurge.com.

The IEEE report confirms what w_tom was saying about voltage
differentials on the building grounding during a lightning strike:

If wiring comes into a building at many different points, it is much
more difficult
to get proper protection against lightning surges. Even if surge
protectors are
installed at these alternate entry points, the long ground wires
running back to the
main building ground greatly reduce the effectiveness of the
protectors. In highlightning
areas, where lightning protection is a major concern, it is worth
routing
as many AC and signal cables as possible past the building power entry
point, to
facilitate good grounding for protectors and cable sheaths

I highly recommend a thorough reading of the IEEE document for a
complete discussion of this issue. The take home message: individual
surge protection devices ARE NOT a complete lightning protection plan.

Tom Seim
Richland, WA
Many surge protectors 'wear out' in about five years on our local power
grid. Some of the very old models (those with reset buttons) often
simply stay on permanently, offering no protection at all. Others will
no longer reset (by disconnecting/reconnecting at the outlet). It does
show that they are doing their job, but they are consumed in the
process.

Frank Whiteley