Re: Daisy chain wireless routers

Tim Clark

In article <.clara.net>,
The Natural Philosopher <a@b.c> writes:
> wrote:
>> On 6-Dec-2007, yallcome <.uk> wrote:
>>
>>>> Both the house and
>>>> outbuilding need broadband. Is it possible to set up BT Homehub in the
>>>> house, then run cat5 out to the other building and plug another
>>>> wireless router in?
>>
>> Fine until (from experience) you have a nearby lightning strike.
>> A few mega-amps flowing through ground resistance can
>> produce a substantial voltage difference between buildings,
>> write off the PC's, and most of the networking stuff.
>
[trimmed]
> Frankly a lightning strike is all bets off everywhere.
> Happened to me. ...
> Burn holes in carpets. Sockets blown out of walls..
>
> If your phone comes in on the overheads, its a far more tempting target
> for Mr Thor.
>
> That means kiss your router/modem goodbye, and the motherboard on the PC
> its connected to probably..and after that the current will dance from
> cable to cable..

Also telephone line to telephone line. Which means for every direct hit
there's a lot more who suffer damage short of that full treatment.

Some feel it pointless to attempt any form of lightning protection,
since you'll always lose a face-to-face confrontation with Mr. Thor.
However, that forgets those hundred odd nearby whose equipment might
well survive if properly protected, while their neighbour's equipment is
tuned to certain toast, protected or not.

When my Internet service was via ISDN, a lightning strike a few houses
away knocked out my ISDN NTE, left the router plugged into that intact, but
knocked out 3 of the ports on an 8-port switch plugged into the router.
As I had no protection, I felt myself lucky it didn't do more, and that
some protection might well have stopped such low-level collateral
damage.

I'd find it difficult to properly risk assess how the cat5 to the
outbuilding ranks alongside all the other routes open to lightning at
various different levels (from direct hit to distant tickle).

--
Tim Clark

Tim Clark

In article <.clara.net>,
The Natural Philosopher <a@b.c> writes:
> wrote:
>> On 6-Dec-2007, yallcome <.uk> wrote:
>>
>>>> Both the house and
>>>> outbuilding need broadband. Is it possible to set up BT Homehub in the
>>>> house, then run cat5 out to the other building and plug another
>>>> wireless router in?
>>
>> Fine until (from experience) you have a nearby lightning strike.
>> A few mega-amps flowing through ground resistance can
>> produce a substantial voltage difference between buildings,
>> write off the PC's, and most of the networking stuff.
>
[trimmed]
> Frankly a lightning strike is all bets off everywhere.
> Happened to me. ...
> Burn holes in carpets. Sockets blown out of walls..
>
> If your phone comes in on the overheads, its a far more tempting target
> for Mr Thor.
>
> That means kiss your router/modem goodbye, and the motherboard on the PC
> its connected to probably..and after that the current will dance from
> cable to cable..

Also telephone line to telephone line. Which means for every direct hit
there's a lot more who suffer damage short of that full treatment.

Some feel it pointless to attempt any form of lightning protection,
since you'll always lose a face-to-face confrontation with Mr. Thor.
However, that forgets those hundred odd nearby whose equipment might
well survive if properly protected, while their neighbour's equipment is
tuned to certain toast, protected or not.

When my Internet service was via ISDN, a lightning strike a few houses
away knocked out my ISDN NTE, left the router plugged into that intact, but
knocked out 3 of the ports on an 8-port switch plugged into the router.
As I had no protection, I felt myself lucky it didn't do more, and that
some protection might well have stopped such low-level collateral
damage.

I'd find it difficult to properly risk assess how the cat5 to the
outbuilding ranks alongside all the other routes open to lightning at
various different levels (from direct hit to distant tickle).

--
Tim Clark

Tim Clark

In article <.clara.net>,
The Natural Philosopher <a@b.c> writes:
> wrote:
>> On 6-Dec-2007, yallcome <.uk> wrote:
>>
>>>> Both the house and
>>>> outbuilding need broadband. Is it possible to set up BT Homehub in the
>>>> house, then run cat5 out to the other building and plug another
>>>> wireless router in?
>>
>> Fine until (from experience) you have a nearby lightning strike.
>> A few mega-amps flowing through ground resistance can
>> produce a substantial voltage difference between buildings,
>> write off the PC's, and most of the networking stuff.
>
[trimmed]
> Frankly a lightning strike is all bets off everywhere.
> Happened to me. ...
> Burn holes in carpets. Sockets blown out of walls..
>
> If your phone comes in on the overheads, its a far more tempting target
> for Mr Thor.
>
> That means kiss your router/modem goodbye, and the motherboard on the PC
> its connected to probably..and after that the current will dance from
> cable to cable..

Also telephone line to telephone line. Which means for every direct hit
there's a lot more who suffer damage short of that full treatment.

Some feel it pointless to attempt any form of lightning protection,
since you'll always lose a face-to-face confrontation with Mr. Thor.
However, that forgets those hundred odd nearby whose equipment might
well survive if properly protected, while their neighbour's equipment is
tuned to certain toast, protected or not.

When my Internet service was via ISDN, a lightning strike a few houses
away knocked out my ISDN NTE, left the router plugged into that intact, but
knocked out 3 of the ports on an 8-port switch plugged into the router.
As I had no protection, I felt myself lucky it didn't do more, and that
some protection might well have stopped such low-level collateral
damage.

I'd find it difficult to properly risk assess how the cat5 to the
outbuilding ranks alongside all the other routes open to lightning at
various different levels (from direct hit to distant tickle).

--
Tim Clark

Tim Clark

In article <.clara.net>,
The Natural Philosopher <a@b.c> writes:
> wrote:
>> On 6-Dec-2007, yallcome <.uk> wrote:
>>
>>>> Both the house and
>>>> outbuilding need broadband. Is it possible to set up BT Homehub in the
>>>> house, then run cat5 out to the other building and plug another
>>>> wireless router in?
>>
>> Fine until (from experience) you have a nearby lightning strike.
>> A few mega-amps flowing through ground resistance can
>> produce a substantial voltage difference between buildings,
>> write off the PC's, and most of the networking stuff.
>
[trimmed]
> Frankly a lightning strike is all bets off everywhere.
> Happened to me. ...
> Burn holes in carpets. Sockets blown out of walls..
>
> If your phone comes in on the overheads, its a far more tempting target
> for Mr Thor.
>
> That means kiss your router/modem goodbye, and the motherboard on the PC
> its connected to probably..and after that the current will dance from
> cable to cable..

Also telephone line to telephone line. Which means for every direct hit
there's a lot more who suffer damage short of that full treatment.

Some feel it pointless to attempt any form of lightning protection,
since you'll always lose a face-to-face confrontation with Mr. Thor.
However, that forgets those hundred odd nearby whose equipment might
well survive if properly protected, while their neighbour's equipment is
tuned to certain toast, protected or not.

When my Internet service was via ISDN, a lightning strike a few houses
away knocked out my ISDN NTE, left the router plugged into that intact, but
knocked out 3 of the ports on an 8-port switch plugged into the router.
As I had no protection, I felt myself lucky it didn't do more, and that
some protection might well have stopped such low-level collateral
damage.

I'd find it difficult to properly risk assess how the cat5 to the
outbuilding ranks alongside all the other routes open to lightning at
various different levels (from direct hit to distant tickle).

--
Tim Clark

w_tom

On Dec 6, 3:52 pm, wrote:
> I did say nearby, not a directlightningstrike.
> The nearest estimate (from being the locallightning
> sink, based on several strikes) is that the differential
> between buildings is 80-100V. Some equipment
> may suffer from the electromagnetic pulse acting
> on ground loops.

Meanwhile BT's computers connect to overhead wires everywhere in
town. According the research papers, a telco central office may
suffer about 100 surges during every thunderstorm. So for about 5
days every summer, you are without phone service while BT swaps out
the computer? Of course not. It is routine to suffer direct strikes
and no damage. Same protection makes nearby strikes irrelevant.

But that means every wire entering the building is earthed before it
enters. Every wire is earthed to the same earth ground. That
earthing connection is made directly (hardwired) for coaxial wire. Or
via a surge protector for twisted pair. The protector without such
earthing means surge damage is expected. So facilities that must
never suffer damage learned even 100 years ago what must be made
better for no damage.

The protector is only as effective as its earth ground. Earth
ground (not a protector) determines direct lightning strike
protection. Earthing is why BT can suffer 100 surges - and no
damage. Also essential is to locate the protector distant from
electronics. A protector adjacent to electronics (and too far from
earth ground) may simply earth that surge, destructively, through
electronics.

Telcos prefer protectors to be located up to 50 meters distant from
electronics - and as short as possible to earth ground. For that
building interconnect cable, that means every wire in the cable must
make a less than 3 meter connection to earth where it enters the
building. A connection to the same earth ground electrode used by AC
electric, telephone, cable, and any other incoming wire.

It has long been routine to hook buildings together with wire and
not suffer damage. But many don't learn why. Earthing determines
whether a surge does not enter the building - does not find earth
ground, destructively, through electronic appliances. But again, this
is how its been done for 100 years. This is why BT with computers
connected to overhead wires all over town must never suffer
electronics damage. Protection is not some magic box. Protection is
defined by the earth ground. Earthing (and a protector to connect each
ethernet wire short to earth) means no damage from direct lightning
strikes.

Some protectors made effective by a short connection to earth:

bud--

On Dec 9, 3:03 pm, w_tom <> wrote:
> On Dec 6, 3:52 pm, wrote:
>
> > I did say nearby, not a directlightningstrike.
> > The nearest estimate (from being the locallightning
> > sink, based on several strikes) is that the differential
> > between buildings is 80-100V. Some equipment
> > may suffer from the electromagnetic pulse acting
> > on ground loops.
>
> The protector is only as effective as its earth ground. Earth
> ground (not a protector) determines direct lightning strike
> protection.

It isn't practical to protect against direct lightning strike to a
house - as in the Natural Philosopher post.

For reliable information on surges and surge protection try:

And also:


The IEEE guide is aimed at those with some technical background. The
NIST guide is aimed at the unwashed masses.

System earthing can be a little different in the UK vs US, and
different voltages. Most information is the same.

The IEEE guide explains plug-in suppressors work by CLAMPING the
voltage on all wires (signal and power) to the common ground at the
suppressor. Plug-in suppressors do not work primarily by earthing. The
guide explains earthing occurs elsewhere. (guide starting pdf page
40).

Note that all interconnected equipment needs to be connected to the
same plug-in suppressor, or interconnecting wires need to go through
the suppressor. External connections, like phone, also need to go
through the suppressor. Connecting all wiring through the suppressor
prevents damaging voltages between power and signal wires.

> Protection is not some magic box. Protection is
> defined by the earth ground

Both guides say the "magic box" is effective. But wires entering a
building need protection.

--
bud--

w_tom

On Dec 10, 3:45 am, bud-- <> wrote:
> It isn't practical to protect against direct lightning strike to a
> house - as in the Natural Philosopher post.
>
> For reliable information on surges and surge protection try:
> And also:
>
> The IEEE guide is aimed at those with some technical background. The
> NIST guide is aimed at the unwashed masses.

It is routine to have direct lightning strikes and no damage. But
many listen to Bud who promotes plug-in protectors. Others install
those grossly overpriced and ineffective protectors, suffer damage,
then assume nothing can provide protection.

Bud's citation Page 42 Figure 8 demonstrates a plug-in protector
earthing a surge, 8000 volts destructively, through the adjacent TV.
His citations warn of why plug-in protectors (without earth ground)
can create electronics damage. Instead we ignore myths; listen to
what electrical engineering publications say.

A recent technical discussion for electrical engineers state what is
required for surge protection. Earth ground and short connections to
earth. These front page reports from EE Times on 1 Oct and 8 Oct
2007 don't discuss Bud's products because its title is "Protecting
Electrical Devices from Lightning Transients".



Routine is to have direct lightning strikes without damage. Even
more routine now that standards also require electronics (ie routers)
to withstand many thousands of volts without damage. All electronics
contain internal protection. Any protection that would work adjacent
to electronics is already inside electronics. But that internal
appliance protection may be overwhelmed if a direct lightning strike
is not earthed where wires enter the building. Earth a surge before
it enters the buildingso that internal protection in ALL electronics
is not overwhelmed. EE Times describes technical reality. Solutions
that were proven even 100 years ago are not found in products promoted
by Bud. Solutions can be implemented using products from Furse, et al
- properly earthed protectors.

Those who never learned how to make lightning irrelevant failed to
grasp old, well proven, and standard protection techniques. Using a
magic box that does not even claim to provide protection may result in
damage. So they assume nothing can avoid that damage. The problem: no
earth ground means no effective protection. Plug-in protectors even
connecting surges, destructively, through adjacent electronics. Bud's
magic box solutions don't even claim to provide protection. Ask him
for spec numbers. He remains mute because products he recommends make
no numerical protection claims in specs.

Bud's citations show a protector earthing a surge, destructively,
through a TV because the protector was too close to electronics and
too far from earth ground. Bud's citation is also blunt about what a
protector does: From page 6 (Adobe page 8 of 24) of

> You cannot really suppress a surge altogether, nor
> "arrest" it. What these protective devices do is
> neither suppress nor arrest a surge, but simply
> divert it to ground, where it can do no harm.

No earthing? Then the surge energy must be dissipated elsewhere
such as destructively through household appliances. Protection means
direct strike energy is dissipated in earth - in direct contradiction
to every posted by Bud. What does Electrical Engineering Times
discuss for surge protection? Earthing. Earthing provides the
protection. The effective protector has that 'less than 3 meter'
connection to single point earth ground.

Those who are not myth purveryors (ie EE Times) bluntly state a
surge must be dissipated harmlessly in earth - which is why a
protector is only as effective as its earth ground. Provided were
protectors that have that essential and required earthing connection:





Bud's grossly overpriced products (with massive profit margins)
don't provide that earthing connection. Somehow Bud's myths should be
believed while engineers in EE Times should be ignored? Would you
spend tens or 100 times less money for effective protection from
direct lightning strikes. Responsible manufacturers sell products
that solve the OPs problem - that are similar to what BT installs to
suffer surges and no damage - that have that necessary earthing
connection. No earth ground means no effective protection. Bud's
products do not even claim in specifications to provide protection.

w_tom

On Dec 10, 3:45 am, bud-- <> wrote:
> It isn't practical to protect against direct lightning strike to a
> house - as in the Natural Philosopher post.
>
> For reliable information on surges and surge protection try:
> And also:
>
> The IEEE guide is aimed at those with some technical background. The
> NIST guide is aimed at the unwashed masses.

It is routine to have direct lightning strikes and no damage. But
many listen to Bud who promotes plug-in protectors. Others install
those grossly overpriced and ineffective protectors, suffer damage,
then assume nothing can provide protection.

Bud's citation Page 42 Figure 8 demonstrates a plug-in protector
earthing a surge, 8000 volts destructively, through the adjacent TV.
His citations warn of why plug-in protectors (without earth ground)
can create electronics damage. Instead we ignore myths; listen to
what electrical engineering publications say.

A recent technical discussion for electrical engineers state what is
required for surge protection. Earth ground and short connections to
earth. These front page reports from EE Times on 1 Oct and 8 Oct
2007 don't discuss Bud's products because its title is "Protecting
Electrical Devices from Lightning Transients".



Routine is to have direct lightning strikes without damage. Even
more routine now that standards also require electronics (ie routers)
to withstand many thousands of volts without damage. All electronics
contain internal protection. Any protection that would work adjacent
to electronics is already inside electronics. But that internal
appliance protection may be overwhelmed if a direct lightning strike
is not earthed where wires enter the building. Earth a surge before
it enters the buildingso that internal protection in ALL electronics
is not overwhelmed. EE Times describes technical reality. Solutions
that were proven even 100 years ago are not found in products promoted
by Bud. Solutions can be implemented using products from Furse, et al
- properly earthed protectors.

Those who never learned how to make lightning irrelevant failed to
grasp old, well proven, and standard protection techniques. Using a
magic box that does not even claim to provide protection may result in
damage. So they assume nothing can avoid that damage. The problem: no
earth ground means no effective protection. Plug-in protectors even
connecting surges, destructively, through adjacent electronics. Bud's
magic box solutions don't even claim to provide protection. Ask him
for spec numbers. He remains mute because products he recommends make
no numerical protection claims in specs.

Bud's citations show a protector earthing a surge, destructively,
through a TV because the protector was too close to electronics and
too far from earth ground. Bud's citation is also blunt about what a
protector does: From page 6 (Adobe page 8 of 24) of

> You cannot really suppress a surge altogether, nor
> "arrest" it. What these protective devices do is
> neither suppress nor arrest a surge, but simply
> divert it to ground, where it can do no harm.

No earthing? Then the surge energy must be dissipated elsewhere
such as destructively through household appliances. Protection means
direct strike energy is dissipated in earth - in direct contradiction
to every posted by Bud. What does Electrical Engineering Times
discuss for surge protection? Earthing. Earthing provides the
protection. The effective protector has that 'less than 3 meter'
connection to single point earth ground.

Those who are not myth purveryors (ie EE Times) bluntly state a
surge must be dissipated harmlessly in earth - which is why a
protector is only as effective as its earth ground. Provided were
protectors that have that essential and required earthing connection:





Bud's grossly overpriced products (with massive profit margins)
don't provide that earthing connection. Somehow Bud's myths should be
believed while engineers in EE Times should be ignored? Would you
spend tens or 100 times less money for effective protection from
direct lightning strikes. Responsible manufacturers sell products
that solve the OPs problem - that are similar to what BT installs to
suffer surges and no damage - that have that necessary earthing
connection. No earth ground means no effective protection. Bud's
products do not even claim in specifications to provide protection.

w_tom

On Dec 10, 3:45 am, bud-- <> wrote:
> It isn't practical to protect against direct lightning strike to a
> house - as in the Natural Philosopher post.
>
> For reliable information on surges and surge protection try:
> And also:
>
> The IEEE guide is aimed at those with some technical background. The
> NIST guide is aimed at the unwashed masses.

It is routine to have direct lightning strikes and no damage. But
many listen to Bud who promotes plug-in protectors. Others install
those grossly overpriced and ineffective protectors, suffer damage,
then assume nothing can provide protection.

Bud's citation Page 42 Figure 8 demonstrates a plug-in protector
earthing a surge, 8000 volts destructively, through the adjacent TV.
His citations warn of why plug-in protectors (without earth ground)
can create electronics damage. Instead we ignore myths; listen to
what electrical engineering publications say.

A recent technical discussion for electrical engineers state what is
required for surge protection. Earth ground and short connections to
earth. These front page reports from EE Times on 1 Oct and 8 Oct
2007 don't discuss Bud's products because its title is "Protecting
Electrical Devices from Lightning Transients".



Routine is to have direct lightning strikes without damage. Even
more routine now that standards also require electronics (ie routers)
to withstand many thousands of volts without damage. All electronics
contain internal protection. Any protection that would work adjacent
to electronics is already inside electronics. But that internal
appliance protection may be overwhelmed if a direct lightning strike
is not earthed where wires enter the building. Earth a surge before
it enters the buildingso that internal protection in ALL electronics
is not overwhelmed. EE Times describes technical reality. Solutions
that were proven even 100 years ago are not found in products promoted
by Bud. Solutions can be implemented using products from Furse, et al
- properly earthed protectors.

Those who never learned how to make lightning irrelevant failed to
grasp old, well proven, and standard protection techniques. Using a
magic box that does not even claim to provide protection may result in
damage. So they assume nothing can avoid that damage. The problem: no
earth ground means no effective protection. Plug-in protectors even
connecting surges, destructively, through adjacent electronics. Bud's
magic box solutions don't even claim to provide protection. Ask him
for spec numbers. He remains mute because products he recommends make
no numerical protection claims in specs.

Bud's citations show a protector earthing a surge, destructively,
through a TV because the protector was too close to electronics and
too far from earth ground. Bud's citation is also blunt about what a
protector does: From page 6 (Adobe page 8 of 24) of

> You cannot really suppress a surge altogether, nor
> "arrest" it. What these protective devices do is
> neither suppress nor arrest a surge, but simply
> divert it to ground, where it can do no harm.

No earthing? Then the surge energy must be dissipated elsewhere
such as destructively through household appliances. Protection means
direct strike energy is dissipated in earth - in direct contradiction
to every posted by Bud. What does Electrical Engineering Times
discuss for surge protection? Earthing. Earthing provides the
protection. The effective protector has that 'less than 3 meter'
connection to single point earth ground.

Those who are not myth purveryors (ie EE Times) bluntly state a
surge must be dissipated harmlessly in earth - which is why a
protector is only as effective as its earth ground. Provided were
protectors that have that essential and required earthing connection:





Bud's grossly overpriced products (with massive profit margins)
don't provide that earthing connection. Somehow Bud's myths should be
believed while engineers in EE Times should be ignored? Would you
spend tens or 100 times less money for effective protection from
direct lightning strikes. Responsible manufacturers sell products
that solve the OPs problem - that are similar to what BT installs to
suffer surges and no damage - that have that necessary earthing
connection. No earth ground means no effective protection. Bud's
products do not even claim in specifications to provide protection.

w_tom

On Dec 10, 3:45 am, bud-- <> wrote:
> It isn't practical to protect against direct lightning strike to a
> house - as in the Natural Philosopher post.
>
> For reliable information on surges and surge protection try:
> And also:
>
> The IEEE guide is aimed at those with some technical background. The
> NIST guide is aimed at the unwashed masses.

It is routine to have direct lightning strikes and no damage. But
many listen to Bud who promotes plug-in protectors. Others install
those grossly overpriced and ineffective protectors, suffer damage,
then assume nothing can provide protection.

Bud's citation Page 42 Figure 8 demonstrates a plug-in protector
earthing a surge, 8000 volts destructively, through the adjacent TV.
His citations warn of why plug-in protectors (without earth ground)
can create electronics damage. Instead we ignore myths; listen to
what electrical engineering publications say.

A recent technical discussion for electrical engineers state what is
required for surge protection. Earth ground and short connections to
earth. These front page reports from EE Times on 1 Oct and 8 Oct
2007 don't discuss Bud's products because its title is "Protecting
Electrical Devices from Lightning Transients".



Routine is to have direct lightning strikes without damage. Even
more routine now that standards also require electronics (ie routers)
to withstand many thousands of volts without damage. All electronics
contain internal protection. Any protection that would work adjacent
to electronics is already inside electronics. But that internal
appliance protection may be overwhelmed if a direct lightning strike
is not earthed where wires enter the building. Earth a surge before
it enters the buildingso that internal protection in ALL electronics
is not overwhelmed. EE Times describes technical reality. Solutions
that were proven even 100 years ago are not found in products promoted
by Bud. Solutions can be implemented using products from Furse, et al
- properly earthed protectors.

Those who never learned how to make lightning irrelevant failed to
grasp old, well proven, and standard protection techniques. Using a
magic box that does not even claim to provide protection may result in
damage. So they assume nothing can avoid that damage. The problem: no
earth ground means no effective protection. Plug-in protectors even
connecting surges, destructively, through adjacent electronics. Bud's
magic box solutions don't even claim to provide protection. Ask him
for spec numbers. He remains mute because products he recommends make
no numerical protection claims in specs.

Bud's citations show a protector earthing a surge, destructively,
through a TV because the protector was too close to electronics and
too far from earth ground. Bud's citation is also blunt about what a
protector does: From page 6 (Adobe page 8 of 24) of

> You cannot really suppress a surge altogether, nor
> "arrest" it. What these protective devices do is
> neither suppress nor arrest a surge, but simply
> divert it to ground, where it can do no harm.

No earthing? Then the surge energy must be dissipated elsewhere
such as destructively through household appliances. Protection means
direct strike energy is dissipated in earth - in direct contradiction
to every posted by Bud. What does Electrical Engineering Times
discuss for surge protection? Earthing. Earthing provides the
protection. The effective protector has that 'less than 3 meter'
connection to single point earth ground.

Those who are not myth purveryors (ie EE Times) bluntly state a
surge must be dissipated harmlessly in earth - which is why a
protector is only as effective as its earth ground. Provided were
protectors that have that essential and required earthing connection:





Bud's grossly overpriced products (with massive profit margins)
don't provide that earthing connection. Somehow Bud's myths should be
believed while engineers in EE Times should be ignored? Would you
spend tens or 100 times less money for effective protection from
direct lightning strikes. Responsible manufacturers sell products
that solve the OPs problem - that are similar to what BT installs to
suffer surges and no damage - that have that necessary earthing
connection. No earth ground means no effective protection. Bud's
products do not even claim in specifications to provide protection.