Dealing with Lightning

For a POE Bridge device on a 10 foot mast, anyone have good ideas for a
home-made lightning arrester-ones I've seen advertised seem awfully
expensive for what should be a simple device. Mostly, I am concerned
about damage to my computer and to the house. The ones I have seen
advertised are way too expensive, imo. Will a straight wire from top of
mast to good ground be a step in the right direction? How do I ground
the POE? I am not THAT about the radio being killed as I am about my
computer, house. What's a positive ground?
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On 22 Jun 2006 04:33:11 +0800, LittleJohn <(E-Mail Removed)>
wrote:

>For a POE Bridge device on a 10 foot mast, anyone have good ideas for a
>home-made lightning arrester-ones I've seen advertised seem awfully
>expensive for what should be a simple device. Mostly, I am concerned
>about damage to my computer and to the house. The ones I have seen
>advertised are way too expensive, imo. Will a straight wire from top of
>mast to good ground be a step in the right direction? How do I ground
>the POE? I am not THAT about the radio being killed as I am about my
>computer, house. What's a positive ground?
>_________________________________________
>Usenet Zone Free Binaries Usenet Server
>More than 140,000 groups
>Unlimited download
>http://www.usenetzone.com to open account
>
For isolated buildings (farm barns, etc.) the best approach is to
place an array of static discharge points high on the building,
or nearby. These sharp static discharge points are connected to a
deep earth ground, such as a 6 foot copper rod like those used
for electrical power system grounds.

The array of static discharge points will "bleed off" the local
static charge that would otherwise entice a lightning strike. The
result is the building or whatever doesn't take a protected hit.
It just never gets hit at all.

Gordon

LittleJohn wrote:
> For a POE Bridge device on a 10 foot mast, anyone have good ideas for a
> home-made lightning arrester-ones I've seen advertised seem awfully
> expensive for what should be a simple device. Mostly, I am concerned
> about damage to my computer and to the house. The ones I have seen
> advertised are way too expensive, imo. Will a straight wire from top of
> mast to good ground be a step in the right direction? How do I ground
> the POE? I am not THAT about the radio being killed as I am about my
> computer, house. What's a positive ground?

I think you'll find that for every POE device owner, there'll be a
different opinion on this. Some devices claim to have lightning
protection built in (whatever that means) and some have a Phasar
lightning suppressor between the device and the antenna. I've had very
good luck with an access point at a location that seems to be rich in
lightning strikes. With a Phasar lightning suppressor installed and
grounded to a copper rod driven into the ground, I've only had to
replace it once in about three years. At another location that's even
higher up and more open (on a steel tower), I've got the same history.
Had to replace everything once in the last three years.

Rôgêr <(E-Mail Removed)> wrote:

>I think you'll find that for every POE device owner, there'll be a
>different opinion on this. Some devices claim to have lightning
>protection built in (whatever that means) and some have a Phasar
>lightning suppressor between the device and the antenna. I've had very
>good luck with an access point at a location that seems to be rich in
>lightning strikes. With a Phasar lightning suppressor installed and
>grounded to a copper rod driven into the ground, I've only had to
>replace it once in about three years. At another location that's even
>higher up and more open (on a steel tower), I've got the same history.
>Had to replace everything once in the last three years.

No lightning protection will protect against a direct strike, or a nearby strike
that's carried over the antenna or power lines. The most you can do is try to
minimize the differences in voltage due to surges or distant strikes (ie the
grounding of the chassis or antenna), and to put up lightning protection (ie
rods) to minimize the air/earth potential in the immediate vicinity...

Gordon wrote:
> For isolated buildings (farm barns, etc.) the best approach is to
> place an array of static discharge points high on the building,
> or nearby. These sharp static discharge points are connected to a
> deep earth ground, such as a 6 foot copper rod like those used
> for electrical power system grounds.
>
> The array of static discharge points will "bleed off" the local
> static charge that would otherwise entice a lightning strike. The
> result is the building or whatever doesn't take a protected hit.
> It just never gets hit at all.

Recommended above is ESE (Early Streamer Emmission) technology that
was rejected by the National Fire Protection Association (authors of
the National Electrical Code).
http://www.nfpa.org/assets/files/PDF/700Minutes.pdf
(see PDF page 18+) 00-60 D#00-22 starting with mention of
Heary Brothers Lightning Protection Company, Inc., Bryan
Panel Report follows:
> The proponents of that technology, primarily those associated
> with the Heary Brothers Lightning Protection Company, Inc., ...
> have extolled the technology and, in particular, have claimed
> that ESE terminals offer a vastly increased zone of protection
> over that of traditional lightning rods. Those claims have been
> disputed and, most recently, a special panel created to
> consider information and to issue a report concerning ESE
> lightning protection technology to the Standards Council (Bryan
> Panel Report), firmly rebutted the claims of ESE proponents that
> the technology had been adequately validated, concluding, among
> other things, as follows:
> The ESE lightning protection technology as currently developed
> in the installation of complete systems does not appear to be
> scientifically and technically sound in relation to the claimed
> areas of protection or the essentials of the grounding system
> ...
> given the lack of validation of the primary claims made for the
> ESE technology, renewed standards development activities for
> ESE systems was not appropriate.

Also Dissipation Arrays and pipe cleaners, do they work?:
http://www.polyphaser.com/ppc_TD1020.aspx

On 22 Jun 2006 00:06:55 -0700, "w_tom" <(E-Mail Removed)> wrote:

>Gordon wrote:
>> For isolated buildings (farm barns, etc.) the best approach is to
>> place an array of static discharge points high on the building,
>> or nearby. These sharp static discharge points are connected to a
>> deep earth ground, such as a 6 foot copper rod like those used
>> for electrical power system grounds.
>>
>> The array of static discharge points will "bleed off" the local
>> static charge that would otherwise entice a lightning strike. The
>> result is the building or whatever doesn't take a protected hit.
>> It just never gets hit at all.
>
> Recommended above is ESE (Early Streamer Emmission) technology that
>was rejected by the National Fire Protection Association (authors of
>the National Electrical Code).
>http://www.nfpa.org/assets/files/PDF/700Minutes.pdf
>(see PDF page 18+) 00-60 D#00-22 starting with mention of
>Heary Brothers Lightning Protection Company, Inc., Bryan
>Panel Report follows:
>> The proponents of that technology, primarily those associated
>> with the Heary Brothers Lightning Protection Company, Inc., ...
>> have extolled the technology and, in particular, have claimed
>> that ESE terminals offer a vastly increased zone of protection
>> over that of traditional lightning rods. Those claims have been
>> disputed and, most recently, a special panel created to
>> consider information and to issue a report concerning ESE
>> lightning protection technology to the Standards Council (Bryan
>> Panel Report), firmly rebutted the claims of ESE proponents that
>> the technology had been adequately validated, concluding, among
>> other things, as follows:
>> The ESE lightning protection technology as currently developed
>> in the installation of complete systems does not appear to be
>> scientifically and technically sound in relation to the claimed
>> areas of protection or the essentials of the grounding system
>> ...
>> given the lack of validation of the primary claims made for the
>> ESE technology, renewed standards development activities for
>> ESE systems was not appropriate.
>
> Also Dissipation Arrays and pipe cleaners, do they work?:
> http://www.polyphaser.com/ppc_TD1020.aspx
>
That is indeed an interesting paper, w_tom, but the issue seems
to be arguable. The text at the bottom of page 19 and top of 20
presents that the NFPA technology is no better validated than the
ESE technology.

I was speaking as an observer, not as an expert on the matter. I
grew up in a rural area of northwestern Oklahoma, where
thunderstorms are frequent and sometimes very severe. The use of
conventional lightning rods on rural buildings was a common
practice, but it was an observed fact that lightning did strike
these protective rods quite often. This usually did not produce
any severe damage to the building, but the acoustic explosion
would sometimes rip shingles off the roof.

Those buildings with the needle arrays were never struck, it
seems. I have seen these needle arrays glow, on a dark night,
when a severe thunder storm was settling in over the area, but
this was thought to have been caused by the slow, controlled
dissipation of the local earth charge. The local earth charge
would normally have brought about a lightning strike in the
immediate area, had the local earth charge not been dissipated in
a controlled way.

Gordon

In article <(E-Mail Removed)>,
Clark W. Griswold, Jr. <(E-Mail Removed)> wrote:
>Rôgêr <(E-Mail Removed)> wrote:
>
>>I think you'll find that for every POE device owner, there'll be a
>>different opinion on this. Some devices claim to have lightning
>>protection built in (whatever that means) and some have a Phasar
>>lightning suppressor between the device and the antenna. I've had very
>>good luck with an access point at a location that seems to be rich in
>>lightning strikes. With a Phasar lightning suppressor installed and
>>grounded to a copper rod driven into the ground, I've only had to
>>replace it once in about three years. At another location that's even
>>higher up and more open (on a steel tower), I've got the same history.
>>Had to replace everything once in the last three years.
>
>No lightning protection will protect against a direct strike, or a nearby strike
>that's carried over the antenna or power lines. The most you can do is try to
>minimize the differences in voltage due to surges or distant strikes (ie the
>grounding of the chassis or antenna), and to put up lightning protection (ie
>rods) to minimize the air/earth potential in the immediate vicinity...


What he said.

IMO, you should ground the mast to earth, get a UTP lightning
protector and place it as close to the WiFi box as possible and ground
it to the mast.

Bring the UTP cable into the house and right at the entry point use a
cheap Linksys router between the WiFi gear and your real computers.

Each CAT5 UTP jack is isolated to (ISTR) 4,000 volts so between the
lightning protector at the top of the mast and the linksys box you are
protected pretty well and if you get a really direct hit the Linksys
box will take the hit. They're really cheap.

The ARRL Ham Radio Handbook or several other ARRL publications will
discuss antenna grounding. Your library should have a copy.

http://www.rfparts.com/arrl_hb_2005.html


In addition, I'd get a max-length UTP cable (100 meters) , on the
spool, and use it to connect the entrypoint Linksys to the rest of
your network. The resistance, inductance, and capacitance will soak
up a surge that makes it past the Linksys.

The only thing that will protect you from a direct hit is full backups
stored offsite.



--
a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore. A Proud signature since 2001

> The only thing that will protect you from a direct hit is full backups
> stored offsite.

Or a fiber converter. Go UTP to 100FL and back for the link between the
devices. Just make sure the AC adapters that drive the fiber converters are
also properly shielded and not on the same ground! The added benefit is
that fiber can generally cover much longer distances that UTP.

-Bill Kearney

In article <(E-Mail Removed)> ,
Bill Kearney <(E-Mail Removed)> wrote:
>> The only thing that will protect you from a direct hit is full backups
>> stored offsite.
>
>Or a fiber converter. Go UTP to 100FL and back for the link between the
>devices. Just make sure the AC adapters that drive the fiber converters are
>also properly shielded and not on the same ground! The added benefit is
>that fiber can generally cover much longer distances that UTP.
>
>-Bill Kearney
>


Good suggestion.

What's the cheapest UTP-fibre converter?

It doesn't even have to be faster than 10MB for a long-haul WiFI or
cost-constrained application as they are unlikely to get the speed
advertised on the box.


--
a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore. A Proud signature since 2001

Thanks to all for good answers to my post, more inline...

(E-Mail Removed) (Al Dykes) wrote in news:e7f4h4$q8k$(E-Mail Removed):

> In article <(E-Mail Removed)>,
> Clark W. Griswold, Jr. <(E-Mail Removed)> wrote:
>>Rôgêr <(E-Mail Removed)> wrote:
>>

<snip>

>>
>>No lightning protection will protect against a direct strike, or a
>>nearby strike that's carried over the antenna or power lines. The most
>>you can do is try to minimize the differences in voltage due to surges
>>or distant strikes (ie the grounding of the chassis or antenna), and
>>to put up lightning protection (ie rods) to minimize the air/earth
>>potential in the immediate vicinity...
>
>
> What he said.
>
> IMO, you should ground the mast to earth, get a UTP lightning
> protector and place it as close to the WiFi box as possible and ground
> it to the mast.

I think I need a dummies guide to lightning arrestors. Do you mean an
arrestor device wired in series with the ethernet cable (UTP), and then
grounded to mast? If so, that's only to protect the indoor stuff and why
won't a simple mast to earth ground do all the bleeding off of the
surge, assuming it's a good ground attached to the top of the mast? Do
you have a source or url for example device? Should the mast ground be
connected as high on the mast as possible, with the radio a few feet
below it? Guess I don't understand why a second arrestor is needed if
the mast is grounded to earth at it's top?

>
> Bring the UTP cable into the house and right at the entry point use a
> cheap Linksys router between the WiFi gear and your real computers.

>
> Each CAT5 UTP jack is isolated to (ISTR) 4,000 volts so between the
> lightning protector at the top of the mast and the linksys box you are
> protected pretty well and if you get a really direct hit the Linksys
> box will take the hit. They're really cheap.

Please explain, how can they be isolated if they are connected directly,
don't know what ISTR is. Ethernet cable goes directly from radio to POE
injector,right? If the jacks are connected together, how can they be
isolated?

>
> The ARRL Ham Radio Handbook or several other ARRL publications will
> discuss antenna grounding. Your library should have a copy.
>
> http://www.rfparts.com/arrl_hb_2005.html

I think I've got that solved? Good low (copper solid? gauge?) resistance
wire securely connected to top of mast straight line down to buried
copper rod, correct?

>
>
> In addition, I'd get a max-length UTP cable (100 meters) , on the
> spool, and use it to connect the entrypoint Linksys to the rest of
> your network. The resistance, inductance, and capacitance will soak
> up a surge that makes it past the Linksys.

Your talking again about the cat5 cable (is that universal twisted
pair). 100 meters sounds like a lot, is there no signal depreciation
in that?

>
> The only thing that will protect you from a direct hit is full backups
> stored offsite.
>

Well I will have that. Just don't want to replace my computer hardware
if I can avoid it.
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