Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Jerry Eyers






As everyone else has said, fiber is best, but if that is not an option...

We have had good luck using these:
http://www.hyperlinktech.com/web/hgln_cat6.php

Trancievers will work as well, but that is a more expensive option.
Nothing is going to protect you from a direct strike.

Jerry










Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Robert E . Seastrom


Todd Vierling [EMAIL PROTECTED] writes:

 Seriously, though, that's exactly what you're describing, and about what I'd
 suggest in a no-other-option scenario -- but if it's possible to pull fiber
 through the conduits, it would probably be far less expensive long term, or
 even medium term if the physical fiber spools can be bought cheaply enough.

For those who haven't priced the stuff lately, in spools of 1000' the
per-foot prices of 2-strand MM tight buffered fiber suitable for
pulling in conduits like he (hopefully) has tends to be
price-competitive with cat5 on a per-foot basis.  Extra strands are
cheap; the pricey part of fiber is the jacket and strength members;
even super-pure glass is not that expensive overall.

The expensive parts in the equation turn out to be the termination
trays and connectors.

---Rob




Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Steven M. Bellovin

In message [EMAIL PROTECTED], Robert E.Seastrom writes:


Todd Vierling [EMAIL PROTECTED] writes:

 Seriously, though, that's exactly what you're describing, and about what I'd
 suggest in a no-other-option scenario -- but if it's possible to pull fiber
 through the conduits, it would probably be far less expensive long term, or
 even medium term if the physical fiber spools can be bought cheaply enough.

For those who haven't priced the stuff lately, in spools of 1000' the
per-foot prices of 2-strand MM tight buffered fiber suitable for
pulling in conduits like he (hopefully) has tends to be
price-competitive with cat5 on a per-foot basis.  Extra strands are
cheap; the pricey part of fiber is the jacket and strength members;
even super-pure glass is not that expensive overall.

The expensive parts in the equation turn out to be the termination
trays and connectors.


Also the labor of pulling it, when there's already something in the 
(shudder) ground.

My direct experience with running long-distance underground cable is 
dated -- let's put it like this; we were dealing with RS-232 -- but the 
countermeasures to a direct strike on copper cables don't seem to have 
improved nearly enough...

--Steven M. Bellovin, http://www.cs.columbia.edu/~smb




Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Marshall Eubanks

On Wed, 14 Sep 2005 08:44:16 -0400
 Steven M. Bellovin [EMAIL PROTECTED] wrote:
 
 In message [EMAIL PROTECTED], Robert E.Seastrom writes:
 
 
 Todd Vierling [EMAIL PROTECTED] writes:
 
  Seriously, though, that's exactly what you're describing, and about what 
  I'd
  suggest in a no-other-option scenario -- but if it's possible to pull fiber
  through the conduits, it would probably be far less expensive long term, or
  even medium term if the physical fiber spools can be bought cheaply enough.
 
 For those who haven't priced the stuff lately, in spools of 1000' the
 per-foot prices of 2-strand MM tight buffered fiber suitable for
 pulling in conduits like he (hopefully) has tends to be
 price-competitive with cat5 on a per-foot basis.  Extra strands are
 cheap; the pricey part of fiber is the jacket and strength members;
 even super-pure glass is not that expensive overall.
 
 The expensive parts in the equation turn out to be the termination
 trays and connectors.
 
 
 Also the labor of pulling it, when there's already something in the 
 (shudder) ground.
 
 My direct experience with running long-distance underground cable is 
 dated -- let's put it like this; we were dealing with RS-232 -- but the 
 countermeasures to a direct strike on copper cables don't seem to have 
 improved nearly enough...

I don't think they will... tens of megavolts is hard to protect against.

This depends a little on where you are. I have experience with cable runs  in 
Southern
Florida (where lightning strikes can occur daily), West Virginia and Virginia 
(with strikes common)
and Hawaii (where they don't seem to  be as frequent). The cable may be in the 
ground, but
it is connected to stuff at either end which isn't, and given the potential 
differences that
occur in the natural environment (~ 150 volts per meter of altitude), this 
means that cable runs
can act like lightning rods connected directly to your network gear.

So my jaded perspective is that you WILL get hit if you connect buildings
with copper, and you WILL NOT like it. Since this can be entirely mitigated 
through the use of
fiber, use fiber if you possibly can.

Regards


 
   --Steven M. Bellovin, http://www.cs.columbia.edu/~smb
 
 



Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Steven M. Bellovin

In message [EMAIL PROTECTED], Marshall Eubanks writes:

 
 My direct experience with running long-distance underground cable is 
 dated -- let's put it like this; we were dealing with RS-232 -- but the 
 countermeasures to a direct strike on copper cables don't seem to have 
 improved nearly enough...

I don't think they will... tens of megavolts is hard to protect against.

This depends a little on where you are. I have experience with
cable runs  in Southern Florida (where lightning strikes can occur
daily), West Virginia and Virginia (with strikes common) and Hawaii
(where they don't seem to  be as frequent). The cable may be in
the ground, but it is connected to stuff at either end which isn't,
and given the potential di fferences that occur in the natural
environment (~ 150 volts per meter of altitude), this mea ns that
cable runs can act like lightning rods connected directly to your
network gear.

So my jaded perspective is that you WILL get hit if you connect
buildings with copper, and you WILL NOT like it. Since this can be
entirely mitigated th rough the use of fiber, use fiber if you
possibly can.

Right.  When I lived in North Carolina, there was a ground strike close
to my apartment.  It tripped some circuit breakers, burned out some light
bulbs, and fried the cable TV box, the balun, and the RF input on my TV.

And what regularly happened to our computers and terminal gear in the
CS department was scary.


Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Frank Coluccio

There's not much left to interpretation and preferences here, aside
from the choice of medium to be used. I should also add that some of the
advice that has been posted in this thread, as well-meaning and thoughtful as it
has been, has been downright dangerous to follow.

If one is going to run copper cable between buildings, or outdoors, in
general, in lieu of the better alternatives of fiber or wireless, then
there are local and national electrical, fire and safety codes in effect
that spell out what you must do, enforceable under the penalty of law.
And while certain of those precautions have been spelled out upstream in
piecemeal fashion, none thus far has been entirely accurate or complete.

Yes, when running copper between buildings, lightning arresters/circuit
- i.e., protection - are a must, but they must be placed within a couple
of feet of the building point of entry, or POE. Think about it. Does it
make great sense to protect a cable from surges deep within the interior
of a building if the cable traverses vast distances on premises
unprotected between the point of entry and the terminal point.
Therefore, the stipulation of performing grounding, bonding and surge
protections at the point where the cable enters the building (in
potentially at addition points, elsewhere, when required).

Also, if the copper cable is armored with a corrugated steal jacket,
as many outside plant cables are, then the shielding (the armor) must
also be bonded to earth ground at the POE, as well. So the issue
becomes one not only of grounding, but bonding, as well. And while I'm
on that subject, be aware that many FIBER OPTIC cables designed for
inter-building/outside plant use are also armored and must be treated in
the same manner.

BICSI (Building Industries Consulting Systems International)
www.bicsi.org does a good job of rolling up all of the relevant
standards, as do a number of other sources. For some good coverage of
safety, grounding and bonding principles and techniques see the
following Structured Cabling Supplement reference by Panduit (taken from
the Cisco CCNA Networking Academy Program)

http://www.tecmiami.com/cisco/extra/CCNA1_CS_1_en.pdf 

Frank A. Coluccio
DTI Consulting Inc.
212-587-8150 Office
347-526-6788 Mobile


Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Frank Coluccio

re: what did your electricians say ...

Back to lurking in a moment, but I should note that fire and safety code issues
are so shrouded in matters of locality and jurisdiction, at times, and bound up
in industry and governmental standards that are so esotric in nature, that the
typical electrical worker, and I dare say even most licensed electricians and IT
consultants, are totally unaware of the specifics, or they are given to gross
misconceptions and half-truths. This is so, not so much due to the complex 
nature
of the matter at hand, but due to a lack of regular exposure to it. Nufsed.

Frank A. Coluccio
DTI Consulting Inc.
212-587-8150 Office
347-526-6788 Mobile

On Wed Sep 14 10:58 , 'Hannigan, Martin' sent:



I asked him what did your electricians say and the entire
ground conversation went south.

Good post. Thanks.



--
Martin Hannigan (c) 617-388-2663
VeriSign, Inc. (w) 703-948-7018
Network Engineer IV Operations  Infrastructure
[EMAIL PROTECTED]



 -Original Message-
 From: [EMAIL PROTECTED]
[EMAIL PROTECTED]','','','')[EMAIL PROTECTED] Behalf Of
 Frank Coluccio
 Sent: Wednesday, September 14, 2005 10:52 AM
 To: nanog@merit.edu
 Subject: Re: CAT5 surge/lightning strike protection recommendations?



 There's not much left to interpretation and preferences here, aside

 from the choice of medium to be used. I should also add that
 some of the

 advice that has been posted in this thread, as well-meaning
 and thoughtful as it

 has been, has been downright dangerous to follow.



 If one is going to run copper cable between buildings, or outdoors, in

 general, in lieu of the better alternatives of fiber or wireless, then

 there are local and national electrical, fire and safety
 codes in effect

 that spell out what you must do, enforceable under the penalty of law.

 And while certain of those precautions have been spelled out
 upstream in

 piecemeal fashion, none thus far has been entirely accurate
 or complete.



 Yes, when running copper between buildings, lightning
 arresters/circuit

 - i.e., protection - are a must, but they must be placed
 within a couple

 of feet of the building point of entry, or POE. Think about
 it. Does it

 make great sense to protect a cable from surges deep within
 the interior

 of a building if the cable traverses vast distances on premises

 unprotected between the point of entry and the terminal point.

 Therefore, the stipulation of performing grounding, bonding and surge

 protections at the point where the cable enters the building (in

 potentially at addition points, elsewhere, when required).



 Also, if the copper cable is armored with a corrugated steal jacket,

 as many outside plant cables are, then the shielding (the armor) must

 also be bonded to earth ground at the POE, as well. So the issue

 becomes one not only of grounding, but bonding, as well. And while I'm

 on that subject, be aware that many FIBER OPTIC cables designed for

 inter-building/outside plant use are also armored and must be
 treated in

 the same manner.



 BICSI (Building Industries Consulting Systems International)

 www.bicsi.org does a good job of rolling up all of the relevant

 standards, as do a number of other sources. For some good coverage of

 safety, grounding and bonding principles and techniques see the

 following Structured Cabling Supplement reference by Panduit
 (taken from

 the Cisco CCNA Networking Academy Program)



 http://www.tecmiami.com/cisco/extra/CCNA1_CS_1_en.pdf



 Frank A. Coluccio

 DTI Consulting Inc.

 212-587-8150 Office

 347-526-6788 Mobile


 



Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread David Lesher

Speaking on Deep Background, the Press Secretary whispered:
 
 
 re: what did your electricians say ...
 
 Back to lurking in a moment, but I should note that fire and safety code 
 issues
 are so shrouded in matters of locality and jurisdiction, at times, and bound 
 up
 in industry and governmental standards that are so esotric in nature, that the
 typical electrical worker, and I dare say even most licensed electricians and 
 IT
 consultants, are totally unaware of the specifics, or they are given to gross
 misconceptions and half-truths. This is so, not so much due to the complex 
 nature
 of the matter at hand, but due to a lack of regular exposure to it. Nufsed.


And I shall note that:

Safe

Meets local Code

Works reliably

are often antiparallel terms.




-- 
A host is a host from coast to [EMAIL PROTECTED]
 no one will talk to a host that's close[v].(301) 56-LINUX
Unless the host (that isn't close).pob 1433
is busy, hung or dead20915-1433



Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Bryan Fields

On Tuesday 13 September 2005 03:24 pm, R.P. Aditya wrote:
 Anyone have recommendations (tested/practical is best :-)?
First bond the cable shield to earth at the entry point in both buildings.  
Second use a Tripplite DNET-1 at both buildings.  make sure you have a single 
point ground terminal that everything it bonded to and then that is grounded.

I am in the chicago area, and have towers and locations that have ethernet 
cables running up to radios.  We use this meathod, and don't have problems.  
Worst we had after last night's T-storm was a site with out power :-)

-- 
Bryan Fields
Chief RF Engineer/Partner
illiana.net
219-306-1805


Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Aditya

 On Tue, 13 Sep 2005 20:24:51 +, R.P. Aditya [EMAIL PROTECTED] said:
 I have a bunch of cat5 buried about 1 ft below the surface
 connecting multiple buildings on a campus (short runs) and lightning
 strikes nearby have caused surges along one or more of the cables
 and burnt out switch ports. I would like to protect the switch ports
 -- there seem to be lots of products on the market.

 Anyone have recommendations (tested/practical is best :-)?

 The APC Protectnet PNET1 and PRM24 seem quite nice and not too
 expensive -- if they workpros? cons?

Thanks to everyone who replied on- and off-list.

The installation in question is in a condo development and was done by
licensed electricians and the residents were lead to believe that it
was code compliant. The cat5 cabling is double-sheathed with a
moisture barrier.

As you can well imagine, the residents are very cost-concious. My
preference is that fiber be run in conduits, however even running cat5
in grounded conduit is a big hassle as it will involve cutting across
pavement etc. (I fully appreciate the danger from potential difference
between buildings and copper being a good conducter etc., but I had to
ask a leading question in order to document the problem such that
sufficient notice would be paid by the residents -- I believe I have
that now).

The short-term solution seems to be using the APC PNET1s/Tripplite
DNET1/etc. in each unit and tying them to the water main as an
inexpensive, immediate step while funds are allocated for conduit,
labor etc..

Thanks,
Adi


Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Steven M. Bellovin

In message [EMAIL PROTECTED], Aditya writes:



The short-term solution seems to be using the APC PNET1s/Tripplite
DNET1/etc. in each unit and tying them to the water main as an
inexpensive, immediate step while funds are allocated for conduit,
labor etc..


If I recall correctly, the National Electrical Code was change about a 
dozen years ago to bar grounding to water pipe unless it's within about 
6' of where the pipe enters the house.

--Steven M. Bellovin, http://www.cs.columbia.edu/~smb




Re: CAT5 surge/lightning strike protection recommendations?

2005-09-14 Thread Mark Radabaugh

Steven M. Bellovin wrote:

In message [EMAIL PROTECTED], Aditya writes:
  


  

The short-term solution seems to be using the APC PNET1s/Tripplite
DNET1/etc. in each unit and tying them to the water main as an
inexpensive, immediate step while funds are allocated for conduit,
labor etc..




If I recall correctly, the National Electrical Code was change about a 
dozen years ago to bar grounding to water pipe unless it's within about 
6' of where the pipe enters the house.

   --Steven M. Bellovin, http://www.cs.columbia.edu/~smb
  

The change was in the 1993 NEC and restricts using water pipe as a
ground to being within 5 feet of the point of entrance to the building. 
There is an additional requirement that the water pipe must be metallic
and have a minimum of 10' buried in the ground.   This can be hard to
verify on existing installations due to the common use of plastic water
pipe by utilities in recent years.  The 5' from the point of entrance is
also due to the common use of plastic water pipe in buildings.

-- 
Mark Radabaugh

Amplex
[EMAIL PROTECTED]
419.837.5015



RE: CAT5 surge/lightning strike protection recommendations?

2005-09-13 Thread Wallace Keith

I've had good luck with Oneac products, such as RJELP100. That being
said, it's probably not a good idea to connect switches and/or pc's  in
different buildings with  copper. I'd use fiber between buildings if at
all possible . Differences in ground potential between buildings
(especially during electrical storms) can not only wipe out a switch
port or nic card, but could be lethal to the poor soul with one hand on
a mouse and the other on some nearby grounded object...
Regards,
Keith



-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of
R.P. Aditya
Sent: Tuesday, September 13, 2005 4:25 PM
To: nanog@merit.edu
Subject: CAT5 surge/lightning strike protection recommendations?


I have a bunch of cat5 buried about 1 ft below the surface connecting
multiple buildings on a campus (short runs) and lightning strikes nearby
have caused surges along one or more of the cables and burnt out switch
ports. I would like to protect the switch ports -- there seem to be lots
of products on the market.

Anyone have recommendations (tested/practical is best :-)?

The APC Protectnet PNET1 and PRM24 seem quite nice and not too expensive
-- if they workpros? cons?

Thanks,
Adi


Re: CAT5 surge/lightning strike protection recommendations?

2005-09-13 Thread Jay Hennigan

On Tue, 13 Sep 2005, R.P. Aditya wrote:

 I have a bunch of cat5 buried about 1 ft below the surface connecting multiple
 buildings on a campus (short runs) and lightning strikes nearby have caused
 surges along one or more of the cables and burnt out switch ports.

Don't do that, then.

 I would like to protect the switch ports -- there seem to be lots of
 products on the market.

 Anyone have recommendations (tested/practical is best :-)?

Use the cat5 as a pull rope, install fiber.

 The APC Protectnet PNET1 and PRM24 seem quite nice and not too expensive --
 if they workpros? cons?

Seriously, this is a battle against Mother Nature that you aren't going to
win.  Differences in ground potential as well as induced currents into the
UTP will continue to cause equipment failure as well as possibly kill you
or someone else.

--
Jay Hennigan - CCIE #7880 - Network Administration - [EMAIL PROTECTED]
WestNet:  Connecting you to the planet.  805 884-6323  WB6RDV
NetLojix Communications, Inc.  -  http://www.netlojix.com/


Re: CAT5 surge/lightning strike protection recommendations?

2005-09-13 Thread james edwards

Fiber would be my choice. Not only will it solve the lightening strike
problem; you will not have to worry about
ground potentials being different on each side of the cable run.

James
Routing and Security Administrator
At the Santa Fe Office: Cyber Mesa Telecom
[EMAIL PROTECTED]  [EMAIL PROTECTED]
http://www.cybermesa.com/ContactCM
(505) 795-7101



RE: CAT5 surge/lightning strike protection recommendations?

2005-09-13 Thread Hannigan, Martin


 
 Anyone have recommendations (tested/practical is best :-)?
 
 The APC Protectnet PNET1 and PRM24 seem quite nice and not 
 too expensive --
 if they workpros? cons?


It sounds like you're either out of NEC, or, you are grounding them
to waterpipe. I believe NEC calls for grounding via earth. You 
could strike some rod into the ground several feet deep, attach
to the pipe with conductive screw+locknut+washer, and a proper gauge
for distance cable. Theoretically, that should solve your problem.

What did you electricians say?


-M



Re: CAT5 surge/lightning strike protection recommendations?

2005-09-13 Thread Mark Foster


 I have a bunch of cat5 buried about 1 ft below the surface connecting
 multiple
 buildings on a campus (short runs) and lightning strikes nearby have
 caused
 surges along one or more of the cables and burnt out switch ports. I would
 like to protect the switch ports -- there seem to be lots of products on
 the
 market.

 Anyone have recommendations (tested/practical is best :-)?

 The APC Protectnet PNET1 and PRM24 seem quite nice and not too expensive
 --
 if they workpros? cons?


Adi,

Is there a reason that your between-building runs aren't being done with
Fibre?
It being non-conductive is one immediate advantage

Also if your grounding is inadequate you may like to take a squiz at the
ISO or TIA Standards as they pertain to cabling.
In NZ we have a variety of standards which all point back to ISO, the ANSI
equivalents are TIA/EIA 568-B (Cabling), TIA/EIA-569-A (Pathways and
Spaces) and TIA/EIA-607-A (Electrical Wiring, relevant as it pertains to
Earthing etc).

Even for short runs, If I need to run between buildings externally I won't
even look at copper.

Mark.



Re: CAT5 surge/lightning strike protection recommendations?

2005-09-13 Thread Marshall Eubanks

On Wed, 14 Sep 2005 12:24:39 +1200 (NZST)
 Mark Foster [EMAIL PROTECTED] wrote:
 
 
  I have a bunch of cat5 buried about 1 ft below the surface connecting
  multiple
  buildings on a campus (short runs) and lightning strikes nearby have
  caused
  surges along one or more of the cables and burnt out switch ports. I would
  like to protect the switch ports -- there seem to be lots of products on
  the
  market.
 
  Anyone have recommendations (tested/practical is best :-)?
 
  The APC Protectnet PNET1 and PRM24 seem quite nice and not too expensive
  --
  if they workpros? cons?
 
 
 Adi,
 
 Is there a reason that your between-building runs aren't being done with
 Fibre?
 It being non-conductive is one immediate advantage

I would agree with Mark. Even buried copper can make an
excellent guide for lightning to come right into your equipment, and it can 
only be
isolated so much. (Remember, the electrical  potential of the ground can vary 
over
a cable  run, and will vary if there are elevation changes.) Fiber is the way 
to go.

Regards
Marshall Eubanks


 
 Also if your grounding is inadequate you may like to take a squiz at the
 ISO or TIA Standards as they pertain to cabling.
 In NZ we have a variety of standards which all point back to ISO, the ANSI
 equivalents are TIA/EIA 568-B (Cabling), TIA/EIA-569-A (Pathways and
 Spaces) and TIA/EIA-607-A (Electrical Wiring, relevant as it pertains to
 Earthing etc).
 
 Even for short runs, If I need to run between buildings externally I won't
 even look at copper.
 
 Mark.
 



Re: CAT5 surge/lightning strike protection recommendations?

2005-09-13 Thread Mark Radabaugh

R.P. Aditya wrote:

I have a bunch of cat5 buried about 1 ft below the surface connecting multiple
buildings on a campus (short runs) and lightning strikes nearby have caused
surges along one or more of the cables and burnt out switch ports. I would
like to protect the switch ports -- there seem to be lots of products on the
market.

Anyone have recommendations (tested/practical is best :-)?

The APC Protectnet PNET1 and PRM24 seem quite nice and not too expensive --
if they workpros? cons?

Thanks,
Adi
  

I'll go with the fiber recommendation but that's not what you asked :-)

We use quite a few of the Motorola 300SS surge suppressors.  They are
made for use with Motorola's fixed wireless Internet platform and go on
the Ethernet cable before it enters the building. 

They do a good job of protecting the ports on near misses.  Direct
strikes and they are toast along with anything attached to them - but
that's just the way it goes :-)

http://www.tessco.com/products/headerProductSearch.do?searchType=1searchText=300sssearchField=1

-- 
Mark Radabaugh

Amplex
[EMAIL PROTECTED]
419.837.5015



Re: CAT5 surge/lightning strike protection recommendations?

2005-09-13 Thread David Lesher

Speaking on Deep Background, the Press Secretary whispered:

 
 
 I have a bunch of cat5 buried about 1 ft below the surface connecting multiple
 buildings on a campus (short runs) and lightning strikes nearby have caused
 surges along one or more of the cables and burnt out switch ports. I would
 like to protect the switch ports -- there seem to be lots of products on the
 market.
 
 Anyone have recommendations 

A) Don't.

B) Don't

C)...

Surge protectors can not protect you from ground differential issues.

Your answer is

1) Pull fiber with that CAT5 pullrope.

2) If you REALLY, REALLY can't

Put a fiber transceiver in building A. At least 10 foot away,
put in a 2nd transceiver and connect THAT to the CAT5 going to
building B.  Connect A  B wallwarts to different breakers, with
surge protectorsand stock spares.o

{Extra help; power B from a small hospital-grade isolation
transformer -- low leakage, hi breakdown voltage.}

Hopefully, you'll merely lose transceivers  wallwarts on the
B-side, with nothing in building B being zorched. 




-- 
A host is a host from coast to [EMAIL PROTECTED]
 no one will talk to a host that's close[v].(301) 56-LINUX
Unless the host (that isn't close).pob 1433
is busy, hung or dead20915-1433



Re: CAT5 surge/lightning strike protection recommendations?

2005-09-13 Thread Mark Radabaugh

David Lesher wrote:


Surge protectors can not protect you from ground differential issues.
  

True enough - but 10/100 Ethernet is normally isolated by the
transformer on the Ethernet transceiver.  AFAIK there is not a
connection between the signal lines and ground.  Isolation is 1500V for
the magnetics I checked.

Off course all bets are off when lightning strikes since the voltage
tends to be just a tad higher than 1500 volts.

Mark Radabaugh


Re: CAT5 surge/lightning strike protection recommendations?

2005-09-13 Thread Todd Vierling

On Tue, 13 Sep 2005, David Lesher wrote:

 Put a fiber transceiver in building A. At least 10 foot away,
 put in a 2nd transceiver and connect THAT to the CAT5 going to
 building B.  Connect A  B wallwarts to different breakers, with
 surge protectorsand stock spares.o

That's an amazingly expensive optoisolator.

Seriously, though, that's exactly what you're describing, and about what I'd
suggest in a no-other-option scenario -- but if it's possible to pull fiber
through the conduits, it would probably be far less expensive long term, or
even medium term if the physical fiber spools can be bought cheaply enough.

-- 
-- Todd Vierling [EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED]