| Indoor Ethernet surge protection? Hello all. Recent storm rolled through my area and caused some problems. No outdoor equipment actually got struck, so that is good (not exactly sure where the spikes came from). My problem is a few onboard ethernet jacks got fried as well as a few routers.
Can anyone out there recommend some type of indoor cat5 surge protection? I have seen some on Ebay that are go-betweens and ground on an AC outlet (do they work?)
Thanks. |
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| what about putting a poe protector at the building entrance? |
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lutfulPremium
join:2005-06-16
Ottawa, ON Reviews:
 ·TekSavvy DSL
2 edits | reply to jakkwb
said by jakkwb:a few onboard ethernet jacks got fried as well as a few routers ... recommend some type of indoor cat5 surge protection Ethernet surge protectors being sold at many WISP online stores for outdoor usage are actually more suitable for typical indoor surges.
Always check datasheet for the clamping voltage on Ethernet data pairs - a lower voltage rating (6V or 7.5V is OK) will protect more sensitive equipment. 
*** I recall seeing above protector at many sites - maybe without CITEL logo - it will be fine. You can hook up the grounding wire to AC ground. |
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public
join:2002-01-19
Santa Clara, CA | said by lutful:Always check datasheet for the clamping voltage on Ethernet data pairs - a lower voltage rating (6V or 7.5V is OK) will protect more sensitive equipment. While differential clamping is desirable damage is usually due to common mode surge. Good protector should have gas tubes for pair to ground and pair to pair protection.
Transtector seems to work well
»www.transtector.com/admin/DataSh···-624.pdf |
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robbinPremium,MVM
join:2000-09-21
Leander, TX
kudos:1 | reply to lutful
said by lutful:You can hook up the grounding wire to AC ground. Would that be to code? |
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WHT
join:2010-03-26
kudos:3 | said by robbin:Would that be to code? Literally asked, yes. Because the purpose of that protector was never meant to satisfy any code recommendations, therefore any code would not apply. |
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robbinPremium,MVM
join:2000-09-21
Leander, TX
kudos:1 | Is it UL listed? |
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WHT
join:2010-03-26
kudos:3 | I kinda sorta have an idea where yer going with that, but it meets UL 479b for transient protection. |
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lutfulPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
| reply to public
said by public:damage is usually due to common mode surge. Good protector should have gas tubes for pair to ground and pair to pair protection I agree completely as long as they use appropriate devices for Ethernet specification.
I like to look at internal schematic (which should always be provided) and this particular Transtector design is superb. Thank you for providing the suggestion. |
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2 edits | reply to jakkwb
said by jakkwb:Hello all. Recent storm rolled through my area and caused some problems. ... My problem is a few onboard ethernet jacks got fried as well as a few routers. Can anyone out there recommend some type of indoor cat5 surge protection? As public noted, a surge must be connected short to earth ground. Not safety (receptacle) ground, motherboard ground, a floating ground, or any other ground. Critical to protection is a connection to single point earth ground. Public also says why.
You had damage because the surge was permitted inside the building. Then you assumed surge was incoming on ethernet ports only because they were damaged? Too many erroneous assumptions.
A surge is electricity. That means an incoming and a completely different outgoing path must exist. First the current flows through everything in that path from cloud to earth. Later, something in that path fails. The Ethernet port is one path. What is the other path? No other path means no damage.
You know the Ethernet port was damaged because it was part of a path from cloud to earth. And you know damage existed because energy was permitted inside the building. Protection is always about where energy dissipates. Always. Either you connect that energy harmlessly to earth outside the building. Or that energy is inside hunting for earth destructively via appliances. Once that energy is inside, then nothing will stop or block it. And that is what that Ethernet protector does. Make the always required short (ie 'less than 10 foot') connection to single point earth ground. Earth that current so that it is not inside the building.
Protection is always about where energy dissipates. Single point earth ground is essential. No protector provides protection. Protectors only connect to what provides protection; or do nothing. Single point ground is where energy dissipates harmlessly. Once inside the building, the surge hunts for earth destructively via appliances. Ie current blows through Ethernet ports designed to withstand many thousands of volts.
Clamping voltages is irrelevant if that voltage is not between each ethernet wire and earth ground. For example, if connected to wall receptacle ground, then a 300 volts clamping voltage simply means one side of the protector is 5000 volts; other side is 4700 volts. Ineffective protection when not connected short to earth ground.
Every wire entering a building must be earthed - either directly (ie cable TV, satellite dish) without a protector. Or via a protector (AC electric, telephone). Otherwise energy drives current to earth destructively via appliances. To make that Transtector effective, its ground stud must connect short to single point earth ground. |
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 John GaltForward, MarchPremium
join:2004-09-30
Happy Camp
kudos:3 | reply to jakkwb
Surge protection and suppression requires a multi-faceted approach to effective.
You cannot put a single device in one location within your system and expect it to be protected.
--
Remember, Tuesday is Soylent Green Day.
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lutfulPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
1 edit | reply to westom
said by westom:surge must be connected short to earth ground. Not safety (receptacle) ground, motherboard ground, a floating ground, or any other ground. Critical to protection is a connection to single point earth ground. I think you are confused about indoor surge protection of telecom/datacom equipment. Please check relevant standards and recommendations against your "absolute" assertions.
FYI most indoor telecom/datacom equipment are actually ungrounded as they use 2-prong AC or DC from adapter and thankfully global standards allow them to be fully protected against typical indoor surges without "earth" grounding. Data lines of other indoor equipment can be surge protected via the 3-prong AC plug/socket. See above diagrams for equipment with ring/tip interface. |
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3 edits | FYI most indoor telecom/datacom equipment are actually ungrounded as they use 2-prong AC or DC from adapter and thankfully global standards allow them to be fully protected against typical indoor surges without "earth" grounding.
Nobody said anything about appliance 'safety' ground. Safety (wall receptacle) ground is not earth ground. Even the code has an expression for that ground that is not earth ground - "equipment ground".
Telcos everywhere in the world locate the protector within feet of earth ground. And up to 50 meters distant from electronics. Their switching centers suffer at least 100 surges with each thunderstorm. Damage means no telephone service in town for four days. So telcos install no protectors at the electronics. Earth every wire where it enters the building with a protector as close as possible to earth ground. And, to increase protection, put that protector up to 50 meters distant from electronics. Separation is important for effective protection.
All appliances contain significant surge protection. Anything that might work on its power cord is already inside appliances. Some (ie computers) have even better internal protection as even required by Intel ATX standards.
The surge that overwhelms internal protection seeks earth ground. Either that surge is harmlessly absorbed outside the building. Or it will go hunting; overwhelm protection inside an appliance. Facilities that must never have damage always locate the protector within feet of single point earth ground at the service entrance. Wall receptacle safety ground is not relevant and does not provide earthing. |
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lutfulPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
2 edits | said by westom:Telcos everywhere in the world locate the protector within feet of earth ground. And up to 50 meters distant from electronics. How about doing it outdoors near the building entry point? Check my recent thread which shows best practice for WISP CPEs using annotated diagrams from Alvarion and Motorola. »Best practice generalized from Motorola/Alvarion docs
Anyway I was actually discussing supplemental indoor surge protection because of the title of this thread.
You will find something like this in career grade indoor equipment - IEC/EN61000 is the global standard. From typical Cisco datasheet:
IEC/EN61000-4-5 Surge AC Port (4-kV CM, 2-kV DM)
IEC/EN61000-4-5 Surge Signal Port (1-kV indoor, 2-kV outdoor)
IEC/EN61000-4-5 Surge DC Port (1 kV)
All surges (AC, DC, signal) are diverted to "real ground" through the standard 3-prong socket of compliant equipment. Equipment grounding (which is extra cost option for Cisco) connects to metal chassis to satisfy AC safety rules in some situations. It is not used for IEC/EN61000 compliance. |
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1 edit | said by lutful: All surges (AC, DC, signal) are diverted to "real ground" through the standard 3-prong socket of compliant equipment. All equipment already contains surge protection inside the equipment. Whereas the safety ground prong is necessary for some transients, it is not effective (too far, excessive wire impedance) for typically destructive transients.
So that protection inside all electronics (industrial or home) is not overwhelmed, the typically destructive surge is always earthed before it can enter the building. Otherwise that 1000 and 2000 volt protection found in appliances can be overwhelmed. (1970s equipment only met a 600 volt standard.)
Surge protection is about earthing energy outside the building so that protection inside every appliance (even dimmer switches and GFCIs) is not overwhelmed. So telcos earth their protectors up to 50 meters distance from those electronics. That separation increases protection.
Why does every incoming wire go underground? Not connect to the building? First every wire in every cable must be earthed by a 'whole house' type protector in an underground vault. Only then can the wire enter the CO. So that 1000 volt and 2000 volts protection routinely found (for example) in an Ethernet router is not overwhelmed. |
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lutfulPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
| said by westom:every wire in every cable must be earthed by a 'whole house' type protector ... So that 1000 volt and 2000 volts protection routinely found (for example) in an Ethernet router is not overwhelmed. You are arguing with a forum member who has consistently suggested proper lighning surge protection before RF/coax/CAT5 cables enter a building.
Keeping in mind that petty arguments usually lead to prolonged debates and even personal attacks, you can check out these recent discussions and search older threads using common terms ...
»Lightning damage pics
»grounding gurus? comments please (pics attached)
»[Fundamentals] concept of lightning protection zones (LPZ)
»proper lightning surge protection of electrical panels
Meanwhile just assume that CAT5 conductors are not capable of carrying full lightning surge into a building to stay on topic of indoor surge protectors. |
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1 edit | said by lutful:Meanwhile just assume that CAT5 conductors are not capable of carrying full lightning surge into a building to stay on topic of indoor surge protectors. This is completely on topic - indoor surge protectors. Those protectors are ineffective. At best, can only do supplemental protection if the 'whole house' protector is properly earthed. Do virtually nothing if earthed 'whole house' protection does not exist. You provided four URLs that confirm that concept.
Meanwhile a three prong AC plug has no relevance to anything in this discussion. Safety ground Is not relevant to surge protection.
How much surge current can an 18 AWG (lamp cord) wire carry? Up to 60,000 amps. Each network wire would be something approaching 10,000 amps. Higher currents can flow - but that would also melt the wire. Still, an ethernet wire surge must be earthed before entering the building. Those numbers say so. No indoor solution exists. At best, an indoor solution can only supplement protection. Do nothing effective if a 'whole house' protector is not properly earthed. |
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WHT
join:2010-03-26
kudos:3 | said by westom:Still, an ethernet wire surge must be earthed before entering the building. Personally I would agree with you simply because I would be more comfortable keeping the damaging current outside in the first place.
But as far as electrical codes go, the point of bonding to ground can be inside, nothing says it must be done outside first. That is covered in the National Electric code. |
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| said by WHT: But as far as electrical codes go, the point of bonding to ground can be inside, nothing says it must be done outside first. That is covered in the National Electric code. National Electrical code is only for human safety. Earthing must exceed NEC requirements for transistor safety.
Yes, if the concepts are well understood and carefully implemented, then earthing inside a building can be effective. Of course the building's design must be modified. That is Protection 300. This is only Protection 101. How to implement this solution in any home - without changing a building's construction.
Protection means both meeting and exceeding code. NEC requirements alone are not sufficient for effective surge protection. Code is structured to make upgrade for surge protection easy. |
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lutfulPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
| reply to westom
said by westom:indoor surge protectors. Those protectors are ineffective. NEC/UL testing methodology of indoor surge protectors are actually designed to showcase their effectiveness.
said by westom:At best, can only do supplemental protection if the 'whole house' protector is properly earthed. Do virtually nothing if earthed 'whole house' protection does not exist. I will encourage you to check how SPDs are used in various LPZs in above diagram after re-reading the "concept of lightning protection zones" thread listed earlier which shows a whole house with all 3 types of SPDs protecting equipment in all 3 LPZ. BTW using terms like "earthing" is actually a dead giveaway about true understanding of lightning surge protection.
said by westom:a three prong AC plug has no relevance to anything in this discussion. Safety ground Is not relevant to surge protection. Check above diagram of how LPZ3 surge protectors are supposed to divert surge via "primary earth" or PE which becomes ground of IEC 3-prong single phase AC socket.
I highlighted an incoming surge on a phase conductor using red and outgoing surge using green color. You will notice that surge current will always splits up to follow each unique path.
*** Getting back to Ethernet surge protectors, outdoor protector must use very robust GDTs to handle kilovolt/kiloamp surge. They "let through" as much as 30V to 90V indoors which must be handled by an indoor surge protector since many switch/router/SBC Ethernet ports can only handle low voltage on data lines. Even if there is no outdoor protector, the indoor protector will still provide protection against induced surge from distant lightning. Without indoor protector, you will lose equipment much more often. |
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