 Jack_in_VAPremium
join:2007-11-26
Mathews, VA
kudos:1 | reply to iknow
Re: Surge Protection Residential Whole House said by iknow:said by nunya:I think they all should be bolt-in. I used to like the SQD bolt in stuff, but they went to plastic retainers on the outer rail. All manufacturers went to plastic, but most slide under (BR style). SQD basically have to be "smashed" on.
maybe they are trying to avoid high resistance stab connections!. if you make the connection really tight, it reduces the possibility of high resistance connections. SQD had really nice breakers, they'd trip very quickly on a short, which was uncommon at one time. We've tested Sq D breakers that would not trip until they disintegrated. All circuit breakers should be manually exercised ON/OFF on a regular basis. Especially those in harsh environments.
That's why fuses are a much better and reliable protective device. |
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| reply to leibold
Re: SPD said by leibold:
If the surge protector is installed anywhere else (perhaps protecting a subpanel in a detached structure) you would need to keep White/Neutral and Green/Ground separate.
Please appreciate what a protector does. No protector does protection. A perfect example is the TV cable.
Best protection for cable is a wire, low impedance (ie 'less than 10 feet', no sharp wire bends, not inside metallic conduit, etc) to earth ground. Low impedance is not low resistance. All protection is performed by the earthnig electrode.
Protection is preformed by what absorbs hundreds of thousands of joules. Not the protector. Earth ground. Cable needs no protector. But cable must connect to what does all protection.
'Whole house' protector is effective when it makes that same low impedance connection to single point ground. For example, if a breaker box ground wire goes up over the foundation and down to an electrode, then protection is compromised. That wire must go through the foundation and down to a rod. No sharp bends. Wire shorter. Ground wire routed away from other non-grounding wires. What increases protection? A lower impedance and earthing that exceeds code requirements. Protection is always about where hundreds of thousands of joules dissipate. Always.
A protector must be located so that every utility wire inside every incoming cable makes that low impedance (ie 'less than 10 foot') connection to what does all protection: single point earth ground.
Protectors are simple science. Since lightning may be 20,000 amps, then the protector must be at least 50,000 amps. A protector suffers many direct strikes AND remains functional. That number defines "life expectancy".
"Protection during each surge" is defined by the earthing and its connection. Earthing is the art of protection.
Finally, if a protector's light indicates a failure, then the protector was grossly undersized. That indicator light only reports one type of failure. Meaning a protector greater than 50,000 amps is required for that venue. Properly sized protectors must earth many direct strikes ... and remain functional. |
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iknowPremium
join:2012-03-25 | said by westom:said by leibold:
If the surge protector is installed anywhere else (perhaps protecting a subpanel in a detached structure) you would need to keep White/Neutral and Green/Ground separate.
Please appreciate what a protector does. No protector does protection. A perfect example is the TV cable. Best protection for cable is a wire, low impedance (ie 'less than 10 feet', no sharp wire bends, not inside metallic conduit, etc) to earth ground. Low impedance is not low resistance. All protection is performed by the earthnig electrode. Protection is preformed by what absorbs hundreds of thousands of joules. Not the protector. Earth ground. Cable needs no protector. But cable must connect to what does all protection. 'Whole house' protector is effective when it makes that same low impedance connection to single point ground. For example, if a breaker box ground wire goes up over the foundation and down to an electrode, then protection is compromised. That wire must go through the foundation and down to a rod. No sharp bends. Wire shorter. Ground wire routed away from other non-grounding wires. What increases protection? A lower impedance and earthing that exceeds code requirements. Protection is always about where hundreds of thousands of joules dissipate. Always. A protector must be located so that every utility wire inside every incoming cable makes that low impedance (ie 'less than 10 foot') connection to what does all protection: single point earth ground. Protectors are simple science. Since lightning may be 20,000 amps, then the protector must be at least 50,000 amps. A protector suffers many direct strikes AND remains functional. That number defines "life expectancy". "Protection during each surge" is defined by the earthing and its connection. Earthing is the art of protection. Finally, if a protector's light indicates a failure, then the protector was grossly undersized. That indicator light only reports one type of failure. Meaning a protector greater than 50,000 amps is required for that venue. Properly sized protectors must earth many direct strikes ... and remain functional. you'd be really surprised then at the differential voltage impressed between the center conductor and the shield by lightning!. up in the GHZ range, a high current pulse(lightning) easily destroys cable equipment, IF not protected by a PROPERLY installed protector. common mode voltage is mostly nullified by PROPER grounding of the shield, but don't bet your life on it!. |
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 John GaltForward, MarchPremium
join:2004-09-30
Happy Camp
kudos:5 | reply to CajunWon
Re: Surge Protection Residential Whole House Virtually all residential grounding doesn't even come close to providing protection against lightning. |
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Jack_in_VAPremium
join:2007-11-26
Mathews, VA
kudos:1 | said by John Galt:Virtually all residential grounding doesn't even come close to providing protection against lightning.
Lightning both direct and induced from nearby strikes. |
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 SmokChsrWho let the magic smoke out?Premium
join:2006-03-17
Saint Augustine, FL | reply to CajunWon
From down here in lightning free Florida.. More than likely the whole house surge protector would have done nothing to prevent the damage to your TV.
Some have said your only protection is your earth ground. I don't really agree with that. It's good to have a earth ground, but what is MOST important is to only have ONE ground. When I say that I don't mean that you can only have one ground rod, what I mean is that everything that is or can be a ground is bonded together before it enters the building.
For what I do this is normally done with 3" .032 copper strap. For home applications you will go a long way towards protection with a #6 solid copper wire around the house that ties everything together.
If you live in an area that has underground electric service, then lightning rods for the roof are highly advised as well. |
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 SparkChaserPremium
join:2000-06-06
Downingtown, PA
kudos:3
 ·Verizon FiOS
1 edit | reply to CajunWon
Just got this is the morning email. Thought the forum might appreciate it.
Surge protection—Stop fried electronics
»www.eetimes.com/design/industria···signLine |
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| Nice article, "Surge 101" but I was interested to get to the punch line, which is always "what's this guy selling" and so I looked it up:
»www.bb-elec.com/product_family.a···Trail=94
$100 bucks and applies to only RS22 and 485 lines afaict. Don't sell a three-stage protector for Ethernet it seems. Still, nice info to have. |
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BobAccount deleted
join:2012-07-22
New Jersey | It's also curious, because his voltage levels for RS-232 are wrong. |
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 alkizmo
join:2007-06-25
Pierrefonds, QC
kudos:1 | reply to SmokChsr
said by SmokChsr:but what is MOST important is to only have ONE ground. When I say that I don't mean that you can only have one ground rod, what I mean is that everything that is or can be a ground is bonded together before it enters the building.
That's pretty much the code.
said by SmokChsr:For home applications you will go a long way towards protection with a #6 solid copper wire around the house that ties everything together. Ties everything together? You mean the multiple ground electrodes?
Or are you saying to ground anything that's conductive attached to the house, such as roof antenna, attic venting hoods, drain stacks and so on, to a #6 that goes to your ground rod? |
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| said by alkizmo:Ties everything together? You mean the multiple ground electrodes? A utility demonstrates how to convert defective grounding into a single point ground. And how that earthing should have been done the first time. See figure 2 for good, bad, and ugly grounding:
»www.duke-energy.com/indiana-busi···p-08.asp |
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| reply to westom
Re: SPD One thing often overlooked in the art of protecting against lightning on the mains drop is the fact that it is a high frequency event. The use of inductors to absorb the brunt of the energy, rather than simply trying to shunt 40,000 amperes to ground, is the route I chose in the 1960s. Historically, every summer, our neighbors complain of losing TVs, well pump motors and lights during electrical storms. In 46 years of living at this address, we have had zero problems with these lightning strikes to our branch, while the neighbors are replacing their electronic every summer. The difference is likely the loop of wire, coiled up before it comes into the service panel. We only recently added 'whole house' surge protection, but I'm not sure if it would have helped in our neighbors' cases because there seems to be a fundamental flaw in the design of residential mains drops and grounding systems.
Someone on this group once posted a photo of his panel, showing a similar setup with large coils before the service enters the panel. Obviously, someone who knows what lightning is. Back in the late '40s we used to study it under contract from General Electric, at Immaculate Labs in Stamford, CT. We had the ten million volt generator there, which was quite an experience when we fired the arc. No amount of preparation gets one ready to stand the bang that results. |
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 49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | reply to alkizmo
Re: Surge Protection Residential Whole House said by alkizmo:Ties everything together? You mean the multiple ground electrodes? Yes for example this is a diagram of the grounding at my residence, each service entering the building has its own individual ground rod and those disparate grounds are bonded to the buildings buried ground ring with number six bare copper wire.
This method of grounding and bonding minimizes the chance of a surge travelling through a device connected to two or more services external to the structure.
Or are you saying to ground anything that's conductive attached to the house, such as roof antenna, attic venting hoods, drain stacks and so on, to a #6 that goes to your ground rod?
Wayne
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Madness takes its toll, please have exact change ready… |
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49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | reply to Bob
said by Bob:It's also curious, because his voltage levels for RS-232 are wrong. Hows that??
Wayne
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Madness takes its toll, please have exact change ready… |
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BobAccount deleted
join:2012-07-22
New Jersey Reviews:
 ·Optimum Online
| quote:
These shunting devices are most often installed from each data line to the local earth ground, and should be selected to begin conducting current at a voltage as close as possible above the system's normal communications level. For RS-422 and RS-485 systems, the voltage rating selected is typically 5 - 7 volts, in RS-232 systems 12 - 15 volt devices are appropriate.
The voltage spec for RS-232C is -15V to +15V. So by choosing a MOV in the 12 to 15 V range, you'd be shunting signals within the RS-232C spec.
RS-232C devices are required to withstand connection to any voltage in the -25V to +25V range for an indefinite amount of time. (Yes, you can take an RS-232C output pin at +15V and connect it directly to a -25V power supply and let it run all day without damage!)
So a more appropriate MOV device for RS-232C would be in the 20 to 22 V range, not 12 to 15 V as suggested by the author. |
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| reply to disconnected
Re: SPD said by disconnected :One thing often overlooked in the art of protecting against lightning on the mains drop is the fact that it is a high frequency event. The use of inductors to absorb the brunt of the energy, rather than simply trying to shunt 40,000 amperes to ground, is the route I chose in the 1960s. Historically, every summer, our neighbors complain of losing TVs, well pump motors and lights during electrical storms. In 46 years of living at this address, we have had zero problems with these lightning strikes to our branch, while the neighbors are replacing their electronic every summer. The difference is likely the loop of wire, coiled up before it comes into the service panel. If you already said, I missed it: what does this "coiled-up loop of wire" in advance of the Service Panel look like? Can it be retrofitted into a site?
I completely buy the "high frequency event" statement. At least, an acquaintance of mine, along with having many things in his house fry, did also suffer major electrical damage to his truck with an indirect lightning strike.
As for the "single point ground", the way we are set-up this is really difficult to achieve as our pole and house and garage are 175, 200, and 150 feet apart from one another. We do have a swimming pool, with of course lots of in-ground rebar, and are grounded to *it*--I dunno but maybe this has helped (we've had lots of lightning in 9 years here but no damage to other than trees). |
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Jack_in_VAPremium
join:2007-11-26
Mathews, VA
kudos:1 | reply to 49528867
Re: Surge Protection Residential Whole House said by 49528867:said by alkizmo:Ties everything together? You mean the multiple ground electrodes? Yes for example this is a diagram of the grounding at my residence, each service entering the building has its own individual ground rod and those disparate grounds are bonded to the buildings buried ground ring with number six bare copper wire. This method of grounding and bonding minimizes the chance of a surge travelling through a device connected to two or more services external to the structure. [att=1] Or are you saying to ground anything that's conductive attached to the house, such as roof antenna, attic venting hoods, drain stacks and so on, to a #6 that goes to your ground rod?
That would be a good start. Wayne »www.duke-energy.com/indiana-busi···p-09.asp
Preferred
Depending on the soil multiple ground rods can create potential differences between them causing problems. As the article states telco, catv etc should be tied together and brought to a single point ground with the building ground. Note they do not have multiple ground rods in their article. |
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49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | said by Jack_in_VA:Depending on the soil multiple ground rods can create potential differences between them causing problems. That is incorrect when buried ground ring is in place...
As the article states telco, catv etc should be tied together and brought to a single point ground with the building ground.
Note they do not have multiple ground rods in their article.
For example a basic six foot by twelve foot pad for a remote terminal will have a minimum of four ground rods connected to its buried ground ring and there will be five ground rods if the power pedestal is not installed upon the pad.
Second example would be a cell hut which like an RT pad will have a minimum of four and commonly 6 ground rods connected to its buried ground ring. Then there will be a second but bonded to the first ground ring for the antenna which may have as few as four to as many as a dozen ground rods.
By the way I doubt you will find a single cell site down here in the lightning capitol of the U.S. where the power communications and antenna cable enter through the same header.
Wayne
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Madness takes its toll, please have exact change ready… |
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49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | reply to Bob
Ok that makes sense.
Thanks
Wayne |
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| Where I live it is common to have the "service entrance" on an outdoor pole, and from there to extend underground to multiple buildings and in different directions from the pole, resulting in sub-panels in each building that are hundreds of feet apart from one another. The only ground rod is at the pole itself, meaning afaict that a lightning strike at any one of these buildings, that finds the wiring therein, only finds ground after traversing say 200 feet to the ground rod at the pole.
Conversely, if a surge event occurs in the overhead wiring and gets through the main panel all-the-way to the remote buildings, then even if you have surge protectors, the excess voltage you need to shunt to ground has to go all-the-way out to the pole again.
Do I have this right, and if yes, how can surge protectors work effectively given the distances to ground? I suppose the answer is: I could add ground rods at each of my buildings and then trench/wire these together between each other and the main service pole/ground. Is this ultimately the right way to do it? Is 6ga enough for a 250' distance?
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