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 leiboldPremium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:6
 ·SONIC.NET
| reply to CajunWon
Re: SPD said by CajunWon:Within the user review of the referenced AZ product listing: connect both the white and green wires to whats called the "common bus" This is correct when the surge protector is installed in a main panel since in a main panel Ground (Green wire) and Neutral (White wire) are bonded together. Even with the bond there may be separate Neutral and Ground bars.
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.
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garys_2kPremium
join:2004-05-07
Farmington, MI Reviews:
 ·callwithus
·Callcentric
| Where would the "best" place to install one of these be if you also had a generator with an ATS: At the house's main panel (downstream from the ATS) or on the incoming service lines in the ATS? Maybe get two?
I'd want to protect the ATS' electronics from a surge, but also get house protection even from a gennie burp. Hmmm, I'm thinking that the best bet would be two surge protectors. | |
leiboldPremium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:6 Reviews:
·SONIC.NET
| said by garys_2k:Hmmm, I'm thinking that the best bet would be two surge protectors. If you only want to install one surge protector I would choose the location with the better path to ground. However it sounds as if in your case two surge protectors are a good idea.
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| reply to leibold
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. | |
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!. | |
| reply to westom
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. | |
| 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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| said by laserfan: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). It looks like a coil, or a loop of wire. The size varies with the installation. One member here has a NEMA box with heavy guage wire coils in it, ahead of his panel. Mine's a coil about 4' diameter, and four turns. A neat installation could implement a large metal enclosure for the coil and mounted on a pedestal outside the residence.
Looking at lightning on a spectrum analyzer, one sees the whole baseline noise level jump about 30dB for distant lightning. It's easy to see how a local strike could be well over 100dB rise in voltage across the 1GHz spectrum.
For multiple buildings you might have them all tap a central earth ground nearest the center of the complex. Copper strapping, buried in concrete, is effective over moderate distances. Use of ordinary wire like Home Depot sells as "ground wire" is ineffective for anything more than static drainoff with a nearby strike. Heavy, and wide, copper strapping has an effectively low impedance at these higher frequencies. It's what we use at broadcast tower sites as ground and towers get hit several times a summer. | |
garys_2kPremium
join:2004-05-07
Farmington, MI | I'd guess that the coils would need to be spread apart a bit to prevent flash-over from the incoming wires to those leaving for the house. Probably would be good to provide a low impedance arc path to ground in that enclosure, too. | |
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