Environmental Potentials whole house surge protection, can I get your opinions?
I'd like to protect my whole house from surges rather than use individual units around the house. The power on the NE is pretty good, but I know all it takes one bad zap. Have any of you installed this unit and do you think it works?
Sorry, I was away for a while and missed the fireworks. In any case, my electric was gone over in 2000, the grounding, which was never tested, looks like a submerged rod just outside the house with a clamp holding a thick wire (copper?). Any ideas finding someone on Long Island to do this testing?
Again you ramble on about things completely irrelevant to the OP's questions. Refuse to learn how protection really works. Apparently foolishly assume everything about electricity is defined by the NEC. And repeatedly make adversarial denials with subjective (also called junk science) reasoning.
OP asked about best protection for household appliances. Protection is always about where hundreds of thousands of joules are harmlessly absorbed. A surge that does not enter a building does not hunt for earth destructively via appliances. One item always found and essential for protection is single point earth ground. With a low impedance (not low resistance) connection to earth. Requirements that exceed what is defined by code - that only defines human protection.
Protection is always about where hundreds of thousands of joules are harmlessly absorbed. Always. Another number provided by people who did this stuff. OP's 'whole house' protector is only as effective as its earth ground. Earth grounds that only comply with NEC may even compromise that protection.
Most of what jea48 posts is irrelevant to the OP's requests. Made obvious by subjective claims; without numbers. Made obvious by no grasp of counterpoise, equipotential, impedance, joules and other relevant concepts. And no appreciation of this prime concept: A protector is only as effective as its earth ground. Low impedance earthing makes the OP's 'whole house' protector effective.
You just ramble on and on saying the same things over and over.
As for my posts on this thread I believe I answered all the OP’s questions and concerns accurately. Starting with SPDs and the importance of the integrity of the electrical service’s grounding electrode system/earth connection.
I would ask you to go back to the start of this thread and read my posts, but I know it would be a waste of time. It is obvious you have a problem understanding what you read.
Your understanding of NEC leaves a lot to the imagination.
I know you won’t, but you should at least take the time and read Article 90 of the NEC. It might help you better understand the rest of the book.
Pay close attention to the highlighted last sentence of 90.1 (A)
This Code is not intended as a design specification or an instruction manual for untrained persons.
Then read 90.1(B)
(B) Adequacy. This Code contains provisions that are considered necessary for safety. Compliance therewith and proper maintenance results in an installation that is essentially free from hazard but not necessary efficient, convenient, or adequate for good service or future expansion of electrical use.
Then read the Informational Note just below (B). .
Through out this thread I said the NEC was bare minimum! I repeatedly spoke of the importance of the electrical service grounding electrode system/earth connection. I used IEEE recommendations, not NEC, for the minimum 5 ohm or less grounding electrode to earth resistance. I even said 2 ohms or less was better yet. .
Do NEC codes protect property from *all* hazards - as you have only assumed? Of course not. Codes only protect property from hazards that also threaten human life - such as fire. Appliances can be completely destroyed by other anomalies. NEC says nothing about protecting from those other anomalies. Destroyed appliances that do not threaten human life (ie that do not created a house fire) are ignored by the NEC.
Rather than argue philosophical and broad spectrum concepts, instead learn relevant electrical concepts. OP’s question is clearly about protecting household appliances from surges. Electrical concepts (ignored by NFPA and NEC) such as impedance, counterpoise, equipotenial, and where hundreds of thousands of joules are absorbed - these concepts you also repeatedly ignore. These concepts define protection. Nothing in the NEC discusses these concepts. Because NEC is totally about human protection.
Most critical item for appliance protection is single point earth ground. Earthing that must both **meet** and must **exceed** code requirements. Even measuring earth resistance (to meet human safety requirements) is insufficient.
Protection is always - as in always - about where hundreds of thousands of joules are harmlessly absorbed. A protector is only as effective as its low impedance (ie less than 10 foot) connection to and quality of earth ground. NEC does not discuss any of this: what is essential to protect all household appliances.
Better is to answer the OP’s question by learning well proven concept that you never heard before. Better is to ask questions about how to make earthing exceed what code requires - rather than argue the irrelevant. Defined is how protection was done successfully well over 100 years ago. Better earthing for appliance protection is an ’art’ - that you apparently refuse to learn because the NEC does not discuss it.
NFPA is a human protection code; insufficient for transistor protection. Transistor protection both *meets* and *exceeds* those human safety requirements.
Human safety discusses resistance. Transistor safety also addresses impedance and equipotential. NFPA does not discuss the latter two. Because NFPA is only about human protection.
First you need to start with what is the intention of the National Electrical Code.
I did. Stated repeatedly in multiple posts. Appliances protection both *meets* and *exceeds* what is required by human protection codes such as NFPA.
IEEE defines how to exceed those codes. IEEE say why ’whole house’ protection is 99.5% to 99.9% effective. Plug-in protectors have no earth ground - maybe add another 0.2% protection. None of that contradicts what is good earthing for human protection and remains insufficient for appliance protection.
More quotes from various IEEE sources:
It is important to ensure that low-impedance grounding and bonding connections exist among the telephone and data equipment, the ac power system’s electrical safety-grounding system, and the building grounding electrode system. ..Failure to observe any part of this grounding requirement may result in hazardous potential being developed between the telephone (data) equipment and other grounded items that personnel may be near or might simultaneously contact.
Low impedance - not low resistance.
Martzloff’s 1994 IEEE paper says same about impedance because a protector (SPD) is only as effective as its earth ground:
An effective, low-impedance ground path is critical for the successful operation of an SPD. ... Therefore, an evaluation of the service entrance grounding system at the time of the SPD installation is very important.
An IEEE guide shows a protector, connected to a wall receptacle safety ground, earthing an 8000 volt surge destructively through a nearby TV. That protector was not connected low impedance to earth ground; was too close to and therefore damaged a nearby appliance. Again, protection defined by impedance - a short connection to earth. Protection not provided by a wall receptacle safety ground - that has low resistance and high impedance.
That same guide defines earthing that must exceed NFPA requirements:
To achieve optimum overvoltage protection, the connecting leads between the SPDs and the panel or protected equipment should be as short as possible and without sharp 90-degree bends.
90 degree bends and long wires (ie more than 10 feet) increase impedance (but not resistance). Therefore reduce appliance protection. NEC defines human protection; not appliance protection. Unfortunately electricians, who are taught code, are not taught concepts such as counterpoise, equipotential, and impedance. Concept necessary to upgrade earthing for surge protection.
Low impedance connection to single point earth ground is why the Cutler-Hammer and Leviton ’whole house’ protectors are so effective. With numbers (ie 50,000 amps) that define protection from direct lightning strikes. Because a protector is only as effective as its earth ground - including a low impedance connection.
Also critical is inspecting the ’primary’ surge protection layer - that is ignored by NFPA and NEC.
I have yet to hear of a residential electrical contractor that checks for earth resistance.
No standard was defined to measure that resistance. A 25 ohm number is too subjective Rather than play games with local inspectors, electricians routinely earth two ground electrodes. Then nobody can argue about 10 ohms measured one way and 40 ohms measured some other hardware or method.
First my comment is part of the total response I gave to the question gdnrbob asked in a post.
Quote
gdnrbob said: So, it seems the ground may be a place I should be inspecting more closely. As my house is almost 100 years old, is there any way to test a ground? Or, is there any way to add a newer/more effective ground? Thanks Bob
Does gdnrbob’s 100 year old house have a Concrete Encased Electrode (Ufer ground)? No.....
So what does gdnrbob possibly have for a Grounding Electrode System? First it would help to know when, the year, the electrical service was last updated. IF the house has a steel or copper domestic water line that is, at least 10ft in length, buried horizontally in the earth, that is a grounding electrode as per NEC. IF that is the case there is a very high probability it is supplemented by at least one 8ft ground rod. IF the water line is plastic then more than likely he has two 8ft ground rods, minimum, making up his grounding electrode system for the electrical service. The above would satisfy older NEC bare minimum requirements. As always the AHJ has the final say.
westom said: No standard was defined to measure that resistance.
Are you saying there is not a recognized, accepted, electrical industry standard for testing soil resistivity? I thought ANSI/IEEE recognized the testing equipment when used as directed by the manufacture, of the test equipment. Yes, the equipment test, to be credible, must be preformed by a qualified person trained on its’ use.
weston said: Rather than play games with local inspectors, electricians routinely earth two ground electrodes.
Games? Which is cheaper for the Residential Electrical Contractor? Pay a certified Power Quality company to test the electrode soil resistance and produce a certified test report for the electrical inspector, and possibly the Utility Power Company’s inspector, or just drive an additional 5/8" X 8ft ground rod?
//
In the 1968 NEC edition the "Concrete Encased Electrode" (Ufer ground) was first written into the code. AHJs (Authority Having Jurisdiction) could have made it mandatory if they wanted to. Maybe some did.
In NEC 2005 the language, wording, was changed making it mandatory for new construction. Of course that doesn’t mean all States and or local AHJs adopted the 2005 NEC change. My State did but not my city’s AHJ. Just going from memory I think the AHJ adopted the mandatory change around the year of 2009. Probably was when the AHJ adopted the NEC 2008 code in January of 2009,(In part with deletions and amendments). I don’t remember for sure..... I do know in 2007 it was not mandatory in my city. .
westom said: Soil conductivity (resistance) is relevant for code requirements - that only address human safety. Grounding for appliance safety is why Ufer grounding (to exceed code requirements) is popular.
First you need to start with what is the intention of the National Electrical Code.
2014 NEC Article 90 Introduction
90.1 Purpose.
(A) Practical Safeguarding. The purpose of the National Electrical Code is the practical safeguarding of persons and property from hazards arising from the use of electricity.
"and property".
Then you need to move onto 250.4 (A)(1)
Electrical System Grounding. Electrical systems that are grounded shall be connected to earth in a manner that will limit the voltage imposed by, lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation.
IEEE
The IEEE Green Book also states that ‘field experience and theoretical studies have shown that arcing, restriking, or vibrating ground faults on ungrounded systems can, under certain conditions, produce surge voltages as high as six times normal. Neutral grounding is effective in reducing transient voltage buildup from such intermittent ground faults by reducing neutral displacement from ground potential and reducing destructive effectiveness of any high-frequency voltage oscillations following each arc initiation or restrike,’
Earth grounding for the protection of electronic equipment, Micro processors, Data Processing Centers, Others? What about the electrical equipment and appliances found in the home? What doesn’t have a Micro Processor in it today, or at least electronics?
Again, the IEEE Green/Emerald book recommends a ground resistance of 5 ohms or less.
I have yet to hear of a residential electrical contractor that checks for earth resistance.
No standard was defined to measure that resistance. A 25 ohm number is too subjective Rather than play games with local inspectors, electricians routinely earth two ground electrodes. Then nobody can argue about 10 ohms measured one way and 40 ohms measured some other hardware or method.
Soil conductivity (resistance) is relevant for code requirements - that only address human safety. Grounding for appliance safety is why Ufer grounding (to exceed code requirements) is popular. Earthing for protection is an art.
Earth ground for protection involves conductivity and equipotential. For example, a ’whole house’ solution was properly earthed. They still suffered damage. A vein of graphite existed behind the house. Best path to earthborne charges was incoming on AC mains, ignored a service entrance earth ground, passed through household appliances, then out the back of that house into that conductive graphite vein.
Solution surrounded that house with a 2 AWG bare copper ground wire. Then single point earth ground was entirely beneath that house. Best equipotential eliminated future damage. Then a best connection to distant earthborne charges was outside around the house; not through it.
Other considerations. Earth electrode must be over 8 feet deep. If any are loose, then some event (maybe lightning) created that looseness if not enough electrodes were earthed. Always learn from mistakes. Damage happens because a human made a mistake.
In one FL case, lightning kept striking an outside wall. So they installed lightning rods. Lightning still struck that wall. Lightning (like other destructive surges) found a best path to earth via plumbing that connected to deeper limestone. Lightning rods were only earthed in sand. Solution was a longer electrode to make contact with that deeper and more conductive limestone. Then lightning stopped striking a bathroom wall.
Protectors are simple science. A ’whole house’ protector must be at least 50,000 amps to survive even direct lightning strikes (ie 20,000 amps). Earth ground (not a protector) does the protection.
Inspect a ground hardwire from the breaker box. If it goes up over the foundation and down to an earthing electrode, then it meets code. (It has low resistance and high impedance.) Surge protection compromised. That hardwire has excessive impedance (ie greater than 10 feet long), has sharp bends, and is not separated from non-grounding wires. Effective protection exists when that hardwire goes through a foundation and down to earth. Then it is shorter. No sharp bends means significantly lower impedance (not resistance). Is routed with more separation from other wires. Then a ’whole house’ protector has better earthing. A protector is only as effective as its earth ground.
Above is a ’secondary’ protection layer. Each layer is only defined by its earth ground - not by any protector. Also inspect your ’primary’ surge protection layer. Pictures (and not text) about half way down after the expression "more safety hazards" demonstrate what to inspect: http://www.fpl-fraud.com/
Some examples demonstrate this ’art’ of protection. Equipotential and impedance apply. Protection is always about where hundreds of thousand of joules dissipate. A protector is only as effective as its earth ground.
gdnrbob said: So, it seems the ground may be a place I should be inspecting more closely. As my house is almost 100 years old, is there any way to test a ground? Or, is there any way to add a newer/more effective ground? Thanks Bob
When was the last time the electrical service was upgraded? Approximate year?
Yes the ground, Grounding Electrode to soil resistivity can be tested. Some commercial/industrial electrical contractors have the proper equipment to preform such a test. It is not uncommon though for an electrical contractor to hire a company that deals in Power Quality to preform the test. The Power Quality Company will preform the test and then supply the Electrical Contractor the test data results.
IEEE, just going from memory, recommends 5 ohms or less. 2 ohms or less is preferred.... If the Grounding Electrode to soil resistivity is greater than 5 ohms the Power Quality Company will make recommendations to the electrical contractor how to get a 5 ohm or less soil to grounding electrode resistance reading. It’s usually accomplished just by driving a new ground rod deeper into the earth.
Where you live in the US has a lot to do with soil resistivity. Just the changing of the 4 seasons can have an impact on the electrical service grounding electrode to earth soil resistance. What part of the country do live in? http://droughtmonitor.unl.edu/
I would first hire an electrical contractor/electrician to check what you have now to see if it meets the bare minimum NEC code as well as the local governing body (AHJ) for the minimum required electrical service grounding system, (Grounding Electrode System) for an electrical service in your area. In some areas the standards may be set by the Utility Power Company in conjunction with the AHJ, (Authority Having Jurisdiction).
Worth noting, NEC says if the grounding electrode to earth resistance is greater than 25 ohms an additional earth driven ground rod shall be installed. That’s it, NEC is satisfied. No further testing is required... I have yet to hear of a residential electrical contractor that checks for earth resistance. To meet NEC code all they have to do is drive a supplemental ground rod.
Every incoming wire must first share that single point earth ground. A hardwire connection that is direct (ie TV cable, satellite dish) or that is made via a protector (telephone, AC electric).
I have dual solid copper large ground rods pounded in over 8' apart and large copper solid core ground wire running the them (in series) to my house feed/meter head. From there, I have an EP 2050 waveform regenerator+surge suppression on my main house panel and EP-2750 ground filters on the dedicated circuit in the subpanel and the feed from main house panel. Upstream are my power conditioners in the room. The EP units with proper deep earth ground is a very effective combination. See my system page for more details.
That Ufer ground looks very interesting. Thanks for bringing it up. I am always amazed by what information can be gotten on the internet. Whart, don't worry about hijacking my thread. I enjoy learning new things.
So, it seems the ground may be a place I should be inspecting more closely. As my house is almost 100 years old, is there any way to test a ground? Or, is there any way to add a newer/more effective ground? Thanks Bob
@westom I hear you Westom. I've got layers of stuff to wade through. Much depends on whether I build from scratch or work with an existing structure. When I have more info on what I'm dealing with, I'll be posting here-perhaps a new thread, since I don't want to highjack this one (any more than I have). Thank you. Good holiday to all.
If isolation transformers did that protection, then a utility transformer that provides AC power means no anomalies exist. Other potentially destructive anomalies act just like lightning. We simply use lightning as an example of all other potentially destructive anomalies created by stray cars, grid switching, tree rodents, linemen errors, and wind.
Even existing buildings must have earth ground inspected - often upgraded. Any earth ground that only meets today's human safety codes (ie NEC) is often insufficient earthing for appliance safety. Plenty of questions about earthing should exist. Even underground service does not protect from surges - including direct lightning strikes.
For example, a separate structure may require its own 'whole house' solution. Generally a separation of more than 25 feet is a ball park number for a building that is not protected by 'whole house' protection in a main building.
Back to that isolation transformer - one that is already doing your 'primary' protection. Same earthing requirements that make your 'secondary' protection layer effective also must be inspected in that 'primary' protection layer. More reasons why so many previous paragraphs should have resulted in plenty of questions. Even a transformer in an Equi-Tech cabinet is only as effective as its earth ground.
Westom--thank you. I know I looked at some of this when I did my current room, but it wasn't constructed from the ground up. This one may or may not be~ a separate building, hopefully with separate service from the house. (Many of the places in Austin have "guest houses" on the property- I'd use that for my music and office). I also have a large Equi=Tech wall cabinet with big isolation transformer that I will probably work into the equation--not for protection against lightening, but to isolate the system from anomalies on the line. (It is a balanced power set up, which raises a host of other issues). I've got some leg work to do.
More effective protectors use L-N, L-G, and G-N protection. Furman only uses L-N. Does not matter. They are selling to people who have no idea if protection works. Furman’s near zero protection is hyped subjectively as 100% protection. Because eyes routinely glaze over with numbers. And fewer do not know what those numbers mean.
Second, if all 6500 amps go line to neutral, then at 188 volts, it can ’block’ or ’absorb’ a surge that is less than 32 joules. How does that ’block’ or ’absorb’ surges that are near zero - hundreds or a thousand joules? It doesn’t. They needed you to completely ignore or completely misunderstand numbers. Your numbers define protection as close to zero as possible without being zero protection. Just enough above zero to by hyped as 100% protection.
Third, if 6500 amps are incoming, then what is an outgoing path? It is electricity. Both an incoming and an outgoing path to earth must exist. Incoming on AC mains. At the exact same time, that current is outgoing via attached appliances. They market to consumers who forget how electricity works and how surges do damage. Incoming on AC mains. At the same time, outgoing destructively to earth.
Fourth, that L-N protection for a surge seeking earth ground means a surge incoming on a black (hot) wire now has two destructive paths into attached appliances. No problem for tiny 100 joule surges. Since surges that tiny are routinely converted by electronics into rock stable, low DC voltages to safely power semiconductors. Better protection is already inside electronics.
Thank you for providing numbers. Numbers demonstrate what does work, what are expensive scams, and what you did not understand. Furman protector does nothing for surges inside and hunting for earth ground destructively via appliances. Protection has always been about earthing a destructive transient BEFORE it can enter a building. Always - as was standard even over 100 years ago.
whart - best time to install surge protection is when footings are poured. A protector is only as effective as its earth ground. Learn about Ufer grounds. Ufer originally pioneered this technology to protect munitions dumps from direct lightning strikes. Same protection is in telephone COs so that a $multi-million switching computer does not suffer damage during thunderstorms. COs typically suffer about 100 surges per storm. How often is your town without phone service for four days while they replace that computer? Why is service maintained during and after each storm? Learn about the most critical item in a surge protection *system* - earth ground. Telcos do not waste money on Furman type protection.
One example of how a radio station installed an Ufer ground and what is best protection for so little money: http://scott-inc.com/html/ufer.htm
Effective manufacturers who provide protectors from direct lighting strikes will not warranty protection. Best warranties are found on the least effective (and high profit) devices. Type is irrelevant. Type defines human safety parameters. For appliance protection, that protector must conduct at least 50,000 amps. Protection is never defined by a protector. Protection is defined by quality of and a low impedance (ie less than 10 foot) connection to single point earth ground. Ufer ground is an ideal example. Nobody will warranty what does the protection - earth ground.
That protector demonstrated by jea48 is rented from and installed by electric companies. Often a girl who reads meters might install it. Effective protection is that easy - but only if your earth ground both meets and exceeds code requirements.
This issue is timely for me since it looks like I’m finally moving from NY to Austin. I will be hiring an electrical contractor there for a build out. (I guess I need to buy the building first but planning is part of the process of selecting the right property/zoning/service for what I want to accomplish). @jea48 - you’ve always been a terrifically knowledgeable resource on matters electrical. I’ve sent you a PM. Could you take a look when you have a minute? regards to every one here- good holiday if you celebrate--looking forward to carrying on soon from Texas! bill hart
It may help to understand that a SMP acts like a low pass filter. It is always in the circuit, and has a -3 dB point of around 3 kHz. That’s really really good since most EMI/RFI filters start working at around 100 kHz.
The low-pass filter is always there, and causes any very fast surges to present themselves as voltages across the protection device but NOT your appliance regardless of the speed of the surge itself. At the appliance, just like in a speaker, this will slow down the rise time of the surge, giving the rest of the device time to clamp on and further limit the voltage.
I believe, and it's been a while, that the 1 nanosecond time, refers to the time for the SMP to add a pole. That is, it goes from a 1-st order to 2-nd order filter, or something like that. Thanks to the low-pass effect, it has plenty of time to do this before issues arise.
The surge protection is always on, however it has a clamping mode. It's deceptive (or overtly conservative) because the surge protection slows the surge down by a huge amount. The clamp time and clamping voltage (188V) are severely below a damaging surge's potential.
This is different than a parallel circuit where it does NOTHING for several milliseconds (or whatever) and then becomes a short to ground.By that time your gear has already felt possibly several thousand volts.
I guess in my mind if over 6500 amps gets past my Square D 20 amp breaker to my equipment in under 1 nanosecond then I just have to give up and call the insurance company. There are no absolutes. If the surge is due to a nuclear strike then you have much bigger problems than your audio equipment. Just sayin'!
If warranty proved anything, then GM products have always been superior to Honda and Toyota. Good luck getting every GM warranty honored. Dealers,. too often, get stuck with costs. So dealers will do anything to avoid honoring that warranty.
A lesson from free market economics - in numerous industries. A best warranty often indicates an inferior product. Salesmen will do anything to make a sale.
Protection for over 100 years has always been about where hundreds of thousands of joules harmlessly dissipate. Only one item has always existed in every protection 'system': earth ground. A protector is only as effective as its earth ground. A plug-in protector does not have and will not discuss that low impedance connection to earth.
Best protection (that is also a least expensive solution) is properly earthed 'whole house' protector. Then a homeowner inspects THE most critical item in that solution. Every incoming wire (TV cable, satellite dish, telephone, OTA antenna - every) must connect low impedance to single point earth ground.
That is only 'secondary' protection. An informed homeowner also inspects their 'primary' surge protection layer.
All this described previously with spec numbers. Numbers separate an informed recommendation from those who recite advertising, hearsay, and wild speculation. Who even mistakenly believe a warranty rather than specification numbers.
Protection is always about where hundreds of thousands of joules harmlessly dissipate. Then protection even from direct lightning strikes remains functional for decades. Because protection is only as effective as its only required and so essential component - earth ground. Not wall receptacle safety ground. Earth ground.
What is a "Power Surge"? "Power surges" means an electrical transient or spike on the AC power or communication lines, including those caused by indirect lightning, against which surge protective devices of this type are generally designed to protect as recognized by industry standards.
That is not proof that the SPD will protect the electronics
used in equipment or appliances found inside the house from a direct
lightning hit to the electrical service of the house
Quite so, it is not proof. Again, you seek an absolute, iron-clad, no-fault guarantee, and you’re not going to find that in this realm.
On anything. That's why I wear a seatbelt, even though it doesn't offer the kind of guarantee you seem to demand.
Type 1 Surge Protective Devices are typically mounted on the line side
of the main service entrance (between the utility pole and where your
electricity enters your service panel). They protect against external
surges caused by lightning or utility capacitor bank switching.
That is not proof that the SPD will protect the electronics used in equipment or appliances found inside the house from a direct lightning hit to the electrical service of the house, or, if it hits some other part of the house first.
A direct lightning strike/stroke to the electrical service of a house IS NOT considered an "electrical surge" is it? What is the average voltage and current a direct lightning strike/stoke could deliver to the electrical meter socket/meter/SPD mounted on the outside of a house?
Equipment fuses are not designed to protect you from electrocution, but the safety ground (that nuisance that audiophiles love to remove) and Ground Fault Current Interrupters are (like the outlets in your kitchen, I hope).
GFCI trip at around 5 mA. That’s MILLI-amperes, while a circuit breaker is around 15 A, and typical audio gear in the range of 1-10 Amps (typical, not exhaustive.
Let’s say a tube preamp has a 1 Amp fuse, that’s 20 x more current than would trip a GFCI. The figure I read most often is that it is estimated that that about 10 mA of current is lethal under ideally fatal conditions.
Preventing damage from lightning is a difficult thing, in no small part due to the speed caused by the sudden arcing. Parallel systems require time to activate, series do not. Parallel systems rely on the drain location being low impedance, series do not.
An EMI pulse from a lightning (or nuclear) strike can induce current in the cables in the walls themselves, it does not necessarily telegraph in from the transformers. Series devices present a very high, always on, impedance to these rapid pulses, so the majority of the voltage will be presented at the blocking coil, instead of your precious gear.
There are also other sources of induced surges. Cable TV, phone and network wiring. Then there is stupid stuff like wind gusts on an antenna. I’ve suffered several losses of Satellite TV receivers not from lightning but from wind, I assume caused by static electricity developing across the broad antenna surface... and zap! Solved eventually by using a professional, bullkhead mounted surge arrester! :)
Impedance is taught to engineers; but not to electricians. Electricians are taught code - for human safety. Transistor (appliance) safety means doing things that both meet and exceed code. Connection to (ie impedance) and quality of single point earth ground define protection even from direct lightning strikes. As we engineers did decades ago.
Really? Where did you hear that about electricians? And I don’t mean residential wireman. Not meant to demean a residential wireman but they do not have the training or the on job experience that a journeyman (Class A Licensed) electrician has that works in the commercial and or industrial electrical industry.
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westom said:
Fuses do what they are designed to do. Something completely different and invented by wild speculation is a "fuse myth". Fuses protect human life AFTER hardware damage occurs. So that fire and electrocution does not happen. Only myths and wild speculation claim a fuse will protect hardware. That myth is invented by many who ignore manufacturer specification numbers.
A fuse does not directly protect human life. That is not its’ intended purpose. As for NEC its’ purpose is to provide overcurrent protection, short circuit protection, as well as ground fault circuit protection for branch circuit wiring, feeders, ungrounded hot busing of panelboards, switch gear, as well as disconnect switches. There are others...They also are used in protecting power transformers from being overloaded while providing short circuit protection as well as short circuit ground fault protection. They also provide short circuit protection for larger than small fractional HP motors. See NEC Article 430 as well as Article 440.
A fuse will not protect a person from electrical shock or electrocution. I have known of electricians that were electrocuted and the power was still live when they found them dead. Some were still connected to the live power. Fuses could care less what the connected load is as long as it does not exceed it’s ampere rating for a duration that will melt the internal fuse link breaking the circuit.
Fuses found in electronic equipment, if sized properly, can protect the equipment from severe damage. First hand example. A few years ago a 6550 power tube shorted in my ARC power amp. The shorted tube caused an overload in the HV, high voltage, DC power supply which caused the HV secondary winding of the power transformer to overload which caused the primary winding of the transformer to overload which exceeded the ampere rating of the AC line fuse, protecting the primary and secondary winding of the transformer, causing the fuse to blow open. Imagine what could have happened if the fuse was bypassed.... No other damage was caused to anything else inside the amp. The line fuse did what it was designed to do. It did indeed protect the equipment. .
The only thing that would totally protect a home from a direct lightning strike would be to totally enclose it inside of an earth grounded Faraday Cage. Though that could prove to be quite expensive ... If there is real world testing documentation, conducted by a recognized 3rd party testing laboratory, that proves a whole house SPD in conjunction with an average to good low resistance earth soil to grounding electrode of, say, 5 ohms or less, then please produce the documentation/white paper.
I’m not sure what your point is. No safety device provides 100 percent protection against all threats under every circumstance every time. Life doesn’t work that way, but that doesn’t stop people from using seatbelts, does it?
Regardless, your statement below is false:
You won’t find any SPD that will protect your home from a direct lightning strike.
As I explained to you, Type 1 devices such as this are quite effective. But if you want an absolute, iron-clad, no-fault guarantee, you’re not going to find that in this realm.
The only thing that would totally protect a home from a direct lightning strike would be to totally enclose it inside of an earth grounded Faraday Cage. Though that could prove to be quite expensive.....
Or maybe hang a really big sign on the outside of the house where the electrical service and earth connection earth grounding electrode is located. Wordage something like, "Lightning Strike Here Only" with a big arrow pointing at the electrical service. Even then I doubt the best grounding electrode to earth soil resistance of 1 ohm could save all the electronics inside the house.
Of course there is no guarantee lightning is intelligent and can read the sign or would even care what the sign says. What if the lightning decided to hit that power roof vent unit on the roof instead of the electrical service?
Or maybe just the branch circuit wiring that is running all over the place in the attic space on top of the ceiling joists?
If there is real world testing documentation, conducted by a recognized 3rd party testing laboratory, that proves a whole house SPD in conjunction with an average to good low resistance earth soil to grounding electrode of, say, 5 ohms or less, then please produce the documentation/white paper.
I didn't carefully go through every single comment, but I'm pretty sure there's one thing you guys missed. And its understandable because all these companies want you to miss it. With regards to lightning protection, there are plenty of companies that directly or indirectly lead you to believe they're products protect against a lightning strike. I'm not sure about some of the industrial units that others have mentioned, but the ones for AV use, really can't protect against a lightning strike. This is a gray area, because these companies really do protect against lightning. They do it in the for of insurance. Each company has its own procedure, but you send them some info on your system and ho policy, and you have lightning coverage (hopefully).
I only know this because I used to be a Panamax dealer years ago. They would rather offer you lightning protection even if their products can't do it, because that's what customers expect. Everyone's afraid of lightning. They feel they would lose far more business by not covering for lightning damage than if they just paid for peoples systems in the event of a strike.
Personally, I don't have an issue with them doing it this way because it looks like there aren't any reasonably priced solutions. Better the insurance than nothing. But I think they should be very clear about the insurance. I know a lot of people will just leave they're systems plugged in all the time because they feel the surge protector is protecting them, not the insurance. Add to that, most customers have no idea they need to send in all the info in to be covered, so they end up with no coverage and don't know it.
Those that deny do not even read what is posted. Only read what they want to read. Nobody said a fuse is a myth. Defined is the "fuse myth". Quoted so that what was posted might be read this time:
For example, a fuse myth is promoted subjectively - without numbers.
Fuses do what they are designed to do. Something completely different and invented by wild speculation is a "fuse myth". Fuses protect human life AFTER hardware damage occurs. So that fire and electrocution does not happen. Only myths and wild speculation claim a fuse will protect hardware. That myth is invented by many who ignore manufacturer specification numbers.
That "fuse myth" was expose three times over with numbers. Only one (who reads what he wants to believe) would read, "fuses are a myth".
gndrbob - that Eaton is part of an effective protection 'system' from direct lightning strikes ONLY if it connects low impedance to what is doing protection. Again, the world’s best protector does not protect from any potentially destructive surge (ie lightning). A protector is only as effective as its earth ground. Single point earth ground - as required by code (despite denials) - does that protection. A protector is only as effective as its earth ground.
No earth ground means no lightning protection.
Lightning rod does not protect from lightning. Lightning rod is effective when it connects to what protects from lightning - earth ground. ’Whole house’ protector is effective when it connects to what protects from lightning - earth ground. One system protects a structure. Latter system protects appliances inside that structure even from direct lightning strikes.
Earth ground defined by code may be insufficient. That Cutler-Hammer (Eaton) and Siemens are effective protection from direct lightning only when earthing exceeds National Electrical Code (NEC) requirements.
For example, find a bare, quarter inch, solid copper wire that connects your breaker box to earth. A ’whole house’ protector is compromised if that wire goes up over a foundation and down to an earth ground rod. Wire is too long. It has sharp bends over a foundation. It is bundled with other non-grounding wires. All compromise protection.
Whereas that ground wire is sufficient for code (for human safety), it is insufficient for grounding a ’whole house’ protector (for transistor safety). That hardwire must be routed through a foundation and down to earthing electrodes to be shorter and to eliminate sharp bends.
Impedance is taught to engineers; but not to electricians. Electricians are taught code - for human safety. Transistor (appliance) safety means doing things that both meet and exceed code. Connection to (ie impedance) and quality of single point earth ground define protection even from direct lightning strikes. As we engineers did decades ago.
Protection from direct lightning strikes is provided by what makes Eaton and Siemens protectors effective. A low impedance (ie hardwire not inside metallic conduit) connection to single point earth ground.
Cable already has best protection. A hardwire, required by code and installed for free by a cable company, connects directly to a same ground. That is best protection.
Telephone cannot connect direct to earth. So your telco installs a ’whole house’ protector for free. That protector is only doing what an above hardwire does better. Connects to earth.
Only incoming utility that may have no protection is AC electric. Protection is required on other wires but not on AC electric. Protection even from direct lightning strikes exists only if that Cutler Hammer or Siemens protector connects low impedance to earth.
Term ’low impedance’ is deliberately repeated obnoxiously. Because low impedance connection to single point earth ground is critical for effective protection. A protector is only as effective as its earth ground.
That is ’secondary’ protection. Also ask about the ’primary’ protection layer.
You won't find any SPD that will protect your home from a direct lightning strike. If you find a manufacture that claims it will you best read the fine print.
Of course no device is absolutely 100 percent effective. However, Type 1 devices are designed to protect from direct lightning strikes and are quite effective. Note that not all electric utilities allow them.
One such device is Eaton CHSPT1, which is UL compliant.
the SPD should be installed as close as possible to the load side of the electrical service panel main breaker.
Oh no, not at all. A Type 1 device must first connect to the transformer secondary, not the load side. (Although I''m pretty sure you can put it on the load side as well.) Please check the application sheets for the Type 1 device of your choice.
All earth connections should connect to a single point to the electrical service entrance neutral conductor.
You won’t find any SPD that will protect your home from a direct lightning strike. If you find a manufacture that claims it will you best read the fine print.
Like westom said in his post the earth connection is the most important part for protecting your home from a nearby lightning strike.
As for the Siemens SPD I do not have any opinion one way or the other. https://www.youtube.com/watch?v=7Dj33YVppDk If it says it will protect from a direct lightning strike thought, it will not... It may not even protect your electronics in your home from a nearby lightning strike. The only 100% sure way to protect your audio and video equipment during a lightning storm is to unplug it from the wall receptacle. Same goes for any coax cable connection from a cable TV provider or a satellite dish. Same goes for an Ethernet cable connection from a router that is connected to the outside world by cable or a phone line.
Here is a great video to watch. I attended a power quality surge protection seminar a couple of years ago and seen the demonstration first hand. https://www.youtube.com/watch?v=5Wb79cXmSlc
The thing that I visually remember most is the SPD should be installed as close as possible to the load side of the electrical service panel main breaker. The first two breaker spots on ether side of the panel is where the 2 pole breaker for the SPD Line 1 & 2 to connect. (IF there are breakers in the two spots, needed for the SPD’s 2 pole breaker, have the electrician move them elsewhere in the panel. It will take him 5 to 10 minutes tops!) Mount the SPD as close as possible to the outside of the panel enclosure where the 2 pole breaker is installed. The wire leads from the SPD should be kept short.
IF The SPD is installed inside the electrical panel, hidden from view, how will you be able to see the indicating lights on the unit telling you the device is still good and working properly? SPDs that use MOVs do not last for ever. That’s why the good SPD devices have multiple MOVs for each surge function of the device. You should always check the SPD after any lightning storm in your area.
Any sub panel after the main electrical service main panel also needs an SPD installed. Again the SPD should be installed as close as possible to the feeder conductors, wires, feeding the sub panel. The first two breaker spots for the SPD’s 2 pole breaker installation.
MAKE SURE you have the electrician check the main grounding system (Grounding Electrode System) for your home’s electrical service. Clean, if needed, and tighten all connections. No such thing as over kill here. And as westom said, a single point earth connection is a must. All earth connections should connect to a single point to the electrical service entrance neutral conductor. .
One should learn these basic and well understood concepts BEFORE posting denials.
a fuse myth is promoted subjectively - without numbers
I’m not sure why you call fuses a "myth."
How does a millimeters gap in a fuse block what three miles of sky could not?
Don’t be silly. A fuse is not designed to do that.
One should learn these basic and well understood concepts BEFORE posting denials.
Agreed! Please take some time to learn that fuses are not a myth.
Subjective reasoning is how junk science gets promoted. One claims Furman does effective protection. But could not post even one Furman spec number that says so. Because Furman does not claim effective protection - except subjectively in sales brochures where lying is legal.
That’s absurd. The Furman units - and other similar devices - are in wide use and their effectiveness is demonstrable. It’s not clear why this troubles you so.
Facilities that cannot have damage properly earth all incoming wires. Some wires do not even have surge protectors. A hardwire connects low impedance (ie less than 10 feet) to single point earth ground.
Whoa ... careful there! You might want to read the NEC and your local codes. There’s really no such thing as a "single point earth ground" in an NEC-compliant installation. NEC requires all grounds to be bonded together at the service panel. And in many installations, code requires more than one ground rod. Clearly, you simply do not know what you are talking about.
Protectors are simply connecting devices to what does protection.
Silly semantics.
Ineffective and grossly overpriced ’magic boxes’ (ie Furman) have no earth ground. And will not discuss it.
And why an item that needs most attention is the single point earth ground.
Again ... " single point earth ground" is not code complaint and is potentially dangerous. You simply do not know what you are talking about. This is why EEs and electricians are licensed.
Thank jea, but that model specifically states that it doesn't protect from lightning strikes-which less common in my area but definitely a concern. And, I definitely will be using a licensed electrician to install.
A fuse provides "protection" and earth ground has nothing to do with its effectiveness. And your reference to " hundreds of thousands of joules" is an arbitrary figure.
Obvious is when one recites hearsay. For example, a fuse myth is promoted subjectively - without numbers. Those numbers: 1) Surges do damage in microseconds. Fuses take tens of milliseconds or longer to respond. Numbers make it obvious. A fuse does not do and does not claim to do such protection.
2) How does a millimeters gap in a fuse block what three miles of sky could not? It doesn’t. But again, the subjective and inaccurate speculation is exposed by numbers.
3) Fuses have a voltage number. For example 250 volt. If a surge voltage exceeds that number, then a blown fuse keeps conducting. One should learn these basic and well understood concepts BEFORE posting denials.
People who do this stuff use numbers such as hundreds of thousands of joules. If one knew otherwise, then an energy number is posted rather than make subjective denials. Subjective reasoning is how junk science gets promoted. One claims Furman does effective protection. But could not post even one Furman spec number that says so. Because Furman does not claim effective protection - except subjectively in sales brochures where lying is legal.
Facilities that cannot have damage properly earth all incoming wires. Some wires do not even have surge protectors. A hardwire connects low impedance (ie less than 10 feet) to single point earth ground.
Protectors are simply connecting devices to what does protection. Every protection layer is only defined by one ’energy absorbing’ item - its earth ground. Ineffective and grossly overpriced ’magic boxes’ (ie Furman) have no earth ground. And will not discuss it.
’Whole house’ protector is a ’secondary’ protection layer. Informed consumers should also inspect their ’primary’ protection layer. Over 100 years of science and experience are why ’whole house’ protection is routinely installed in every facility that cannot have damage. And why an item that needs most attention is the single point earth ground. Specification numbers say why including 50,000+ amps, microsecond transients, low impedance connection to a single point earth ground, and hundreds of thousands of joules. This superior solution also costs much less - about $1 per protected appliance. Even a Furman needs that protection. Made obvious when one attempts to post manufacturer specification numbers. None were posted because none exist.
That Eaton (Cutler Hammer) protector is an effective one. Other manufacturer are also known for integrity including Intermatic, Square D, Ditek, Siemens, Polyphaser (an industry benchmark), Syscom, Leviton, ABB, Delta, Erico, and General Electric. In every case, model numbers are irrelevant. Critical is its current rating (at least 50,000 amps) and that all so important hardwire for a low impedance (ie has no sharp bends) connection to single point earth ground. Electric companies also rent them. So easily installed that the girl who reads a meter may install it.
Many of them are panel brand specific, so I would consult with your electrician as to whichever is best for your needs. They all work on the same parallel principle, with MOV’s AFAIK. Not perfect, but they work much better at the panel than at the outlet.
Furman is very popular in professional use and a better value in the home than many "audiophile" power conditioners. The Series Mode surge suppression is built under license. Other users of the technology include SurgeX (unnecessarily expensive) and PS Audio.
Note Furman makes like 3 dozen models. Look for SMP, and LiFT to help you decide.
Given a choice, I am completely confident in the Furman’s and that’s what I use on my gear but would also install panel protectors to save things like my microwave, Tesla charging station, etc. :)
Furman's claim to fame is their application to commercial or professional sound applications. They maintain nearly all of the market in professional sound reinforcement systems. Using the "guilt by association" model, one could draw the conclusion that if professional sound companies by a vast majority utilize and rely on Furman products to protect their systems, they will probably work for your home system as well. I'm not saying that their products will protect your system from a direct lightning strike but they are obviously reliable if they are the standard in professional applications. Let me make it clear that I have no affiliation with Furman whatsoever.
Thanks everyone, it looks like this is more complicated than I thought. Eric- your Home Depot link list many different units, did you have one in particular that you would recommend? Jea48, thanks for the links, though they seem more geared to an industrial setting. It looks like the layered approach is the way to go. So, what do any of you recommend for the mains box?
I installed an EP 2050 after a surge took out a Vandersteen amp....never had a problem since installation.....it actually had a benefit to the sound of the system.
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