Checking Earth Ground--problem

What year was building constructed? What is soil? Nothing (reasonable) will test for proper connection to and quality of earthing for lightning protection. A utility typically will not even verify earthing. First, earthing is onwer's problem and your electrical inspector's concern. Second, a utility will only inspect for human safety problems.

Even with plastic pipes, your building must still be earthed. That means a bare copper wire out of breaker box AND means that wire is obvious where it goes into earth. That wire located to inspect it. Just one earth ground rod connected short to breaker box is a massive earthing improvement. Posted previously were inspections to make earthing even better. But again, there is no better solution than you personally doing that inspection, or hiring an electrician to identify the wires.

No reasonable testing exists for how that wire is routed. None. Expensive testing equipment will typically only report earth conductivity. But you have a ballpark grasp of conducitivity by defining soil - a question asked above. Again, visual inspection as defined earlier. No way around that requirement.

Does your AC electric conform to post 1990 code? Otherwise, hire the electrician to upgrade earthing to post 1990 requirements and to install a 'whole house' protector. Again, and this should be obvious from previous posts - visual inspection. Defined was what you must look for. No reasonable replacement for visual inspection exists. There is no replacement for an earthing connection from each and every incoming utility wire (and that also included satellite TV dish) to that earth ground. But another part of the visual inspection that you must perform. Testing will not replace a visual inspection.

A properly sized protector cannot "accurately monitor their condition and indicate when they need to be replaced". A protector worse than undersized - grossly undersized - will vaporize. A light would indicate a failure that should not exist - if protector was properly sized. Protectors degrade. Minimally sized protectors (as defined by numbers previously) should be more than sufficient for 10 years. In MN (except in neighborhoods that have frequent lightning damage), that protector may be sufficient for your entire lifetime because it is properly sized.

If earthing is not sufficient to make a 'whole house' protector effective, then major code violations may exist. Just upgrading earthing to post 1990 requirements means a 'whole house' protector does something useful. Currently you are suffering damage because essentially nothing useful exists. You have virtually no protection. Either no protectors or plug-in protectors located too far from earth and too close to appliances.. Or your utilities do not share a single point earthing electrode.

Earth> ...

2000

I looked at the breaker box and the meter box. The meter box has two plasyic PVC pipes going into the ground and nothing else coming out of it. The breaker box has one plastic pipe going into the garage floor (it is an attached garage) and nothiong else going down. The ONLY copper I see coming out of either box is two things that look like small copper pipes (not cables) about 1/6th of an inch wide coming out of the breaker box, but they go up through the ceiling! The garage is on ground level and there's no basement.

I live in a townhouse/row house which is only open on one side, the other three sides have adjascent (attached) units. There are ten units in the structure. Is it possible the structure itself is grounded but not each individual unit?

Oddly, my computer was undamaged even though it was on and not plugged into a surge supressor. I guess I lucked out on that one. I got a surge strip for it a few days ago.

That wire located to inspect it.

Be aware that there is a difference between lightning arrestors and surge protectors. Generally (but not always) lightning arrestors are provided on the utility side of the meter by the utilty. Whole house surge protectors are installed after the meter demarcation point. A direct lightning stoke is just as likely to blow apart your surge protector as other parts of your wiring system. The currents can be incredibly high. That's what lightning arrestors were invented for.

Lightning causes surges, but surges can be caused by many additonal factors including routine utiltiy operations, overloaded lines, and equipment that starts and stops frequently. For example, if you are running a business office, you would not want your elevator circuits directly connected to your server room.

The best whole-house surge protectors do work and generally have "OK" and "Needs Service" illuminated indicators. Some have audible alarms.

Leviton is a good model. Here is one from Smarthome: (no affiliation)

Note that these are not cheap. Outdoor models are also available.

Proper surge protection in the North American system requires 3 mode protection. That is, the HOT to NEUTRAL, HOT TO GROUND, and NEUTRAL TO GROUND. The HOT to NEUTRAL protection mode does not require a ground.

Check with Underwriters Labs if you want to understand the difference between a cheap outlet surge protection and a large capacity whole house system. Surge protectors are rated in joules and generally the higher, the better.

Beachcomber

Any surge protector that does not earth a direct lightning strike and does not remain functional was a waste of money. Many other transients listed are made irrelevant by protection already inside appliances. How do we know? Everyone is not trooping daily to hardware stores to replace appliances damaged by switching transients. "Equipment that starts and stops frequently" would be destroying appliances everywhere every day if appliances already did not contain effective internal protection.

Effective 'whole house' protector is about earthing a transient - lightning - so that protection already inside appliances is not overwhelmed.

We install protectors for lightning - the typically most destructive transient. Protector must earth a direct lightning strike AND remain functional. Many of those plug-in type protectors with G-N, N-H, and H-N connections are so grossly undersized as to be vaporized by a potentially destructive transient. Some examples of ineffective protectors:

Necessary is a protector that earths lightning and remains functional. Minimally acceptable 'whole house' protectors for this task are 1000 joules and 50,000 amps. What is a typical direct lightning strike? 20,000 amps. Does all that current pass into the home? Not if the utility primary protector is also properly earthed. IOW 'whole house' protector - secondary protection - must be sufficient to handle a direct lightning strike. Utility's primary protector also makes that direct strike even less potentially destructive.

Just another reason why the primary protection system should be inspected:

A protector is installed for a most typically destructive event - direct lightning strike. Protector must earth that strike and remain functional. Other potentially destructive transients such as utility switching transients are made irrelevant by that protector installed for lightning protection.

I am wondering how direct. If a large bolt striked the lines right where they enter the breaker box, that would obviously be very different than striking the transformer down the block. Now, I barely understand the basics (E=I/R) so if my line of questioning is off, please understand. But it seems to me that a $200-300 whole house surge protector trying to shunt between 25,000 and 45,000 amps (direct strike) to ground is sort of like a traffic cop trying to keep a tsunami wave constricted to the main street, blocking it from going down a side street. The cop can blow his whistle until his face is red, the wave will just knock him down and go where it wants. Plus, the core temperature of a lightning channel is approximately

50,000 degrees Fahrenheit, isn't that enough to vaporize metal inside the surge supressor and turn it into plasma for a few microcesonds? I remember when it struck my dad's home CB antenna, it melted the copper coil and sprayed it out into the air, where it solidified as very small roughly spherical copper balls, similar to BBs.

Adam:

You are correct.

As a former broadcast transmission engineer, believe me... I experienced my share of lighting strikes at a transmitter facility. If it were possible to just buy once piece of equipment such as an oversize surge protector to solve all our lighting problems, then that's what we would do. This has not been the case.

Unfortunately, defending against lightning is a complex and sometimes expensive task. It requires a combination of good grounding, shielding, bonding, and surge protection.

Start with good grounding. Current techniques in high-resistance ground locations are starting to specify ground rods of 50 - 60 feet long (at least in commercial and industrial installations). Most studies indicate that such a ground will give a good, low resistance value of under 5 ohms or so.

Also Google UFER ground for a good alternative to ground rods.

Any conductive path to your house, electric wires (buried or not), cable tv, telephone lines, metallic piping, etc. is a potential pathway for bringing lightning inside the house. Commercial installations in high lightning areas will channel all of these through one-location, more or less, and often through a flange connected to a grounded copper bonding plate.

Your last defence is often the whole-house or whole-facility surge protector, which, if sized properly, will protect against all but the worst lightning strikes.

By the way, switching transients and other non-lightning related surges do cause damage to unprotected systems. It might take years before a failure mode manifests itself because it is a cumulative process. Most circuits are clean and free from such unpleasentries, but if you live downline from the local sawmill, you might have some trouble with your computers and laser printers.

Beachcomber

Read numbers yourself rather than posting speculations. Why would a responsible manufacturer spec 50,000 amps if it could not shunt 50,000 amps? Why are you making speculations while ignoring other parameters such as time and voltage? Direct strikes routinely hit telephone poles often without damage. Look at that earthing connection. If all earthing must be rods 60 feet deep, then everything struck is destroyed

- a 'woe is me' mentality for failure.

Put too much impedance in a path to earth, such as via a CB coil, then energy content increases massively. So of course a CB coil melted. It tried to stop the entire lightning bolt. Just another example of why protectors that try to stop surges fail. Why are plug-in protectors so ineffective? That CB coil demonstrates that protection by stopping or blocking lightning - high impedance - means failure.

Put lightning into perspective. As the US Forestry Service demonstrated, more than 95% of trees suffer a direct strike without appreciable damage. Many who see a rare, destructive strike falsely assume that all lightning strikes are that destructive. Earthing a direct strike with no appreciable damage is easy. Swallow those wild speculations. Take what was posted here - provided with professional citations - and confirm it yourself. You have numbers from responsible manufacturers. 50,000 amps. Which one is false? Them or your speculations?

Lightn> Most of the energy available to the lightning is converted along

A direct strike to a transformer was a direct strike to household appliances if incoming wires were not earthed (ie through a 'whole house' protector). So why did damaged electronics not explode inside the house? Based upon what you have posted, wires should have been blown from inside walls. Earthing a direct strike without damage is easy as even demonstrated by studies from the US Forestry Service. Are those numbers from GE, et al lies? That is what you have posted with speculation about a traffic cop directing a tsunami. You have numbers and solutions. At this point, you should be posting what that electrician found. You should already know if earthing meets post 1990 NEC requirements. Time for speculation is over. Posts should now contain facts of what actually exists?

BTW, why does a commercial broadcaster earth 60 feet deep? > I am wondering how direct. If a large bolt striked the lines right where

surge and monitoring generally means $$$$$$$$$$$

Manual checks are a waste of time. It is the grounding conductor/electrode that your interested in.

I am unaware any municipality that requires testing of the grounding, except in remodel or service change situations. I know and have written some specs for "performance grounding" no one would use it for a house.

Buy the plug in service panel unit, and as many ones in the house that you need. Then after every lightning season replace them. Way cheaper than testing, and the confusion that that will bring.

I would, but I don't know what numbers to read. I thought I had made it clear that my level of understanding on this subject was virtually nil, but apparently not.

Learning reality is exactly what I am trying to do, and I am learning a few things in spite of your posts. I would love to go to Lowes or Home Depot and learn more, but I am not ready to because I don't understand the forces involved well enough yet to ask intelligent questions about it. In case it isn't obvious, I don't even really understand how a surge protector works. That's why I came here first.

A number of times, you went out of your way to point out the fact that I was making wild speculations and to sarcastically and snidely point out how wrong I was.

I was just trying to frame a question, Did you miss my statement: "Now, I barely understand the basics (E=I/R) so if my line of questioning is off, please understand."

Do you follow? Can you comprehend what it means when someone says " I barely understand the basics... so if my line of questioning is off, please understand"?

Apparently not. But thanks anyway for ramming it down my throat repeatedly that I am an idiot. It really helps me understand electrical principles much more clearly.

Thank you, I appreciate the info on real-world experiences. Valuable information for me.

Thanks to you and others, I feel I know enough to put in my own earth ground setup. Unfortunately, I can't do this right now because I live in a townhouse, but it will be useful information especially if I ever move to a regular house. I guess I would need to hire an electrician to install a good ground rod in order to get the association's approval. Besides, the "yards" (tiny patches of grass) here are so small and crammed with electric, gas, cable and other utility lines and pipes, it's probably illegal for me to dig anywhere.

Interesting concept!! Grounding with rebar in concrete as part of the earth ground.

It sounds like the only setup that would be completely lightning-proof (or as close as possible) would be to have all internal-external connections (phone, internet, etc) completely wireless, and use an independent generator for the power supply, surrounded by an extremely well-grounded cage of very conductive material capable of handling a large, direct strike without seriously compromising the cage structure (like thick steel girders), as well as good EMF shielding. Any plumbing facilities would have to be located outside the cage. Any spikes or surges coming from equipment inside the cage I'm not considering in this little mental exercise.

Of course, I would never need a setup like this, everything I have can be replaced. I'm just wondering if I've covered all the bases here to the point where if a very large bolt struck directly at the power lines connecting the supply and equipment inside the cage would be diverted by the cage and completely shunted off to ground? Because I feel that part of understanding how to protect reasonably well from surges is to understand what the perfect (or as close to it as can be) setup is, then I will be a step closer to grasping the whole picture here if how to get the most protection for my investment.

By the way, is it possible to shield from EMF pulses? I think it must be possible at least to some extent, but I'm not sure how. I remember hearing that a large nuclear warhead exploded too far above a city to cause much damage would, as a result of the EMF pulse, fry pretty much every electronic device in the city.

What are switching transients? From the context I'm thinking machinery or equipment that uses a lot of juice switching on and off relatively near my location and on the same grid?

The guy who fixed my furnace (I kept the circuit board he replaced and you can see the little burn mark) said that he had a nearby strike that fried some stuff in his house but apparently left the big-screen TV unharmed. However for six months after that, they kept having appliances fail for no apparent reason, and it was driving him nuts. Then one night he heard a noise from the TV (I think he might have said it was OFF at the time?) and saw smoke come out of it. The TV was fine, but a couple more appliances went belly-up after that. He figured out that the TV was periodically sending relatively large surges out even though it worked fine.

Weird, eh?

You are probably thinking of the Faraday Cage, which is to completely surround the protected room with conductive metal including the smallest openings. Theoretically, the inside of the cage will not be affected by external fields. If the conductor is thick enough (copper plate), the inside of the structure will be completely protected from lightning. Of course provisions must be made for entry of power, RF connectors, and other signal circuits. These will require further protection. Needless to say, this is usually impractical and expensive.

This is why people driving around in cars are generally protected from lightning strikes as they are at least partially surrounded by conductive metal. Any direct strike on the car would be conducted by the frame and through the tires to ground.

People who work in metal skyscrapers are generally protected from lightning. It is said the Empire State Building takes dozens of lightning hits each year.

Shielding for electric fields is easy. All one needs is a thin layer of metal.

Shielding for magnetic fields is a bit more difficult. It can be done with something called high mu metal, which for all practical purposes is a sheet of heavy cast iron metal.

Beachcomber

Minimum for a protector is 1000 joules and 50,000 amps. Multiple times posts - that was the numbers you read in Lowes two days ago on boxes. Typical lightning strike averages 20,000 amps. Therefore a protector that is double or more is sufficient. Again, you have known what numbers to read so many posts ago. (BTW, as joules increase, a protector's life expectancy increases exponentially. I was wating for you to go to Lowes so that that sentence could be appreciated.) Those numbers are printed on each protector's box. No insult. Either do that or learn little useful from this thread.

How does a Franklin lightning rod work? Lightning seeks earth ground. Either lightning finds earth ground through things you treasure, or lightning finds earth via a non-destructive path. Lightning rod connects a direct lightning strike to earth, shunts lightning to an earth ground, and leaves no damage. All effective lightning protection systems only do that - as posted repeatedly. That is it. Notice that E=IR appears nowhere - is irrelevant. This paragraph says, but again, everything that an effective protector does. It's that complex.

Lightning strikes a utility pole down the street. That is a direct strike not to a roof. That is a direct strike to household appliances. Same concept. Either lightning finds earth ground destructively via appliances OR lightning finds earth at the service entrance - via a 'whole house' protector thereby causing no damage.

Earthing is what effective protector does. If we attempt to stop or block lightning, then damage results. Stopping or blocking lightning created a melted CB antenna coil.

Testing earth ground reports little useful information. Inspect earthing and wire connections to earthing. If not, then hire assistance - the electrician. That earthing must meet post 1990 code. That ground rod must be as long as one sold in Home Depot. IOW that rod must be solidly in earth; not move horizontally or vertically as would be obvious once you hold that rod in Lowes. Earthing should exceed code by requirements defined previously: 'less than 10 feet', separated from other non-earthing wires, no sharp bends or splices, etc. Conditions that exceed code - make earthing even better - were listed previously. But again, these numbers mean nothing until your hands get dirty in that store.

Is that sufficient for earthing a commercial radio station? No. Not even close. But then you are not earthing every lightning strike that can ever exist. If earthing is upgraded to post 1990 electrical code, then major protection exists. If someone installs a 'whole house', then that is a massive protection improvement.

Why is a Ben Franklin lightning rod complex? A concept so simple as to be taught in 2nd grade science. 'Whole house' protector does same. Other simple requirements exist such as post 1990 code requirements, routing wire as short as possible, etc. But a protector is nothing more than a connection to earth - as Ben Franklin demonstrated in 1752. A shunt mode protector is nothing more than a connection to earth - just like Franklin's lightning rod.

We could do additional things - more rods, a halo ground, Ufer ground etc - to make the system more effective. In fact, every new building should have an Ufer ground standard. We still don't build as if transistors exists. So we install an earthing electrode. We can do more - a protector of more joules - to expand protector's life expectancy.

You suffered surge damage and need effective protection. You currently don't even know if the building has an earth ground. Therefore anything done, as defined in above posts, is a massive protection improvement. Even that utility earth ground - inspecting the primary protection system - may result in major lightning protection. As soon as you saw pictures from

, then you were outside looking? Why not? Dirty feet are required to comprehend what was posted.

There is nothing to test. We install what is necessary. If damage occurs later, we enhance an earthing system or we locate an incoming conductor that entered building without being earthed. IOW we learn from mistake. Lightning damage is failure directly traceable to a human. Humans only learn from mistakes. Unfortunately, only useful testing is lightning - destructive testing. So we do the best we can. If that is not sufficient, then we learn from a mistake and make that system better. But in most cases, a 'whole house' protector and earthing to conductive soil makes surge damage irrelevant. A solution that costs so little and yet is a massive improvement.

I am honest - not politically correct. You will never understand what was posted without visiting Home Depot. All necessary numbers have been posted repeatedly: joules, amps, 8 foot rod, 'less than 10 foot' connection, and post 1990 code. E=IR reports nothing useful. If you did not hold that ground rod in your hands, then you are not yet ready to reread everything posted. Where is that paper with every number from every protector's box? What did that wire clamp feel like? What does a 6 AWG wire look like? What were prices? Without dirty hands, then information posted here will remain confusing.

If you th>> Read numbers yourself rather than posting speculations.

The above is utter rubbish. Impedance is not a source of energy - it won't increase the energy content by the smallest fraction, let alone massively. Either the statement does not convey what you have in mind, or what you have in mind is horribly wrong.

Ed

As a source of information I really recommend

by the Institute of Electrical and Electronic Engineers.

Another good source is

by the US government - National Institute of Standards and Technology.

Both guides were intended for wide distribution to the general public to explain where surges come from (lightning and switching) and how to protect against them. The IEEE was targeted at people who have some (not much) technical background.

-------------- Nuclear bombs produce EMP - electromagnetic pulse. The military protects against it, but it is not practical for anyone else. The military uses screen rooms - Faraday cages or special protection for field equipment. EMP is very high energy which is picked up by wiring over a very wide area. The EMP produces a high voltage pulse on wiring which is particularly hazardous to transistors. The wiring can be inside computers and under the hood of cars (surge protectors won't help). Old cars with ignition points and vacuum tube radios may survive.

(Lightning also produces EMP but the energy is far lower and range very limited. It is particularly an issue for an equipment room next to a tower antenna.)

bud--

What happens when a constant current source feeds increasing impedance? Increased energy builds in that high impedance device. What happens when lightning is blocked by larger impedance such as a CB coil? CB coil melted. Melting occurred because impedance in a constant current was excessive.

Basic electrical concepts demonstrate that lightning surges are not stopped, blocked, or absorbed. Basic electrical concepts demonstrate why Franklin's lightning rods - a low impedance path to earth - shunt lightning without damage. Protection is about a low impedance path to earth. No way around a principle demonstrated even 100 years ago.

Yes impedance is not a source of energy. But then no such claim was posted. > The above is utter rubbish. Impedance is not a source

Given that the neutral and ground are bonded at the panel within inches of there the surge handling gadget is, so long as all metal in the house in bonded to that point, it doesn't really make much difference how "good" you ground is.

Basically, it "sh*t" happens, your wiring system voltages might bounce about "true" ground but the voltages between conductor pairs would still be limited.

published by the Institute of Electrical and Electronic Engineers.

Thanks!!

In another cited URL (from Bud), two TVs plugged into a power strip protector are at 8000 volts when the other end of that same safety ground wire in breaker box is only at zero volts. Why? Because wire has impedance. TV end of that wire is at 8000 volts whereas breaker box end is at near zero volts. Wire is not a perfect conductor. Electricity at both ends of a wire is not same because wire is not a perfect conductor. How do we get that 8000 volts on TV reduced? That plug-in protector must be near zero feet to breaker box and earth ground. Makes no difference here that neutral and safety ground wires are bonded in breaker box. Distance of wire determines impedance. Meanwhile those two TVs at 8000 volts find other destructive paths to earth because plug-in protector was too far (8000+ volts) from earth ground.

Neutral and safety ground bonded together in breaker box tells us nothing. That junction must make a 'less than 10 foot' connection to earth. What makes a breaker box 'whole house' protector so effective? Because it connects where neutral, safety ground, and earthing ground all connect AND because that earthing meets post 1990 code requirements, AND because that earthing wire connection is low impedance - short - 'less than 10 feet'.

Sh*t happens because a human failed to properly install earthing - failed to learn what was well understood even 50+ years ago. No damage from direct lightning strikes is routine if lightning is properly earthed before entering a building.

Is all metal properly grounded short to that AC electrical box? Don't forgot other conductors to earth such as wall paint, linoleum tile, concrete floors, baseboard heat pipes, etc. Those too must be bonded short to that breaker box. If not, then 8000 volts on those two TVs have other and destructive paths to earth. Just another reason why earthing is the most critical component in any protection system. No earth ground means no effective protection.

John Gilmer wrote:

The link at

is a guide published by the IEEE, and is a link posted by you, plainly describes the operation of a multiport plug-in surge suppressor as clamping all power and signal wires for a device to a common ground at the surte suppressor. That protects the TV. Other TVs may need their own multiport surge suppressor. They work primarily by clamping, not earthing. The IEEE says plug-in surge suppressors are effective.

The NIST at

says plug-in surge suppressors are effective. You have still not provided a link to a reputable source that says plug-in surge supppressors are not effecive.

I basically agree.

bud--