While I do appreciate that a good ground is essential, and that whole-house protection is the way to go, in practice, where have you ever seen a home with a ground electrode driven 130' into the earth? It's usually a 4 or 6' electrode. Where has an electrician verified the ground conductor's resistance to ground? Nope, not done.
First, earthing must meet
and exceed electrical code requirements. Nobody needs a 130 foot ground. Since in most cases, two 10 foot ground rods are more than sufficient. 4 or 6 foot ground rods are a code violation. And also insufficient for surge protection.
Important is the single point ground. Then earth can even rise to 10,000 volts. And nothing inside sees any voltage. These well proven concepts are called equipotential and conductivity. And are introduced (without describing them) in the case studies.
Case studies demonstrate that defective grounds violated those principles. In one case, the radio station people even disconnected grounds on a myth that grounds were attracting lightning. How did they stop all surge damage? They simple fixed the earth grounds. Created single point grounds. Wasted no time and money on more protectors. Then all damage stopped.
Unfortunately one gets caustic when these well proven concepts contradict popular myths. He never did this stuff. I did. Earthing for homes is easily established to make direct lightning strikes (and the many lesser transients) irrelevant. So that 99.5% to 99.9% of surges do no damage (numbers from the IEEE). One can add power strip or UPS protectors for maybe an additional 0.2% protection.
Protection is also a function of geology. In one home, a 'whole house' protector was properly earthed. And they still suffered damage. Lightning is a connection from cloud to earth. That current continues maybe miles through earth to distant earthborne charges. As long as that path does not pass inside a house, then no damage. But appliances were still damaged.
Eventually, a vein of graphite was discovered behind the house. A best path was incoming on AC mains, ignore the service entrance earth ground, pass through appliances, then connect to that graphite vein.
As usual, the solution is found in better earthing. A ground wire loop around the building connected to the service entrance (single point) earth ground. Now equipotential was made better. Earth beneath the entire house was one big single point earth ground. Better equipotential (and conductivity) was created. Now a best connection to distant earthborne charges was incoming on AC mains, through a 'whole house' protector, into the ground wire loop, to a graphite vein, and to distant charges. Now the path remained outside the building. Protection is always about the earthing.
This was a rare failure. Most homes are sufficiently earthed by two ten foot ground rods. But homeowners that want even better protection use this ground loop or another superior earthing method - Ufer grounds. Because surge protection is always defined by the connection to and quality of single point earth ground. And not by protectors.
2) Surges are not voltage. If its current is properly connected to earth, then a lightning strike creates near zero voltage. Voltage only exists when something foolishly tries to stop a surge (ie an adjacent protector or UPS). Those adjacent protectors will absorb how much energy? Hundreds of joules? A protector adjacent to an appliance can only block or absorb a surge. Increasing voltage. Meanwhile, typically destructive surges are hundreds of thousands of joules. Creates near zero voltage when the connection to a better earth ground is low impedance (ie 'less than 10 feet').
3) Once permitted inside, that current will hunt for earth ground destructively via appliances. A typical surge on AC mains is incoming to every appliance. Are all appliances damaged? Of course not. The one or few damaged appliances must also have an outgoing path to earth. Damaged appliance have both an incoming and outgoing path. Then those appliances act like a 'whole house' protector to protect other appliances.
Informed consumers spend maybe as little as $50 for an earthed 'whole house' protector. So that no appliance need be damaged. So that direct lightning strikes (when properly earthed) do not even damage the protector. Then near zero voltage exists from a surge. A voltage that remains well below what all appliances are designed to withstand without damage.
4) Plug-in protectors will not even mention earth ground. Since that would harm sales. Informed consumers earth a 'whole house' protector. Protectors are simple dumb science. The 'art' of protection (as made obvious in so many case studies) is what does the protection - single point earth ground. That house adjacent to a graphite vein is one example of the "art".
