There are a number of different grounding electrodes in use today. They are the standard driven rod, advanced driven rod, grounding plate, concrete encased electrode (sometimes called a Ufer ground), water pipes and the electrolytic electrode.
Many people are concerned that bonding the steel rebar in concrete may lead to cracking of the concrete due to thermal heating. It is a very counterintuitive concept, but it’s actually the exact opposite.
Ground Fault Protection systems are very sophisticated devices, often with many variable settings to “Dial-In” the specific requirements needed for your site. Also, the reliability of the GFP systems depends on many factors beyond the proper settings on the device.
The statement saying not to use with a power cord, has more to do with legal issues than with an electrical issue. However, there is a less than 1% chance that an issue could occur: Take an example of a construction foreman (or forewoman) working at a busy job site.
Herd animals that gather in groups are typically killed not by a direct lightning strike, but by the current flowing through the ground from the strike. What happens is that the lightning strike often hits a tree or the ground near where the animals are gathered and the electrical current then spreads along the surface of the ground and shocks any people or animals in the vicinity of the strike. Electrical current literally goes up one leg and down the other back into the ground. Eventually, the current dissipates as it flows further and further from the strike point.
1. The airplane is properly bonded from tip to tip and has an extremely low difference in potential from any given point in the plane.
2. The airplane is not properly bonded and has large resistances from front to back and side to side.