I really don’t understand where Erik gets the idea the grounding I did was extravagant. Its code??????? Go read NEC Article 250.
erik_squires said:
Extravagant is the difference between what the NEC would require (minimum 2) and what was installed.
@kingrex only installed one ground rod, 20ft long into the earth. He then tested the rod to soil resistance using the proper test equipment. kingrex met the requirements of 2020 NEC 250.53 Exception.
Exception: If a single rod, pipe, or plate grounding electrode has a resistance to earth of 25 ohms or less the supplemental electrode shall not be required.
Kingrex's use of the Cadweld System (Trade Name for a exothermic welding process) is unusual for a residential dwelling unit but it is a 100% solid conductivity zero resistance connection of the grounding electrode conductor to the grounding electrode, (ground rod). It will be that way forever... Can't say that about an approved ground rod clamp. Remember the connection is buried in the earth below grade. How often is the connection checked after it is installed?
FWIW The grounding electrode system primary purpose is for lightning protection. It is the foundation for a good system ground connection to earth for an electrical service.
The lower the soil to electrode resistance the faster a whole house SPD will divert a lightning transient to mother Earth.
Also worth noting 25 ohms is to high of a soil to grounding electrode resistance. IEEE (Green Book) recommends 5 ohm or less for commercial and industrial facilities. Lightning could care less if it's a residential dwelling.
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