The conic electrical grounding theory states that systematic electrical bonding and grounding applied outward from a vertex sited at the earth (or other conductive point) will create a strong grounding cone of protection (GCP) that isolates and shields the space within its boundary from the flux of electrical and magnetic currents, affording protection from dangers and annoyances commonly manifested as interference, flashover, electrical shock, and fire.
The facility grounding electrode system acts as the vertex of the grounding cone of protection from which extends outward and upward a cone of balanced, same-voltage shielding.
The grounding cone of protection extends upward and outward from the vertex to the base, which serves as the upper boundary. More than one GCP is common at a facility.
Electrically, all GCPs share points of connection for their vertices somewhere along the primary GCP. All separate GCP vertex points, or vertices, will have a direct electrical connection to each other that traces back to the primary GCP and the facility GES.
Primary Grounding Cone of Protection
A primary GCP is customarily the outermost GCP identified at a facility. It has the GES as its vertex, and the facility roof as its base.
Roofing and wall materials are commonly not conductive, so gaps within the primary GCP are to be acknowledged and mitigated by thorough pre-construction planning if more complete protection is desired. For example, a lightning protection system or conductive materials at the roof or exterior walls could be used in the construction and affirmatively bonded to the primary GCP.
An exterior integrated systems bonding point commonly rides the primary GCP between the ESE and GES.
Secondary Grounding Cone of Protection
Secondary GCPs are commonly found indoors and may begin its vertex at a sub-panel downstream from the ESE, and possibly at an interior telecommunications closet or panel box.
Tertiary Grounding Cone of Protection
A tertiary GCP is commonly found indoors and may begin its vertex at a multilink power outlet strip that includes grounded AC power and telphone or cable television receptacles as well. An indoor ISBP is another example of where to identify the beginnings of a tertiary GCP.
Summary
The conic electrical grounding theory introduces the grounding cone of protection (GCP), which has gaps at its base and along its exterior. The cone requires strengthening in order to reduce hazards.
The grounding electrode system acts as the vertex of a facility’s grounding cone of protection. This is one example of a primary GCP. Secondary and tertiary GCPs can exist further within the primary GCP.
