17% More Reliable Grounding Solution Video Series
by Jeff Jordan, MBA, PE
Product Manager, Copperweld Power Grid
In this video series, Copperweld’s Jeff Jordan explores trends, technologies, and challenges to conventional thinking in the field of high voltage grounding conductor selection. Each episode attacks a relatively complex or unfamiliar topic, explaining it in practical terms. In the course of ten episodes, a novel method for quantifying the expected reliability of copper and other grounding conductors is described, as a complement the formula for substation design in IEEE Std 80. The series takes the position that selection based on current carrying capability, alone, ignores the likelihood of the conductor being missing or broken when it is needed, years—or even decades—after installation.
Part 1: What is Grounding
Grounding is the name we give to the protective circuit that conducts lightning and power line faults safely into the wet conductive earth, the ground.
Part 2: 17% More Reliable
Copperweld copper-covered steel (CCS) is a superior grounding solution, 17% more reliable than standard copper in electrical grounding applications.
Part 3: Problems with Std 80
IEEE Std 80 provides quantitative guidance on maximum fault current carrying capability, but only subjective guidance on equally critical reliability performance.
Part 4: Arcing is the enemy
Any lightning strike or a line to ground fault on the power lines will find a way into the Earth by the path of least resistance, even if it has to arc through the air to get there.
Part 5: Copperweld CCS in service 73 years
Less copper does not mean less reliable. This is a myth disproved by examples like the 73-year-old Copperweld Type A power conductor still in service at Dawson Public Utility.
Part 6: Visualization of reliability
A visualization of field failures using a normal distribution assumes that the sum of the reliable and unreliable grounding conductors will equal one, shown as the area under the curve.
Part 7: Defining unreliability
For a grounding conductor, unreliability is the sum of the probabilities of an incomplete past to ground caused by breakage, theft, corrosion, or wind fatigue.
Part 8: Scoring unreliability
Subject matter experts scored the chances of a copper grounding conductor being stolen any time within its 30-year expected service life at 10%.
Part 9: Quantifying the resiliency of CCS
For electrical grounding, this article defines Resiliency as the reliability improvement percentage divided by the standard reliability percentage (82%) of copper.
Part 10: Visualization of resiliency
Resiliency of grounding conductors can be visualized as the change in average service life caused by selection of a suitable material with fewer early field failures.