Isolated Grounding Conductor

[rdjohnson]

Cany anyone tell my why an electrical grounding system for pipeline related facilities would be designed utilizing insulated grounding conductors? This is not an isolated grounding system for electronics. This is the main electrical grounding system for vessels, junction boxes, equipment, etc. which is ultimately tied to numerous ground rods. Is it meant to preserve the cathodic protection system on the piping somehow? If so, how can that be effective when the grid ultimately goes to ground at the grounding rods? Any help or comments would be appreciated.

 

[jbartos]

Suggestion: In many instances, the ground conductor is insulated to meet the color requirement by the electrical safety codes, e.g. green color. Ultimately, the bare copper conductor might be painted green. Also, the insulated ground conductor with current carrying conductors tends to provide an extra separation from those current carrying conductors.

 

[jghrist]

Probably to avoid galvanic corrosion of the pipeline. Steel (and galvanizing) is sacrificial to copper so the grounding is probably confined to isolated ground rods or grids away from the pipe or where the pipe can be more readily protected.

 

[busbar]

In cathodic protection, the intent is to minimize deterioration of metallic vessels in contact with soil. Somewhat like ground-electrode resistance, electrical characteristics change seasonally and over longer intervals.

Besides conductor attachment, certain sections may also be electrically isolated to more effectively monitor and maintain control of corrosion.

Specific levels of direct current is “forced” into the buried metallic components and sacrificial electrodes. Contact points of the vessels and other test electrodes are wired to test pedestals that allow periodic electrical measurements with portable instruments, for cost-effective supervision of changing, unavoidable and partially intentionally offset electrochemical effects.