Agricultrual Buildings Grounding

[Bcornell377]

Hello I have a question from the 2008 NEC on 547.9B(3) in that when installing a grounding electrode(ie ground rod) in a separate building with an equipotential plane, in my mine this would change the values of the plane. Being that all energy from stray voltage issues should be sent back to the source instead of finding a path thru the ground rod if there are any they maybe come present. Maybe I am just over thinking this any comments will help thank you for the time.

 

[kwired]

Hello I have a question from the 2008 NEC on 547.9B(3) in that when installing a grounding electrode(ie ground rod) in a separate building with an equipotential plane, in my mine this would change the values of the plane. Being that all energy from stray voltage issues should be sent back to the source instead of finding a path thru the ground rod if there are any they maybe come present. Maybe I am just over thinking this any comments will help thank you for the time.

Equipotential plane and grounding electrodes serve different purposes do not confuse one with the other or consider one to be supplementing the other, though it may actually do so to some extent.

Equipotential plane is for bringing items that can be touched simultaneously to the same potential, regardless of what the voltage to true earth ground may be, so that when those items are being touched there is no potential between them.

Grounding electrodes are primarily for discharging surges from lightning and to provide a reference to earth, but when we have a grounded system conductor that carries current in normal operation that means there likely will be some voltage drop on the grounded conductor and this will cause voltage between this conductor and everything bonded to it and true earth, this is number one source of "stray voltages"