Grounding Conductor Sizing in Raceway

[Jody Boehs]

Hello,
I have a busway running through the plant I work at. We attach bus plugs to it as needed and as current capacities allow.
From said bus plugs we usually run a conduit to the desired drop location and pull in the needed wires.
In table 250.66, it says '2 or smaller' needs to have a #8 Copper grounding electrode conductor.
To me, this implies that if the ungrounded conductors are #8 or smaller, then the grounding conductor needs to be the same size as the ungrounded conductors, correct?
Or direct me to the correct table/article that clarifies what the grounding conductor size needs to be for smaller wires. I have been taught that on anything #8 or smaller, I am to use the same size of wire as the ungrounded conductors. But, now have someone saying something different and I need to clear it up.

Thanks in advance!

 

[david luchini]

Hello,
I have a busway running through the plant I work at. We attach bus plugs to it as needed and as current capacities allow.
From said bus plugs we usually run a conduit to the desired drop location and pull in the needed wires.
In table 250.66, it says '2 or smaller' needs to have a #8 Copper grounding electrode conductor.
To me, this implies that if the ungrounded conductors are #8 or smaller, then the grounding conductor needs to be the same size as the ungrounded conductors, correct?
Or direct me to the correct table/article that clarifies what the grounding conductor size needs to be for smaller wires. I have been taught that on anything #8 or smaller, I am to use the same size of wire as the ungrounded conductors. But, now have someone saying something different and I need to clear it up.

Thanks in advance!

See 250.122.

 

[Jody Boehs]

See 250.122.

Thank You! This clarifies what I need to know.

 

[tom baker]

Thanks for asking. We get a lot of “this is what I’ve been told”, often it’s good to step back and review the code.