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Thursday, March 9, 2017
Question:
I have a grounding issue that I am in discussion with the AHJ. I ran a 3 wire 240 volt Feeder to a barn (no equipment ground) 460 feet from the residence. Drove a ground rod and connected it to the panel and didn't Bond the grounded conductor(neutral) to the grounding electrode. The inspector said that I needed to run a grounding conductor with the Feeder. I say that 250.32A gives me the choice to run this wire or drive a ground. What do you think and why?
Mark Yates
A
Answer:
Hey Mark thanks for your question. The inspector is correct. An equipment grounding conductor is required to be installed and be connected to the disconnecting means and the grounding electrode(s) at the barn as stated in 250.32(B). Section 250.32(A) requires a grounding electrode system but does not allow a grounding electrode(s) to be used in place of an equipment grounding conductor. This is further supported by the last sentence of 250.4(A)(5). In the situation you describe there is no effective ground fault current path from the residence to the barn.
Also a single ground rod must be supplemented by another electrode, which could be a second ground rod, as stated in 250.53(A)(2) unless you meet the 25 ohm resistance value in 250.53(A)(2) Exception
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