Mike Dolt Enterprises
Mike Dolt Enterprises
User: charlie b, Location: Lockport, IL
Asked on: Thursday, April 28, 2011 at 11:28 am EDT
Answered on: Tuesday, May 14, 2024 at 4:44 am EDT
Question: I am separating this issue from a previous thread of mine. Consider the following:? Pour a small concrete pad (3? x 5?), some distance away from a building.? Place on the pad a manufactured skid that includes a couple pumps and some valves, pipes, and motor controllers.? Provide power to the skid via a single branch circuit from the nearby building.Question 1: Does this meet the definition of ?structure,? per NEC article 100?Question 2: If the answer to #1 is ?yes,? then do the requirements of NEC 250.32 apply (i.e., is a grounding electrode required)?For my part, I have never installed ground rods near skid-mounted water processing equipment. But the equipment has always been inside the same building as the source of power. So this is a new territory for me.
Question 1: Does this meet the definition of "structure," per NEC article 100?
Yes, it does. NEC Article 100 defines a "structure" as "that which is built or constructed, an edifice or building of any kind, or any piece of work artificially built up or composed of parts joined together in some definite manner." The concrete pad and skid, which are built up and joined together, meet this definition.
Question 2: If the answer to #1 is "yes," then do the requirements of NEC 250.32 apply (i.e., is a grounding electrode required)?
Yes, they do. NEC 250.32 requires grounding electrodes to be installed for all structures that are "likely to become energized." This includes any structure that contains electrical equipment, such as the skid in this case. The skid contains pumps, valves, pipes, and motor controllers, which are all electrical equipment. Therefore, a grounding electrode is required.In addition, the skid is not located within the same building as the source of power. This means that it is not protected by the building's grounding system. Therefore, a separate grounding electrode is required for the skid.
Conclusion:
Yes, the concrete pad and skid meet the definition of "structure" per NEC Article 100. Yes, a grounding electrode is required for the structure per NEC 250.
32. Flag for review