Inspection of a Newly Installed Grounding Electrode System
An inspector is reviewing a new service installation. The grounding electrode conductor (GEC) is 6 AWG copper, run from the service panel to a ground rod 25 ft away. The rod is a 5/8 inch × 8 ft copper-bonded rod. The soil is rocky and dry. The installer drove the rod vertically but hit rock at 6 ft and cut off the top 2 ft to make it fit. The GEC is run in PVC conduit and bonded to the panel enclosure. The inspector must determine if the installation complies with NEC Article 250.
1. What are the code violations in this grounding electrode installation?
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Violations:
- The ground rod must be at least 8 ft in length and driven below permanent moisture level. Cutting off 2 ft leaves only 6 ft, violating NEC 250.53(G).
- If the rod cannot be driven 8 ft, it must be buried horizontally at least 2.5 ft deep, or another electrode method used.
- The GEC size: 6 AWG copper is permitted for a 100 A service, but if the service is larger, it may be undersized. The inspector must verify service size.
- A single rod must be supplemented by an additional electrode unless it has a resistance to ground of 25 ohms or less (NEC 250.53(A)(2)). The installer did not provide a supplemental electrode.
- The GEC must be continuous and not spliced; running through PVC is acceptable if properly bonded.
2. The installer argues that the rod is still in contact with soil and the system works. How should the inspector respond, and what corrective action is required?
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The inspector should explain that code compliance is not based on whether the system 'works' but on the minimum requirements for safety and durability. A 6 ft rod in rocky, dry soil is likely to have high resistance and may not provide a reliable ground path. The corrective action is to install a new 8 ft rod, either driven fully or buried horizontally, and to add a supplemental electrode (e.g., a second rod at least 6 ft away) unless a 25-ohm resistance test is performed and passes. The inspector should not accept the cut rod.