All references are based on the 2020 edition of the NEC.
Rogue RV Park Wiring
Thanks to Mike Allen from Erwin, Tenn., for sharing this photo with us. He discovered this mess when his company was asked by a local excavating contractor to “assess the electrical supply to an existing RV park in the mountains of Upper East Tennessee.” Generally speaking, protecting 10/2 UF cables with a 200A overcurrent device would typically be a violation of Sec. 240.4(D)(7). These cables should be protected at 30A maximum unless otherwise permitted in Sec. 240.4(E) or (G). Section 240.4(E)(3) permits tap conductors to be protected per Sec. 240.21. If these wires are considered feeder taps, Sec. 240.21(B)(5)(2) permits them to terminate at a single circuit breaker or fuse that limits the load to the ampacity of these tap conductors. Mike did not mention whether each of these wires was connected to overcurrent devices in RV site equipment at the load end of the circuits, so we can’t determine if these wires are considered properly protected against overcurrent. One thing I am certain about is the number of conductors landed in each terminal is a violation of Sec. 110.14(A). Terminating more than one conductor in a terminal is only permitted if the terminal is specifically identified for that purpose.
Vineyard Violations
EC&M reader Brian shared this photo with us. He says, “While walking along a vineyard road in Northern California, I noticed some conduit becoming exposed along a roadbed. The conduit looks to be 1½ in., and the conductors might be #10. Sure wasn’t buried to the required depth even when installed!”
Direct buried conduits and raceways must be installed deep enough to meet the minimum coverage requirements outlined in Table 300.5. Column 3 of this table provides the minimum cover required for nonmetallic raceways, including rigid PVC conduit. Under streets, roads, alleys, parking lots, and driveways, the minimum depth of cover for rigid PVC conduit is 24 in. This raceway appears to have been buried only a few inches deep. The tire impressions in the dirt indicate a tractor or large truck travels along this roadway and has finally worn down the dirt enough to destroy the raceway and damage the enclosed conductors. This raceway will need serious repair work, and new conductors will probably need to be pulled through the raceway to make this safe again. Perhaps the raceway could be encased in concrete, buried deeper, or re-routed to provide some much-needed protection.
