Article 501.10(A)(1) allows PVC conduits no less than 24" below Class 1 Division 1 areas where enveloped in at least 2" of concrete. There are exceptions to the concrete in Fuel Dispensing and Bulk storage. Class 1 Division 2 allows all methods of C1D1 and does not modify the requirement. We have a new RNG facility in which we are running a number of PVC conduits into a C1D2 area. The mechanical/structural engineering firm has the lead and has indicated that concrete encasement is not necessary since the only hazardous substance is lighter than air and the area below the classified area is not classified. Therefore the installation would be more of a boundary crossing scenario. They indicate they have done numerous installations and none have required encasement. This does seem reasonable since there's nothing that would seep down to the conduit. However, that is not exactly what the code says. Am I missing something? I'd rather not require the concrete encasement but I feel compelled based on strict interpretation of the NEC.
PVC Under Class 1 DIvision 2 Area
- Thread starter MartStod
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