Table 300.5 Concrete Cap

[Kisi]

For Table 300.5 - is there an hierarchy of "importance" for the locations listed in the left column? Pretend you are installing PVC conduit under a parking lot...would the 24" (from row five) be absolute or does the second row (2" thick concrete cap) add a layer of protection and reduce the burial depth to 12"? The NEC handbook shows a great picture in 300.6 and 300.10 showing the lesser depth when there is a concrete cap, but is drawn specifically for UF cable and a residence. Can we extrapolate the same depth reduction applies to all the rows, even a parking lot? I've read and searched and there's lots of opinions so please clarify intent (if possible). Thanks!

 

[infinity]

The word trench doesn't mean under a parking lot. Parking lots must conform to the 24" burial depth. A trench through dirt with a 2" concrete cap would lower you from 18" down to 12".