Is PVC schedule 80 non concrete encased an acceptable wiring method? This is a bulk storage plant. I would be coming from a cable tray running underground to a motor at a tank. I would emerge last 2' of the run with RGC and a seal at each end of run. I believe I am good as permitted by 515.8(A). I am confused with 515.4 and 515.7 does above mean "over the top of"?