Article 300.50(A)(1) and (2) states that buried cable over 600V must be either Shielded, metal sheathed or installed in RMC, IMC or PVC encased in concrete. At least that is my interpretation. Working on Photovoltaic, (PV), systems with a DC rating of 1000V, it is not uncommon to see non-shielded/sheathed 1000V PV cable direct buried. In fact, I cannot find PV cable that is manufactured with a metal covering for this application. I contacted a cable manufacturer and was told that since article 690.31 states in part that ....all other wiring systems and fittings specifically intended and identified for use on photovoltaic arrays shall be permitted, that this allows the use of direct buried unshielded/sheathed PV cable at 1000V that they manufacture since they are listed for and specifically intended for use on pv arrays.
Any other opinions out there?
Any other opinions out there?