| The OP is pretty clearly not in the US and is not subject to the NEC. And just because the NEC doesn’t say you need to mitigate touch potentials for a specific installation doesn’t mean that you shouldn’t. The NEC is just a bunch of requirements, not a complete guide to building safe, high quality electrical installations. And there appears to be plenty of guidance from IEEE about this if you feel like paying for a copy of the standard: https://store.accuristech.com/ecia/products/preview/2085911 The NEC does have plenty to say about grounding for purposes of reducing potential differences in other (non-solar) installations, though. Swimming pools are a notable example (with no specific requirement IIRC to connect the fancy bonding to the Earth at the pool, but a typical concrete pool with NEC-mandated bonding is likely an excellent connection to the local soil). Amusingly, an inspector could plausibly require an “equipotential plane” per NEC 547.44 if the solar array is accessible to livestock. Alternatively, from first principles: suppose you are standing with bare feet on wet soil 100 meters from a building. That building has a very nice ground rod array, giving an impedance of 50 ohms from the building’s ground to your feet. Now take a long wire that is insulated except at the ends, connect one end to the building ground, and firmly hold the other end in your hand. How do you feel about this situation? You have a nice wire loop, potentially with area on the order of 100m^2, containing your heart. It can inductively couple to time-varying magnetic fields (e.g. the fields around nearby transmission lines) and it can capacitively couple to other conductors. It can resistively couple to power lines with multiply grounded neutral or to electrified railways or to nearby buildings with old-style (earlier NEC revisions) shared neutral/ground feeds And lightning can strike the array. I think it would be wise to ground the array to earth to reduce the potential difference between the frame and earth. |