In this question, someone has a desk lamp with power totally exposed on metal parts. You also have installed overhead lighting on open rails doing the same thing.
What does NEC say about the maximum voltage permitted on such installations?
I am interested in fixed installations (not cord-and-plug) which are readily accessible, e.g. Low hanging low-voltage lighting that you could reach out and touch.
I am also interested in the outdoor rules, because my nefarious plan is to use the racks which hold up solar panels to carry the current from the panels, so the racks become massive feeder wire that lets me keep voltage low. Some of the panels will be on the ground.
Is the maximum voltage different for AC versus DC? If AC, does it mean RMS (the normal way AC is measured) or peak (1.4x more)?