NEC 2017 690.31(G)(3) Marking and Labeling Required
l raceways, boxes, trays, and covers with PV DC conductors must display “WARNING: PHOTOVOLTAIC POWER SOURCE.” Markings must be permanently affixed and visible after installation for clear identification.
Labels must be spaced no more than every 10 ft (3 m) along the wiring system. Markings must suit the installed environment—weather, temperature, and exposure conditions. Ensures quick recognition for maintenance, inspectors, and emergency responders, improving installation safety and NEC compliance.
