NEC Article 210.8 is the main rule for GFCIs. Other applications mandate the use of GFIs, such as, but certainly not limited to
555.9(B)(1)
525.23
511.12
625.22
647.7(A)
620.85
Article 680 coversPools, Fountains, and similar installations (drinking fountain is not included in the definitions of...
Be aware of what the National Electrical Code says in 300.3 Conductors.
(C) Conductors of Different Systems.
(1) 600 Volts, Nominal, or Less. Conductors of circuits rated 600 volts, nominal, or less, ac circuits, and dc circuits shall be permitted to occupy the same equipment wiring enclosure...
