Q. Which of the following methods for connecting grounding and bonding conductors to equipment is the only one not permitted by the NEC?
Green-colored “tapcon” self-tapping concrete anchors drilled directly through a metal box (no threads engaged), and used to connect the grounding and bonding conductors, are not intended for, nor are permitted for this use (see 250.8). The use of sheet metal screws is also not permitted for this use.
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