148 doesn't play favorites: The code mandates that all metallic parts of electrical boxes must bond to ground—no exceptions for cabinet doors. Bottom line: That door is part of the enclosure. Skip the grounding, and you're gambling with safety. In factories, construction sites, and even commercial buildings, this question pops up all the time. For grounded systems, the NEC requires you to perform all of the following: electrical system grounding, electrical equipment grounding, electrical equipment. Safety Enhancement: Electrical bonding ensures all metallic components are at the same potential, minimizing shock hazards. Fault Current Pathway: Proper bonding provides a reliable path for fault currents, facilitating the operation of protective devices. 4 (A) (1) explains, electrical systems connect to ground to limit voltage imposed from lightning strikes, line surges, high-voltage crossovers and to stabilize voltage-to-ground under normal operation.
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