Core TradesQuestion 81 of 700
A subpanel is fed from the main service panel in a detached structure. In a modern installation, the neutral (grounded) and equipment grounding (ground) conductors at the subpanel must be:
a.Kept separate, with the neutral bus isolated from the enclosure
b.Bonded together at the subpanel
c.Both left floating
d.Connected only through the metal conduit
Explanation
At a subpanel the neutral and ground must be kept separate, with the neutral bus isolated from the metal enclosure, so normal neutral current does not flow on grounding conductors and metal parts. Bonding neutral and ground is done only at the service disconnect, not at downstream subpanels.
Law Reference: 2025 CA Electrical Code (based on NEC)Practice all 700 questions free — no signup required.
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