NEC Code

NEC 250 Grounding & Bonding at a Glance

How the grounding electrode system, GEC, main bonding jumper, and EGC all connect -- and why they're sized from two completely different tables.

Art. 250

Grounding & Bonding System NEC Article 250 Grounding Electrode System Ufer, water pipe, rod, ring GEC sized from Table 250.66 Main Bonding Jumper SERVICE ONLY -- one bond point Service Neutral (grounded conductor) bonded to ground ONLY here EGC sized from Table 250.122 (by OCPD rating, not GEC table) Subpanel (feeder) 4-wire feed -- neutral and ground bars stay SEPARATE Never re-bond neutral to ground downstream of the service A second bond point creates a parallel path -- neutral current can flow over grounding conductors, metal piping, and equipment enclosures.
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