250.102(C)(1): Bonding Jumper

Grounded Conductor, Main Bonding Jumper, and System Bonding Jumper Sizing.

Source: NEC 2020

The Math Shortcut

Use the Grounding Calculator

Service Conductor Size (Cu)Service Conductor Size (Al)Bonding Jumper (Cu)Bonding Jumper (Al)
2 or smaller1/0 or smaller86
1 or 1/02/0 or 3/064
2/0 or 3/04/0 or 250 kcmil42
Over 3/0 - 350Over 250 - 50021/0
Over 350 - 600Over 500 - 9001/03/0
Over 600 - 1100Over 900 - 17502/04/0
Over 1100Over 175012.5% of Phase Área12.5% of Phase Área

Related NEC Tables

Table 250.66: Grounding Electrode (GEC)Table 250.122: Equipment Grounding (EGC)

Professional Usage

This data is provided for informational purposes only. Always verify with the latest edition of the National Electrical Code (NFPA 70) and consult with a licensed electrical professional or AHJ (Authority Having Jurisdiction) before performing any electrical work.

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