Radio 300

• Section 1: Introduction
• Section 2: Definitions of Special Terms
• Section 3: References
• Section 9: Grounding Methods for Electric Supply and Communications Facilities

Part 1: Rules for the Installation and Maintenance of Electric Supply Stations and Equipment

• Section 10: Purpose and Scope
• Section 11: Protective Arrangements in Electric Supply Stations
• Section 12: Installation and Maintenance of Equipment
• Section 13: Rotating Equipment
• Section 14: Storage Batteries
• Section 15: Transformers and Regulators
• Section 16: Conductors
• Section 17: Circuit Breakers, Reclosers, Switches, and Fuses
• Section 18: Switchgear and Metal-Enclosed Bus
• Section 19: Photovoltaic Generating Stations

Part 2: Rules for the Installation and Maintenance of Overhead Electric Supply and Communication Lines

• Section 20: Purpose, Scope, and Application of Rules
• Section 21: General Requirements
• Section 22: Relations Between Various Classes of Lines and Equipment
• Section 23: Clearances
• Section 24: Grades of Construction
• Section 25: Loadings for Grades B and C
• Section 26: Strength Requirements
• Section 27: Line Insulation
• (Additional sections on overhead rules, including guys, supports, etc.)

Part 3: Rules for the Installation and Maintenance of Underground Electric Supply and Communication Lines

• Sections covering purpose, scope, underground construction, cables, equipment, and installation requirements.

Part 4: Work Rules (Rules for the Operation of Electric Supply and Communications Lines and Equipment)

• Sections 40–44: Covering employer and employee rules, including approach distances, fall protection, and arc flash requirements.

Appendices and Annexes

• Appendix A: Uniform system of clearances
• Appendix B: Uniform clearance calculations
• Appendix C: Example applications for loadings
• Appendix D: Practical approaches to reducing overvoltages
• Appendix E: Bibliography
• Annex 1: Metric tables and figures
• Annex 2: Letter symbols for units
• Index

The NESC also includes numerous figures, tables (e.g., clearance tables like 232-1, 235 series, loading tables 250–253, strength tables), and supporting rules within each section.For the full document, including exact rule numbering and details, refer to the official IEEE publication (available via IEEE Xplore or purchase). The structure has remained consistent across recent editions, with updates primarily in content (e.g., new rules for energy storage, distributed generation, and wireless attachments in 2023).