Article 110 – General Requirements for Electrical Installations

Purpose

Article 110 of the National Electrical Code® (NEC®) outlines the fundamental safety requirements for all electrical installations.

It ensures that equipment is installed, maintained, and operated safely, reducing risks of shock, fire, or mechanical failure.

Key Areas Covered

1. 110.2 – Approval All electrical equipment must be approved by the Authority Having Jurisdiction (AHJ) or tested by a recognized laboratory.
2. 110.3 – Examination, Identification, and Installation
   • Equipment must be listed and labeled for its intended use.
   • Follow manufacturer’s installation instructions for safety and code compliance.
3. 110.12 – Mechanical Execution of Work Installations must be neat, secure, and protected from physical damage. No sharp bends, loose connections, or unused openings left unsealed.
4. 110.14 – Electrical Connections
   • Terminations must ensure mechanical strength and proper conductivity.
   • Use connectors compatible with the conductor material (copper or aluminum).
   • Torque settings must meet manufacturer specifications.
5. 110.26 – Working Space Around Equipment
   • Maintain safe access and clearance around panels, disconnects, and service equipment.
   • Typical clearance: 3 feet (0.9 m) in front of live parts, and at least 30 inches (762 mm) wide.
6. 110.27 – Guarding of Live Parts
   • Exposed energized components must be enclosed or guarded to prevent accidental contact.
   • Barriers, partitions, or elevated placement may be used.
7. 110.31 – Electrical Installations in Buildings and Structures
   • Protect equipment from moisture, corrosive materials, or mechanical impact depending on the environment.

⚙️ Key Takeaways

• Always use listed and labeled equipment.
• Follow the manufacturer’s instructions — they are legally enforceable under the NEC.
• Maintain safe working clearances and proper mechanical workmanship.
• Inspectors and electricians must verify compliance with Article 110 on every installation.