The NEC is arranged in a particular way, and one feature of that is the first four chapters apply generally to all installations, meaning in the sense “where applicable.” For example, Art. 210 applies to branch circuits not over 1,000V. It does not apply to services. Article 230 applies to services, but it does not apply to branch circuits. Article 430 applies to motors, so you don’t need it if you are installing lights instead of motors.
Chapters 5, 6, and 7 apply to “special” occupancies, equipment, and conditions. Chapter 8 applies to communications systems, and Chapter 9 consists of tables. These Articles don’t provide generally applicable requirements.
Chapter 1 consists of two Articles:
- Article 100. This provides definitions of terms used elsewhere in the Code.
- Article 110. This provides the general requirements for all electrical installations.
The scope of Art. 110 is a little dense for a single sentence, so let’s break it down. It covers the general requirements for this list:
- Examination
- Approval
- Installation
- Use
- Access to
- Spaces about
Pertaining to:
- Electrical conductors
- Electrical equipment
- Enclosures intended for personnel entry
- Tunnel installations
Looking at the scope this way can help you more easily understand it. But an even simpler way of looking at the scope of Art. 110 is it applies to any conductors or equipment you are installing, which leads us into the next concept: Conductors and equipment that are required or permitted by the NEC are acceptable only if approved [Art. 110.2]. And you can find the definition of “approved” in the other Chapter 1 Article [100].
