How many first level subdivisions exist in section 250.122 – Section 250.122, a crucial regulation, establishes clear guidelines for various aspects. This article delves into the intricacies of this section, specifically addressing the number of first-level subdivisions it encompasses. By exploring the definition and methods for determining these subdivisions, we gain valuable insights into the structure and organization of this essential standard.
1. Introduction: How Many First Level Subdivisions Exist In Section 250.122
Section 250.122 of the National Electrical Code (NEC) provides guidelines for the installation of electrical equipment in hazardous (classified) locations. It defines “first level subdivisions” as the primary divisions within a classified location, such as Class I, Division 1 or Class II, Division 2.
2. Methods for Determining the Number of First Level Subdivisions
To determine the number of first level subdivisions in section 250.122, follow these steps:
- Identify the applicable article in section 250.122 based on the type of hazardous location.
- Count the number of subheadings that start with “Class” or “Division”.
- Subtract one from the total count, as the first subheading typically defines the general requirements for the classified location.
For example, in Article 501, “Class I Locations,” there are three subheadings: Class I, Division 1; Class I, Division 2; and Class I, Zones 0, 1, and 2. Subtracting one from the total count of three gives us a total of two first level subdivisions in Article 501.
3. Examples of First Level Subdivisions
The following table lists the different types of first level subdivisions that exist in section 250.122:
| Class | Division | Zone |
|---|---|---|
| Class I | Division 1 | Zone 0 |
| Class I | Division 2 | Zone 1 |
| Class II | Division 1 | Zone 2 |
| Class II | Division 2 | None |
| Class III | Division 1 | None |
| Class III | Division 2 | None |
4. Comparison to Other Standards
The number of first level subdivisions in section 250.122 is similar to other standards for hazardous locations, such as the International Electrotechnical Commission (IEC) 60079 series. However, there are some minor differences in the way that the subdivisions are defined and counted.
For example, the IEC 60079 series defines “zones” as the first level subdivisions within a hazardous location. Zones are similar to divisions, but they are based on the probability of the presence of a flammable atmosphere rather than the type of hazardous material.
5. Implications of the Number of First Level Subdivisions
The number of first level subdivisions in section 250.122 has several implications for the organization and implementation of the standard.
- It determines the number of different types of hazardous locations that are recognized by the NEC.
- It affects the way that electrical equipment is selected and installed in hazardous locations.
- It provides a framework for enforcing the requirements of the NEC in hazardous locations.
Helpful Answers
What is the significance of first-level subdivisions in Section 250.122?
First-level subdivisions provide a structured framework for organizing and classifying the content within Section 250.122, making it easier to locate specific information and understand the overall structure of the regulation.
How are first-level subdivisions defined in Section 250.122?
The Artikel defines first-level subdivisions as the primary sections or divisions within Section 250.122 that serve as broad categories for organizing the content.
