Course Content
Article 200 – Use and Identifications of Grounded Conductors
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Article 210 Branch Circuits
Article 210 of the National Electrical Code (NEC) covers the requirements for branch circuits, which are the circuits that supply power to the outlets, lighting fixtures, and other loads in a building. In this lesson, we will discuss the key requirements of Article 210.
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Article 215 Feeders
Article 215 of the National Electrical Code (NEC) covers the requirements for feeders, which are the circuits that supply power from the service equipment to the branch circuits in a building. In this lesson, we will discuss the key requirements of Article 215.
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Article 230 Services
In summary, Article 230 provides specific requirements for the installation of service conductors and equipment to ensure safe and reliable delivery of electrical power to buildings and structures.
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Article 242: Overvoltage Protection
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NEC Chapter 2 Wiring and Protection
About Lesson

Table 240.6 is used in the National Electrical Code (NEC) to determine the minimum size of conductors and maximum overcurrent protection for feeders and branch circuits based on the conductor ampacity and the rating of the overcurrent protective device (OCPD).

Here are the steps to use Table 240.6:

  1. Determine the ampacity of the conductor based on the application and the wire size using NEC Table 310.15(B)(16) or Table 310.15(B)(17) if it is a copper conductor or Table 310.15(B)(16) if it is an aluminum conductor.

  2. Determine the rating of the overcurrent protective device (OCPD) based on the ampacity of the conductor using NEC 240.4. This will give you the maximum rating of the OCPD that can be used to protect the conductor.

  3. Look for the conductor size and type in the left-hand column of Table 240.6.

  4. Find the corresponding OCPD rating in the top row of the table.

  5. Where the column and row intersect is the minimum size conductor required for the corresponding OCPD rating.

It is important to note that Table 240.6 is based on a 75-degree Celsius (167-degree Fahrenheit) ampacity rating for conductors. If the conductors have a higher temperature rating, adjustments to the ampacity may be necessary.

Also, be sure to follow all applicable codes and regulations when designing and installing electrical systems to ensure safety and compliance.

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