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 240.4 in the National Electrical Code (NEC) is a reference table used to determine the minimum size of conductors for branch circuits and feeders based on the overcurrent protection device (OCPD) rating.

Here’s a step-by-step guide on how to use Table 240.4:

  1. Determine the rating of the OCPD in amperes for the circuit you are designing. This can be found on the circuit breaker or fuse that will be used to protect the circuit.

  2. Determine the material and size of the conductor you plan to use. This information can be found on the conductor manufacturer’s specification sheet or in NEC Table 310.16.

  3. Locate the column in Table 240.4 that corresponds to the OCPD rating. The OCPD rating is listed in the left-hand column, while the conductor size is listed in the top row.

  4. Find the intersection of the OCPD rating column and conductor size row to determine the minimum size conductor required for the circuit.

It’s important to note that Table 240.4 provides minimum conductor size requirements, and larger conductors may be required based on other factors such as voltage drop or ambient temperature. Always consult the NEC and any local codes and regulations for specific requirements in your area.

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