The Basics of Conductor Sizing — Part 2

The Basics of Conductor Sizing — Part 2

You don’t size feeder conductors the same way you size branch circuit conductors.

As we saw in Part 1, the correct sizing of conductors is more complicated than it appears. One of the reasons is the way temperature affects the resistance of a conductor. Higher temperatures mean less current-carrying capacity for a given size conductor. A conductor may have sufficient ampacity at one temperature, but at a higher temperature it just can’t take the heat.

We use ampacity tables to select the correct ampacity, but the ampacity tables are based on 86°F. What if y

Register to view the full article

Register on EC&M and gain access to premium content, including this article and much more.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.