EC&M Tech Talk — Conduits: Where’s the Info – What Do I Use Where – Size Them Correctly

This EC&M Tech Talk begins in the Table of Contents of the 2026 NEC. Locating the article number is the first step in working with conduits and tubing. Designed to protect and support conductors, the definitions of these circular raceways are covered in Art. 100 Definitions. Understanding the different types and construction of conduit and tubing is key to applying these raceways in the field.

Conveniently, each of the articles is laid out in the same manner. For example, section xxx.10 for that article will always be uses permitted and section xxx.12 lists where the conduit use in not permitted. Just knowing this information helps to ensure the correct conduit is selected for a particular application. If not sure of where to support a specific conduit or tubing, see xxx.30 in the appropriate article. It will be support requirements.

Finally, the two options provided for sizing circular raceways is covered with examples of each. If all conductors are the same size, then Informative Annex C is the simple answer to determine the conduit size. For conductors of different sizes an example is walked through using Chapter 9 Tables 5 and then 4.

Conduits and tubing are found in the vast majority of all installations and serve a very important purpose of protecting conductors. Using the wrong type of raceway is of course a code violation. Not properly sizing these conduits and tubing can result in conductor damage during installation and possible overheating during operation. Use this EC&M Tech Talk to learn and review as needed.