In last month's “Code Basics” article, starting on page 56 of the September issue, we spent most of our time discussing Class 1 circuits. Now, it's time to switch gears and focus on Class 2 and 3.

Circuits that fall under the requirements of Art. 725 are remote-control, signaling, and power-limited circuits that aren’t an integral part of a device or appliance. Article 725 includes circuits for ...