What type of circuits is defined in Article 725?

Article 725 of the National Electrical Code (NEC) specifically addresses remote-control, signaling, and power-limited circuits. This category encompasses circuits designed for the control and signaling of equipment, which may include various applications such as alarms, control systems, and other communication mechanisms used in industrial and residential settings.

The inclusion of remote-control and signaling circuits in Article 725 is crucial because these types of circuits often operate at lower voltages and have unique installation requirements that differ from standard power circuits. This includes specified wire types, methods of installation, and the need to prevent interference with other electrical systems.

The focus of Article 725 ensures that these circuits are installed safely and effectively, meeting the necessary performance standards to operate reliably without causing hazards. It also differentiates the requirements for these circuits from those associated with higher voltage applications, ensuring the safety of both the installation workers and the end-users.

Other options pertain to different aspects of electrical installations. For example, critical operations power systems and instrumentation tray cables involve specific requirements for electrical systems that manage crucial functions or data transfer, while optical fiber cables deal with the transmission of light signals rather than electrical signaling. Each of these topics is relevant in its proper context but does not fall under the purview of Article