According to the NEC, what is a circuit that energizes signaling equipment called?

A circuit that energizes signaling equipment is referred to as a signaling circuit. This type of circuit is specifically designed to carry current to devices that provide notifications or alerts, such as bells, alarms, or lights used for signaling purposes. Signaling circuits are distinct in that they often operate at lower voltages and are meant to convey information rather than provide standard power for devices. Being categorized under the National Electrical Code (NEC), they are subject to specific installation rules and safety standards to ensure that signaling systems function reliably and safely.

While other circuits like control circuits, power circuits, or alarm circuits may also involve elements of signaling, they do not specifically define the function of energizing signaling equipment in the context provided. Control circuits generally manage the operation of devices rather than directly signaling. Power circuits provide electrical energy for general use across devices and systems but typically do not relate to signaling. Alarm circuits may be part of signaling systems but may encompass broader functionalities beyond just signaling alone. Thus, "signaling circuit" is the most accurate term for a circuit specifically intended for this purpose.