RED ALERT® RedWiring in Plenums, Ducts or Other Spaces Used for Environmental Air-Handling Purposes per NEC 300.22(B), 300.22(C) & 760.71(D) Power-Limited and Non-Power Limited fire alarm circuits, including smoke detectors, bells, horns, fire alarm control panel equipment, and initiation and signaling devices. Class 1, Class 2, and Class 3 remote control, signaling, and power-limited circuits. Power, lighting, control, and signal circuits. Fished or embedded in plaster. Concealed or exposed installations. Places of Assembly per NEC 518.4 and Theaters per NEC 520.5. As aerial cable on a messenger. Installation in cable tray and approved raceways. Under raised floors for information technology equipment conductors and cables per NEC 645.5(D) & 645.5(D)(2).