CLASS 1, CLASS 2, AND CLASS 3 REMOTE-

CONTROL, SIGNALING, AND POWER-LIMITED CIRCUITS A. General 725-1. Scope. This article covers remote-control, signaling, and powerlimited circuits that are not an integral part of a device or appliance. (FPN): The circuits described herein are characterized by usage and electrical power limitations that differentiate them from electric light and power circuits and, therefore, alternative requirements to those of Chapters 1 through 4 are given with regard to minimum wire sizes, derating factors, overcurrent protection, insulation requirements, and wiring methods and materials. 725-2. Locations and Other Articles. Circuits and equipment shall comply with (a), (b), (c), (d), and (e) below. (a) Spread of Fire or Products of Combustion. Section 300-21. (b) Ducts, Plenums, and Other Air-Handling Spaces. Section 300-22, where installed in ducts or plenums or other space used for environmental air. Exception to (b): As permitted in Section 725-53(a). (c) Hazardous (Classified) Locations. Articles 500 through 516, and