The National Electrical Code (NEC) Article 725 provides requirements for the installation and use of remote-control, signaling, and power-limited circuits. This article covers wiring methods, grounding, marking, and other related requirements for these types of circuits.
In general, remote-control circuits are those that operate devices or systems from a remote location, such as a control room or a switchboard. Signaling circuits are used to transmit signals, messages, or alarms, and power-limited circuits are low-voltage circuits that are used to power equipment such as thermostats or doorbells.
NEC Article 725 includes specifications for the installation and use of these types of circuits in various locations and applications, including commercial, residential, and industrial settings. Some of the key requirements include:
Wiring methods: The article provides guidance on the types of wiring methods that can be used for remote-control, signaling, and power-limited circuits, including cable, conduit, and raceways.
Grounding: The article includes requirements for grounding and bonding of remote-control, signaling, and power-limited circuits, as well as guidelines for the use of ground-fault protection devices.
Marking and labeling: The article requires that remote-control, signaling, and power-limited circuits be clearly marked and labeled to indicate their function and purpose.
Overall, NEC Article 725 is intended to help ensure the safe installation and use of remote-control, signaling, and power-limited circuits, and to minimize the risk of electrical hazards and accidents.