Carrying a Powerful Message

摘要

During the recent 2017 National Electrical Code(NEC) first revision meetings in Hilton Head, S.C., a number of public inputs were submitted to introduce a new cabling system into Article 725 and Article 760. Article 725 covers Class 1,2 and 3 remote control, signaling and power-limited circuits, and Article 760 covers nonpower-limited and power-limited fire alarm circuits. The new cabling system being proposed for these two articles is to be called limited power (LP) cable, which is to be used for delivery of power and data through network cabling, such as power over Ethernet (PoE). I investigated the cabling system and the potential application for the system with regard to fire alarm systems, remote control, signaling and power-limited installations.