ABSTRACT

Coffee Break Training: Power-Limited and Nonpower-Limited Circuits   [open pdf - 98KB]

"While NFPA [National Fire Protection Association] 72, 'National Fire Alarm Code' establishes standards for the design, installation and maintenance of fire detection and alarm systems, it is NFPA 70, 'National Electrical Code' (NEC), that prescribes the rules for point-to-point wiring in a fire protection signaling system. Article 760 provides detailed requirements for wire types permitted in fire alarm systems, and Article 770 provides rules for optical fiber cables. NEC Article 760 applies to all the wiring between the 'load side of the overcurrent protection device (circuit breaker) or the power-limited supply (battery) and all connected equipment.' There are two types of fire alarm system circuits: power-limited and nonpower-limited. The purpose for identifying the different circuits is to specify the appropriately rated wire, as well as provide protection so high voltage conductors are not inadvertently connected to low voltage ones. The result could be an accidental electrocution or destruction of the fire alarm system."

Report Number:
Coffee Break Training - Fire Protection Series No. 2007-12
Publisher:
Date:
2007-03-20
Series:
Copyright:
Public Domain
Retrieved From:
United States Fire Administration: http://www.usfa.fema.gov/
Format:
pdf
Media Type:
application/pdf
URL:
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