National electrical code article 760 – National Electrical Code (NEC) Article 760 establishes comprehensive guidelines for the design, installation, and maintenance of fire alarm systems. This article provides a detailed framework to ensure the reliability and effectiveness of fire alarm systems in safeguarding lives and property.
NEC Article 760 covers a wide range of topics, including the types of conductors and cables permitted, circuit design requirements, power sources, signaling appliances, smoke detectors, heat detectors, manual fire alarm boxes, fire alarm control units, and inspection and maintenance procedures.
By adhering to these guidelines, electrical professionals can ensure that fire alarm systems are installed and maintained to the highest standards of safety and reliability.
Scope and Application
NEC Article 760 provides the requirements for the installation, maintenance, and use of fire alarm systems in commercial and industrial buildings. This article covers all aspects of fire alarm systems, from the design and installation of the system to the inspection and maintenance of the system.
Some examples of installations covered by this article include:
- Fire alarm systems in office buildings
- Fire alarm systems in schools
- Fire alarm systems in hospitals
- Fire alarm systems in industrial facilities
Definitions
The following terms are used in NEC Article 760:
| Term | Definition |
|---|---|
| Fire alarm system | A system that detects and alerts people to the presence of fire. |
| Fire alarm control unit | The central component of a fire alarm system that receives and processes signals from fire alarm devices and initiates the appropriate response. |
| Fire alarm device | A device that detects the presence of fire and sends a signal to the fire alarm control unit. |
| Signaling appliance | A device that provides an audible or visual signal to alert people to the presence of fire. |
Conductors and Cables
The conductors and cables used in fire alarm systems must be listed for use in fire alarm systems. The conductors must be insulated with a fire-resistant material and must be installed in a manner that protects them from damage.
The following types of conductors and cables are permitted for use in fire alarm systems:
- Type FPL
- Type FPLP
- Type FPLR
- Type FPLV
Circuit Design
Fire alarm systems must be designed in accordance with the requirements of NEC Article 760. The circuits must be designed to provide reliable operation and to minimize the risk of false alarms.
The following are some of the circuit design requirements for fire alarm systems:
- The circuits must be supervised to ensure that they are functioning properly.
- The circuits must be designed to minimize the risk of cross-talk between circuits.
- The circuits must be designed to provide the required level of power to the fire alarm devices.
Power Sources
Fire alarm systems must be powered by a reliable source of power. The power source must be capable of providing the required level of power to the fire alarm system for at least 24 hours in the event of a power outage.
The following types of power sources are permitted for use in fire alarm systems:
- Commercial power
- Batteries
- Generators
Signaling Appliances
Fire alarm systems must be equipped with signaling appliances that are capable of alerting people to the presence of fire. The signaling appliances must be audible and visible and must be installed in a manner that ensures that they can be heard and seen by all occupants of the building.
The following types of signaling appliances are permitted for use in fire alarm systems:
- Bells
- Horns
- Strobes
- Speakers
Smoke Detectors
Smoke detectors are used to detect the presence of smoke. Smoke detectors must be installed in accordance with the requirements of NEC Article 760. The smoke detectors must be located in a manner that ensures that they will detect smoke from any fire in the building.
The following types of smoke detectors are permitted for use in fire alarm systems:
- Ionization smoke detectors
- Photoelectric smoke detectors
- Combination smoke detectors
Heat Detectors
Heat detectors are used to detect the presence of heat. Heat detectors must be installed in accordance with the requirements of NEC Article 760. The heat detectors must be located in a manner that ensures that they will detect heat from any fire in the building.
The following types of heat detectors are permitted for use in fire alarm systems:
- Fixed-temperature heat detectors
- Rate-of-rise heat detectors
Manual Fire Alarm Boxes
Manual fire alarm boxes are used to manually activate the fire alarm system. Manual fire alarm boxes must be installed in accordance with the requirements of NEC Article 760. The manual fire alarm boxes must be located in a manner that ensures that they are accessible to all occupants of the building.
Fire Alarm Control Units
Fire alarm control units are the central component of a fire alarm system. Fire alarm control units must be installed in accordance with the requirements of NEC Article 760. The fire alarm control units must be located in a manner that ensures that they are accessible to authorized personnel.
Inspection and Maintenance: National Electrical Code Article 760
Fire alarm systems must be inspected and maintained in accordance with the requirements of NEC Article 760. The inspections and maintenance must be performed by qualified personnel.
The following are some of the inspection and maintenance requirements for fire alarm systems:
- The fire alarm system must be inspected at least once a year.
- The fire alarm system must be tested at least once a month.
- The fire alarm system must be serviced at least once every six months.
FAQ Explained
What is the purpose of NEC Article 760?
NEC Article 760 provides comprehensive guidelines for the design, installation, and maintenance of fire alarm systems to ensure their reliability and effectiveness in protecting lives and property.
What types of installations are covered by NEC Article 760?
NEC Article 760 covers fire alarm systems installed in a wide range of occupancies, including residential, commercial, industrial, and institutional buildings.
What are the key terms used in NEC Article 760?
NEC Article 760 defines key terms such as “fire alarm system,” “initiating device,” “notification appliance,” and “supervisory signal.” A comprehensive table summarizing these definitions is provided in the article.
What are the requirements for installing and supporting conductors in fire alarm systems?
Conductors used in fire alarm systems must be listed for the purpose and installed in accordance with NEC Article 760. The article provides specific requirements for the installation and support of conductors, including the use of approved raceways, cables, and fittings.
What are the circuit design requirements for fire alarm systems?
NEC Article 760 Artikels the circuit design requirements for fire alarm systems, including the use of supervised circuits, the maximum number of devices permitted on a circuit, and the requirements for circuit supervision.
