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Optical Fiber, Nonconductive, Riser
Optical fiber, nonconductive, riser (OFNR) is a type of optical fiber cable. As designated by the National Fire Protection Association (NFPA), this name is used for interior fiber-optic cables which contain no electrically conductive components, and which are certified for use in riser applications; they are engineered to prevent the spread of fire from floor to floor in a building. Typically they are tested for compliance with ANSI/UL 1666–1997, ''Standard Test for Flame Propagation Height of Electrical and Optical-Fiber Cable Installed Vertically in Shafts''. NFPA NEC 2005 Art 770.51(B) FPN. They are distinct from optical fiber, nonconductive, plenum cable (OFNP), and general-purpose optical cable. Related abbreviations Underwriters Laboratories The UL enterprise is a global safety science company headquartered in Northbrook, Illinois, composed of three organizations, UL Research Institutes, UL Standards & Engagement and UL Solutions. Established in 1894, the UL enterp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Fiber Cable
A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an electrical cable, but containing one or more optical fibers that are used to carry light. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable is used. Different types of cable are used for different applications, for example, long distance telecommunication, or providing a high-speed data connection between different parts of a building. Design Optical fiber consists of a core and a cladding layer, selected for total internal reflection due to the difference in the refractive index between the two. In practical fibers, the cladding is usually coated with a layer of acrylate polymer or polyimide. This coating protects the fiber from damage but does not contribute to its optical waveguide properties. Individual coated fibers (or fibers formed into ribbons or bundles) then have a tough ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Fire Protection Association
The National Fire Protection Association (NFPA) is an international nonprofit organization devoted to eliminating death, injury, property and economic loss due to fire, electrical and related hazards. As of 2018, the NFPA claims to have 50,000 members and 9,000 volunteers working with the organization through its 250 technical committees. History In 1895, a Committee on Automatic Sprinkler Protection was formed in Massachusetts by men affiliated with several fire insurance companies and a pipe manufacturer to develop a uniform standard for the design and installation of fire sprinkler systems. At the time, there were nine such standards in effect within of Boston, Massachusetts, and such diversity was causing great difficulties for plumbers working in the New England region. The next year, the committee published its initial report on a uniform standard, and went on to form the NFPA in late 1896. The committee's initial report evolved into NFPA 13, ''Standard for the Installat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Conduction
Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows electric current. Resistivity is commonly represented by the Greek letter (rho). The SI unit of electrical resistivity is the ohm-meter (Ω⋅m). For example, if a solid cube of material has sheet contacts on two opposite faces, and the resistance between these contacts is , then the resistivity of the material is . Electrical conductivity or specific conductance is the reciprocal of electrical resistivity. It represents a material's ability to conduct electric current. It is commonly signified by the Greek letter ( sigma), but (kappa) (especially in electrical engineering) and (gamma) are sometimes used. The SI unit of electrical conductivity is siemens per metre (S/m). Resistivity and conductivity are intensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riser Cable
__NOTOC__ Plenum cable is electrical cable that is laid in the plenum spaces of buildings. In the United States, plastics used in the construction of plenum cable are regulated under the National Fire Protection Association standard NFPA 90A: Standard for the Installation of Air Conditioning and Ventilating Systems. All materials intended for use on wire and cables to be placed in plenum spaces are designed to meet rigorous fire safety test standards in accordance with NFPA 262 and outlined in NFPA 90A. Plenum cable is jacketed with a fire-retardant plastic jacket of either a low-smoke polyvinyl chloride (PVC) or a fluorinated ethylene polymer ( FEP). Polyolefin formulations, specifically based on polyethylene compounding had been developed by at least two companies in the early to mid-1990s; however, these were never commercialized, and development efforts continue in these yet-untapped product potentials. Development efforts on a non-halogen plenum compound were announced in 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engineer
Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limitations imposed by practicality, regulation, safety and cost. "Science is knowledge based on our observed facts and tested truths arranged in an orderly system that can be validated and communicated to other people. Engineering is the creative application of scientific principles used to plan, build, direct, guide, manage, or work on systems to maintain and improve our daily lives." The word ''engineer'' (Latin ) is derived from the Latin words ("to contrive, devise") and ("cleverness"). The foundational qualifications of an engineer typically include a four-year bachelor's degree in an engineering discipline, or in some jurisdictions, a master's degree in an engineering discipline plus four to six years of peer-reviewed professiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire
Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products. At a certain point in the combustion reaction, called the ignition point, flames are produced. The ''flame'' is the visible portion of the fire. Flames consist primarily of carbon dioxide, water vapor, oxygen and nitrogen. If hot enough, the gases may become ionized to produce Plasma (physics), plasma. Depending on the substances alight, and any impurities outside, the color of the flame and the fire's Intensity (heat transfer), intensity will be different. Fire in its most common form can result in conflagration, which has the potential to cause physical damage through burning. Fire is an important process that affects ecological systems around the globe. The positive effects of fire include stimulating growth and maintaining various ecological systems. Its negative effects include hazard to life and pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floor
A floor is the bottom surface of a room or vehicle. Floors vary from simple dirt in a cave to many layered surfaces made with modern technology. Floors may be stone, wood, bamboo, metal or any other material that can support the expected load. The levels of a building are often referred to as floors, although a more proper term is storey. Floors typically consist of a subfloor for support and a floor covering used to give a good walking surface. In modern buildings the subfloor often has electrical wiring, plumbing, and other services built in. As floors must meet many needs, some essential to safety, floors are built to strict building codes in some regions. Special floor structures Where a special floor structure like a floating floor is laid upon another floor, both may be called subfloors. Special floor structures are used for a number of purposes: * Balcony, a platform projecting from a wall * Floating floor, normally for noise or vibration reduction * Glass floor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Building
A building, or edifice, is an enclosed structure with a roof and walls standing more or less permanently in one place, such as a house or factory (although there's also portable buildings). Buildings come in a variety of sizes, shapes, and functions, and have been adapted throughout history for a wide number of factors, from building materials available, to weather conditions, land prices, ground conditions, specific uses, prestige, and aesthetic reasons. To better understand the term ''building'' compare the list of nonbuilding structures. Buildings serve several societal needs – primarily as shelter from weather, security, living space, privacy, to store belongings, and to comfortably live and work. A building as a shelter represents a physical division of the human habitat (a place of comfort and safety) and the ''outside'' (a place that at times may be harsh and harmful). Ever since the first cave paintings, buildings have also become objects or canvasses of much artist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plenum Cable
__NOTOC__ Plenum cable is electrical cable that is laid in the plenum spaces of buildings. In the United States, plastics used in the construction of plenum cable are regulated under the National Fire Protection Association standard NFPA 90A: Standard for the Installation of Air Conditioning and Ventilating Systems. All materials intended for use on wire and cables to be placed in plenum spaces are designed to meet rigorous fire safety test standards in accordance with NFPA 262 and outlined in NFPA 90A. Plenum cable is jacketed with a fire-retardant plastic jacket of either a low-smoke polyvinyl chloride (PVC) or a fluorinated ethylene polymer ( FEP). Polyolefin formulations, specifically based on polyethylene compounding had been developed by at least two companies in the early to mid-1990s; however, these were never commercialized, and development efforts continue in these yet-untapped product potentials. Development efforts on a non-halogen plenum compound were announced in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwriters Laboratories
The UL enterprise is a global safety science company headquartered in Northbrook, Illinois, composed of three organizations, UL Research Institutes, UL Standards & Engagement and UL Solutions. Established in 1894, the UL enterprise was founded as the Underwriters' Electrical Bureau (a bureau of the National Board of Fire Underwriters), and was known throughout the 20th century as Underwriters Laboratories. On January 1, 2012, Underwriters Laboratories became the parent company of a for-profit company in the U.S named UL LLC, a limited liability corporation, which took over the product testing and certification business. On June 26, 2022, the companies rebranded into three distinct organizations that make up the UL enterprise. UL Solutions partners with customers and stakeholders in more than 100 countries to help solve safety, security and sustainability challenges and is also responsible for managing and issuing the highly respected portfolio of UL Marks. The company is one of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
