Many wires and cables are installed inside different types of buildings and are often deployed in riser and plenum areas. Due to the nature of these areas, wires and cables used in them need to meet certain specifications and will be denoted with riser and plenum ratings. Is there any differences in the use of these wires and cables?
Riser-Rated Cable
A riser is the vertical shaft, area, or series of rooms between two floors inside a building. These spaces allow primary utilities to be distributed vertically. Good examples of riser areas are elevator shafts and pipes from one floor to another. Riser wires and cables can be a building’s backbone that transmits data, audio and video signals.
Wires and cables with riser ratings are self-extinguishing to prevent flames from travelling up the wire and jumping floors in a building. However, riser ratings are not as strict as plenum ratings.
Riser Wires and Cables Offered by DigiKey
Fiber Optic Cables | Electronic Components Distributor DigiKey
Multiple Conductor Cables | Electronic Components Distributor DigiKey
Coaxial Cables (RF) | Electronic Components Distributor DigiKey
Modular/Ethernet Cables (RJ45, RJ11) | Electronic Components Distributor DigiKey
Pluggable Cables | Electronic Components Distributor DigiKey
Plenum-Rated Cable
A plenum is the pathway or space used to circulate air as part of a building’s HVAC system. It is usually above a ceiling or below a floor that can serve as a receiving chamber for air that has been heated or cooled to be distributed to inhabited areas. As the plenum spaces contain few fire barriers and forced-air circulation, the wires and cables deployed in them need a higher fire resistance than those used in riser spaces.
Wires and cables with plenum ratings are made with fire-retardant plastic jackets such as PVC or FEP. Even if a fire were to ignite, fewer toxic fumes are emitted as the jacket melts.
Plenum Wires and Cables Offered by DigiKey
Fiber Optic Cables | Electronic Components Distributor DigiKey
Multiple Conductor Cables | Electronic Components Distributor DigiKey
Coaxial Cables (RF) | Electronic Components Distributor DigiKey
Coaxial Cables (RF) | Electronic Components Distributor DigiKey
Modular/Ethernet Cables (RJ45, RJ11) | Electronic Components Distributor DigiKey
Pluggable Cables | Electronic Components Distributor DigiKey
Video Cables (DVI, HDMI) | Electronic Components Distributor DigiKey
Plenum Rated Spiral Wrap and Expandable Sleeving
Spiral Wrap, Expandable Sleeving | Electronic Components Distributor DigiKey
Here are some notes for your consideration between riser and plenum rated wires and cables.
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A plenum rated wire or cable can be used in a riser space, but a wire or cable with a riser rating generally cannot be used in a plenum space.
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In the event of a fire, using the wrong wire or cable type may increase the damage and loss of life. Depending on the laws in your area it may also leave you open to liability or prosecution depending on the circumstances. Using the correct cable type can not only help to ensure safety but also reduce building damage and avoid liability and other legal issues.
Please review the datasheets to ensure the chosen wire or cable meets all international, federal, state, and local laws that are applicable to installation of these products in your area.