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PLENUM CABLE

What Is Plenum Cable?
Plenum cables are approved by Underwriters Laboratories for non-conduit applications located in environmental air spaces. This low cost alternative has replaced traditional conduit use in many commercial installations. Flexible plenum cables are safe, easy to install and provide a significant cost saving.  
Why Use Plenum Cable?
Commercial constructions often use suspended ceilings as return passages for environmental air. These "plenum" spaces have become convenient wiring locations for a variety of applications. However, use of these areas may pose a serious hazard in the event of a fire. Once the fire reaches the plenum space, few barriers exist to contain the smoke and flames.  Additionally, the plenum passage carries air at an increased velocity when the HVAC system is operational thereby moving this “returned” air at a greater velocity causing fire to spread more quickly. The National Fire Protection Association (NFPA) has recognized the potential for a hazard created by wire and cable in an environmental air space. Severe restrictions on cabling were included in the 1975 edition of the NEC. All following NEC editions set forth safety requirements for flammable insulations. The National Electric Code (NEC) states that all cabling not in conduit, installed in plenum spaces, shall be listed as having adequate fire-resistant and low smoke-producing characteristics.
 
CL2P:
NEC Article 725 covers remote-control, signaling and power-limited circuits that are not an integral part of a device or appliance. Type CL2P (class 2 plenum) cables are listed as being suitable for use in ducts, plenums and other space used for environmental air and shall also be listed as having adequate fire-resistant and low smoke-producing characteristics.
 
FPLP:
NEC Article 760 covers the installation of wiring and equipment of fire alarm systems including all circuits controlled and powered by the fire alarm system. Type FPLP (fire power limited plenum) cables are listed as being suitable for use in ducts, plenums and other space used for environmental air and shall also be listed as having adequate fire-resistant and low smoke-producing characteristics.
 
CMP &
MPP:
NEC Article 800 covers telephone, telegraph (except radio), outside wiring for fire alarm and burglar alarm, and similar central station systems, and telephone systems not connected to a central station system but using similar types of equipment, methods of installation and maintenance. Type CMP (communications plenum) and MPP (multi-purpose plenum) cables are listed as being suitable for use in ducts, plenums and other space used for environmental air and shall also be listed as having adequate fire-resistant and low smoke-producing characteristics.
 
 
When To Recommend Plenum Cable?
Plenum cables have become extremely popular for low voltage, environmental air space applications. Whether your installation includes security, fire, sound, HVAC or voice and data, plenum cables may be the most cost effective alternative.
 
New Construction
The cost of plenum cable may seem to be higher than standard non-plenum products. However, a cost savings of up to 50% can be achieved when specifying plenum cables in place of cable in conduit. Not only are labor and materials significantly reduced, but the building is assured of a secure cabling foundation for future expansion.
 
Existing Construction
Dramatic savings are possible with plenum cables in retrofit applications. Existing constructions often must be brought into compliance with current NEC or local codes. Conduit installation is often difficult, expensive and disruptive to the building occupants.
 
How To Identify Plenum Cable?
Classified vs. Listed Plenum Cables
Many electrical and electronic wiring systems require cables to be "listed" with an approved agency such as UL (Underwriters Laboratories). Cables used in specific environments such as plenum spaces must also be "classified" for the application. To receive a classification, the device or cable must pass a test for the application or installation type. In the case of plenum applications, all cables must pass the UL 910 Steiner tunnel test. CCI plenum cables cables are both listed with UL and classified by the NEC for use in plenum installations. Beware of imitations that are "plenum-listed" or "plenum approved". These cables may not meet current UL and NEC requirements. All listed and classified cables must be identified every 24 inches with printing on the jacket or an internal marker tape.
 
Example:
71902 18 AWG 2/C C(ETL) US (ETL CODE) TYPE CMP/CL3P/FPLP 75C -- TYPE CMP FT6
 
Overview of Plenum Cable

Plenum cables provide a quick, easy alternative to cables in conduit:

  • No conduit.
  • No pipe bending equipment needed.
  • No messy pulling compounds.
  • Fewer components are needed.
  • Less time and effort.