Copper Cabling Installation Considerations

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• Installation of cable must be compliant with local building regulations and fire codes
  • specific cable types must be used in some installation scenarios

Plenum Cable

A plenum space is a void in a building designed to carry heating, ventilation, and air conditioning (HVAC) systems.

• Plenum space is typically a false ceiling
  • though it could also be constructed as a raised floor
• space is used for communications wiring
  • makes installation simpler
• effective conduit for fire, as there is plenty of airflow and no fire breaks
• used for heating, so may have higher temperatures
  • regulations require use of fire-retardant plenum cable
    • must:
      • not emit large amounts of smoke when burned
      • be self-extinguishing
      • meet other fire safety standards
• General purpose (non-plenum) cabling uses PVC jackets and insulation
• Plenum-rated cable uses treated PVC or fluorinated ethylene polymer (FEP)
  • makes the cable less flexible
  • but the different materials have no effect on bandwidth
• Plenum-rated cable is marked CMP
  • under U.S. National Electrical Code (NEC)
• General-purpose cables are marked as:
  • CMG or MMG for PVC jackets
  • CM or MP for plenum-rated cables

Riser-Rated Cable

Riser cabling is cabling that passes between floors.

• conduit for riser cabling must be fire-stopped
  • fire cannot spread through
• must meet fire-safety standards
  • less strict than plenum-rated
  • can use plenum-rated for riser cabling, but not vice versa
    • both include rope/filament to support weight when installed vertically
• marked CMR under the NEC

Direct Burial

Outside plant (OSP) is cable run on the external walls of a building or between two buildings.

• makes the cable vulnerable to different types of weathering:
  • Aerial cable is typically strung between two poles or anchors
    • ultraviolet (UV) rays in sunlight plus exposure to more extreme and changing temperatures and damp conditions will degrade regular PVC
  • Conduit can provide more protection for buried cable runs
    • can still be exposed to extreme temperatures and damp conditions, however, so regular PVC cable should not be used
  • Direct burial cable is laid and then covered in earth or cement/concrete
• OSP cable types use special coatings to protect against UV and abrasion and are often gel filled to protect against temperature extremes and damp conditions
• Direct burial cable may also need to be armored to protect against chewing by rodents