Terminology » Networking Basics » LSZH vs Plenum vs Riser Cables: Key Differences Explained

LSZH vs Plenum vs Riser Cables: Key Differences Explained

cable lszh plenum riser networking

This article breaks down the differences between LSZH, Plenum, and Riser cables, outlining their unique characteristics and applications. We’ll explore what sets them apart and help you choose the right cable for your specific needs.

What is LSZH Cable?

  • LSZH stands for Low Smoke Zero Halogen.
  • These cables are designed with a jacket material that is free from halogenic materials like chlorine and fluorine. This is crucial because these chemicals release toxic substances when burned.
  • LSZH cables are primarily used in Europe.

LSZH Cable

Figure 1 depicts an LSZH cable.

What is Plenum Cable?

  • Plenum (CMP) rated cable complies with NFPA-262 and UL-910 standards.
  • The term “plenum” refers to airspace used for air circulation by HVAC systems, such as the space above a drop ceiling or under a raised floor.
  • Plenum cables are designed with jackets made of materials that produce low amounts of smoke and resist the spread of flames.
  • A common jacket material is Fluorinated Ethylenepropylene, a more flexible version of Teflon® (also known as PTFE).

Plenum cable

Figure 2 depicts a Plenum cable.

What is Riser Cable?

  • Riser (CMR) rated cable complies with UL-1666 standards.
  • It is used in commercial buildings. “Riser” refers to the vertical space used by telecom infrastructure to connect different floors.
  • OFNR (Optical Fiber Non-conductive Riser) cables lack conductive metal structures and are approved for riser applications.
  • Most optical fiber cables are made of non-conductive materials like glass and plastic.

Riser cable

Figure 3 depicts a riser cable.

LSZH cable vs Plenum cable vs Riser cable

Difference between LSZH, Plenum, and Riser Cables

The following table compares normal PVC, LSZH, Plenum, and Riser cables based on key features:

FeaturesNormal PVC cableLSZH cablePlenum cableRiser cable
FlammabilityHigh, burns rapidly, non-self extinguishMedium, may self extinguish when flame removedLow, burns, but will self extinguish when flame removedLow, burns, but will self extinguish when flame removed
Toxicity/ Corrosive LevelHigh, when burned gives toxic and corrosive gassesLow, no corrosive gasses, but gives off carbon monoxide when burnedHigh, when burned gives off toxic and corrosive gasesHigh, when burned gives off toxic and corrosive gases
Typical applicationMost computer cabling found in offices and homesCabling found in enclosed areas such as ships, submarines, high computer rooms, network centers, aircrafts etc.Cabling found inside walls, ceilings and air plenums of office or private buildings.Same as Plenum cable