In the context of networking and cable management plenum rated cable is defined as cable that is safe to install in air ducts plenums and other spaces used for environmental air handling. The main reason for this is that the insulation on plenum cable is made of a material that does not release toxins when it burns unlike the PVC insulation found on non-plenum cable.
The National Electrical Code (NEC) states that in order to be considered plenum cable the insulation must have a Flame Spread Index of 75 or less and a Smoke Developed Index of 50 or less.
Beyond the insulation plenum cable must also have a jacket that is made of a flame retardant material. This is to further reduce the spread of fire should the cable catch fire.
The use of plenum cable is not required in all applications but it is always recommended in any space where there is a risk of fire. This includes places like office buildings schools hospitals and any other commercial or industrial buildings.
If you are unsure whether or not your application requires plenum cable it is always best to consult with a licensed electrician or cable installer.
References:
https://www.cablinginstall.com/articles/2003/03/what-is-plenum-cable-and-do-i-need-to-use-it
https://www.electricalcontractor.net/article/what-plenum-cable/
https://www.necasagroup.com/what-is-plenum-cable-and-why-is-it-important/
What is plenum rated cable?
Plenum rated cable is a type of cable that is designed to be used in plenum spaces.
Plenum spaces are areas where air is circulated such as in HVAC systems.
What are the benefits of using plenum rated cable?
Plenum rated cable is more fire resistant than non-plenum rated cable making it a safer option for use in areas where there is a risk of fire.
Are there any disadvantages to using plenum rated cable?
Plenum rated cable is more expensive than non-plenum rated cable.
Where can plenum rated cable be used?
Plenum rated cable can be used in any area where air is circulated such as in HVAC systems but is most commonly used in office buildings.
How is plenum rated cable different from non-plenum rated cable?
Plenum rated cable is more fire resistant than non-plenum rated cable.
Why is plenum rated cable more fire resistant?
Plenum rated cable is made of materials that are designed to release less toxic smoke when they burn making them safer to use in areas where there is a risk of fire.
Is plenum rated cable more expensive than non-plenum rated cable?
Yes plenum rated cable is more expensive than non-plenum rated cable.
How much more expensive is plenum rated cable?
Plenum rated cable is typically 20-30% more expensive than non-plenum rated cable.
Why is plenum rated cable more expensive?
Plenum rated cable is more expensive because it is made of more expensive materials and because it undergoes more rigorous testing than non-plenum rated cable.
What does plenum rated cable have to undergo more rigorous testing?
Plenum rated cable has to undergo more rigorous testing because it is designed for use in areas where there is a risk of fire.
How often should plenum rated cable be replaced?
Plenum rated cable should be replaced every 10-15 years.
Why should plenum rated cable be replaced every 10-15 years?
Plenum rated cable should be replaced every 10-15 years because the materials it is made of can degrade over time making it less fire resistant.
What happens if plenum rated cable is not replaced every 10-15 years?
If plenum rated cable is not replaced every 10-15 years it may not provide adequate fire protection.
What are the consequences of plenum rated cable not providing adequate fire protection?
If plenum rated cable does not provide adequate fire protection it could lead to a fire in the building.
How can I find out if my building has plenum rated cable?
You can ask your building manager or contact the cable company that installed the cable in your building.
