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When Should Plenum Cable be Used? Article 800 of the National Electrical Code (NEC) states that plenum cable should ALWAYS be used in plenum airspaces and air ducts to slow down the spread of flames and reduce smoke and toxic fumes from circulating throughout the building.
Is plenum cable required?
Plenum cable is mandated to be installed in any “air handling” space. For example, most large office buildings use the ceiling to return air to the AC unit. This qualifies this ceiling as a plenum ceiling, and all the cables that go through that ceiling must be plenum rated.
Is plenum cable required in residential?
If there is no sheet metal duct; just the open ceiling or wall space, then you are required by law to use Plenum Rated cable. The lack of wall or ceiling return air grates is usually a sure sign that you require Plenum Rated Cable.
What is considered a plenum space?
In building construction Plenum is a separate space provided for air circulation for heating, ventilation, and air-conditioning. It is commonly found in the space between the structural ceiling and a drop-down ceiling or under a raised floor.
Is an open ceiling considered a plenum?
Plenum spaces are the open spaces above the ceiling or below the floor that are used for air circulation. Technically, any ductwork is considered a plenum space too. Plenum spaces provide two problems if there is ever a fire.
Why would you use plenum cable?
Plenum rated cable has a special insulation that has smoke and low flame characteristics. It is mandated to be installed in any “air handling” space. For instance, most large office buildings use the ceiling to return air to the AC unit. At that point, the use of plenum cables ensures safety.
Can I run Ethernet through cold air return?
Yes, it is within code to run a low voltage wire inside an air return (aka plenum) in the US.
Can I use riser cable outside?
Riser and plenum jackets are mostly PVC, and as such will allow moisture vapor to enter and escape the cable as the temperature changes. This is normally not an issue inside a climate-controlled environment and is a phenomenon that goes unnoticed. Running riser or plenum cable outside, though, is a very bad idea.
Can plenum cable be used outside?
Plenum cable is rated for the “plenum spaces” in buildings, which are simply the parts of the building that facilitate air circulation in heating and air conditioning systems. This designation simply means that the cable has been engineered to be buried without any kind of outside protection.
Can I use riser cable in my house?
You can always substitute a higher rated cable, so for example, you can use plenum anywhere, riser can be used even if not between floors, etc.
How do you identify plenum cable?
Look for CMP(means Communications Plenum Cable) ,CL3P(Shielded Multi-Conductor Plenum Security Cable) , or CL2P(Class 2 plenum cable ) marked on the cable. Plenum cable is covered with a fire proof plastic layer of either a low-smoke polyvinyl chloride (PVC) or a fluorinated ethylene polymer (FEP).
Is plenum rated cable required in conduit?
Do you need plenum cable if it’s in conduit? If you’re using plenum-rated conduit, you don’t need to use plenum-rated cable. This is true even if the conduit is in a plenum space. The most common types of plenum conduit are innerduct (often used for fiber runs) and metal.
What is the difference between plenum and PVC cable?
What is the difference between PVC and Plenum cable? PVC (Polyvinyl Chloride) is what your standard Category 5e and Category 6 cable jacket is constructed of. Plenum cable is made of Teflon or FEP which gives off much less poisonous gas than PVC when it burns.
What is the difference between plenum and non plenum cable?
Non-plenum Cable Explanation Non-plenum cable usually serves to run through non-air circulating areas. Non-plenum includes riser rated cable, and other rated cables like CM cable, etc. Thus, plenum cable can replace riser cable, but not the other way around. And the price of riser cable is less than plenum cable.
How do I know if I have a plenum ceiling?
What determines if the space above a suspended (drop) ceiling is a plenum? A plenum ceiling is one that uses the space between the top of the suspended ceiling and the bottom of the floor above to handle air for ventilation. Consult the local code authority to confirm that a suspended ceiling is a plenum.
What is the difference between a plenum and a duct?
As nouns the difference between duct and plenum is that duct is a pipe, tube or canal which carries air or liquid from one place to another while plenum is (physics) a space that is completely filled with matter.
Does plenum mean shielded?
Plenum rated cables are jacketed with a fire-retardant plastic jacket of either a low-smoke polyvinyl chloride (PVC) or a fluorinated ethylene polymer (FEP) for less toxicity during a fire. This cable is shielded for use in heavy electronic environments.
Why is plenum cable more expensive?
When running cables within plenum spaces, plenum cables are a must. Because plenum cables are built to a higher fire resistance standard than riser cables, plenum cabling is more expensive than riser cabling.
Should shielding be grounded?
The shield must be grounded to be effective. The shield should be electrically continuous to maximize effectiveness, which includes cables splices. In shielded signal cables the shield may act as the return path for the signal, or may act as screening only.
