plenum or no plenum

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killerasp

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i got into a debate with this guy. we are coming up with ideas on rewiring the office. we need to run cat5e through the walls. im saying use plenum, he says dont. what do you all think.
 
well technically, you want to check your fire codes and such first..as they may or may not require plenum....but if it is in an office, I would recommend plenum so that in the terrible event of a fire, your wire will not emit toxic fumes while burning...
 
Last I heard, you were supposed to use plenum if you were running wire over the fake ceilings, otherwise use the normal stuff.

Granted, this was from college text book years ago, so they very likely have come up with local codes that supercede this.
 
As said, check with your building's wiring and fire codes - they may have specific information to follow.

However, the "standard" rule of thumb is that you should run plenum wiring through walls/ceilings/floors - any type of real infrastructure wiring. Then from the jackboxes in the room to the computer, or from the patch panel to the switch, you can run non-plenum wire.
 
I would also say to check the local codes. I know here in Cleveland, the city requires that only plenum cable is used. The general rule of thumb is that when you run cable in a plenum space (the area above a drop ceiling when used for an air return), you use plenum cable. Otherwise you may be able to use PVC, but for most commerical applications you are better off in the long run with plenum.
 
same advice as the others have given. check with your local fire codes. FYI the chances of this are rare, but if a building inspector or fire inspector comes into your office and notices non-plenum cable where there should be plenum he can red flag your ass so quick it will make your head spin. Basically the office would have to shutdown until the plenum cable is installed. its not a pretty picture
 
Something tells me that flagg has experienced this first hand...
 
Plenum is to be used when you have drop down ceilings, and there are air ducts up in there. It's a special coating that does not release toxic fumes when it's burning, and the fire code laws revolve around if there are air ducts up there or not which might spread the fumes faster when burning occurs.
 
Hmmmmm....

Plenum-rated cable doesn't give off the toxic fumes that normal insulation will when it burns. Thus, you use it where the space is used as a plenum/duct to reduce the noxious affects of smoke during a fire. Your typical office drop-ceiling plenum space is used as the air-return for the HVAC system, and consequently needs to always have plenum-rated wire used. If the HVAC system uses actual duct for the air return, then a plenum-rated cable is not typically required.

Of course, local codes can vary, and your mileage may vary. But that is the principle behind plenum-rated cable.
 
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