Plenum rated cables are defined as cables routed through which space?

• A. Above-ceiling air circulation spaces.
• B. Underground tunnels.
• C. In-wall cavities.
• D. Underwater conduits.

Answer: (A)

Plenum-rated cables are intended for use in spaces that circulate building air as part of the HVAC system. These plenums are typically above suspended ceilings or under raised floors where air is moved to return or distribute conditioned air. Because smoke and toxic fumes can spread quickly in these air-handling spaces, cables installed there must meet stringent flame and smoke requirements. That’s why the correct description is cables routed through above-ceiling air circulation spaces. The other options aren’t air-handling plenums, so they don’t define plenum-rated installations.