Under what condition can non-plenum rated cables be used in a plenum?

Non-plenum rated cables can be used in a plenum space when they are installed in a plenum raceway. Plenum spaces are areas used for air circulation in heating and air conditioning systems, and they require specific types of materials to mitigate fire hazards and reduce the risk of smoke development. Plenum-rated cables are specifically designed to meet these strict safety standards.

When non-plenum rated cables are placed inside a plenum raceway, the enclosure helps contain and protect the cables, limiting the potential fire risks associated with their use. This means that, as long as the non-plenum rated cables are safely housed within a raceway that adheres to fire safety regulations and prevents any materials from coming into direct contact with the air flow, they can be utilized in plenum areas. This option ensures compliance with safety codes while allowing some flexibility in the types of cabling used in situations where plenum-rated options might not be readily available or necessary.