What characteristic does a plenum rated cable have?

A plenum rated cable is specifically designed for use in spaces that facilitate air circulation for heating and air conditioning systems, known as plenums. One of the primary characteristics of plenum rated cables is low smoke emission. This feature is critical because, in the event of a fire, cables that produce a high amount of smoke can pose serious dangers to occupants and hinder visibility and escape routes. Plenum rated cables are made with materials that minimize smoke generation when exposed to flames, significantly improving safety in building environments.

The other characteristics listed, while important in various contexts, do not specifically pertain to what defines a plenum rated cable. For example, while resistance to crushing might be relevant for cable durability, it does not address fire safety. Water resistance is important for cables in outdoor or damp environments but does not relate to plenums. Similarly, high fiber count pertains to the capacity of the cable and is not a defining feature of plenum rated cables. Thus, the focus on low smoke emission underscores the critical safety standard these cables must meet in air-handling spaces.