Circuit Integrity (CI) cables can only be installed in which situation?

Circuit Integrity (CI) cables are designed to maintain their functionality during a fire, which is crucial for the operation of fire alarm systems in emergency situations. The correct choice indicates that these cables can only be installed where specifically listed and marked. This means that the installation must adhere to specific manufacturer requirements and relevant codes, which dictate acceptable locations and conditions for CI cables to ensure their performance under fire conditions.

This requirement emphasizes the importance of following guidelines that verify the intended use and capabilities of the cables. Such regulations help ensure that the integrity of the fire alarm system is maintained even in the event of a fire, thereby contributing to overall safety.

In other situations, such as portable fire alarm systems, ducts, plenums, or exposed surfaces, the usage of CI cables may not be appropriate or compliant with safety standards, as they could be subject to different risks or failures that are not addressed by the specific design of CI cables. Therefore, it is crucial to adhere strictly to the listings and markings issued by manufacturers to guarantee the cable's intended protective functioning in a fire scenario.