The requirement forbidding fire alarm circuits from being T-tapped is intended to prevent which type of malfunction?

The requirement forbidding T-tapping in fire alarm circuits is primarily focused on maintaining the monitoring integrity of the installation conductors. T-tapping can compromise the circuit’s ability to accurately monitor the integrity of the connection because it introduces additional junctions where failures can occur. This can lead to an increased risk of open or short circuits, which would impair the system's overall reliability and effectiveness in detecting fire conditions.

By avoiding T-taps, the design ensures that each section of the circuit remains consistent in its electrical characteristics, allowing for better detection of faults like breaks or shorts. This is essential in maintaining a reliable fire alarm system that functions optimally during an emergency.