Which condition is critical for the operation of open circuit detection in an intrusion system?

Open circuit detection in an intrusion system is primarily concerned with monitoring the integrity of the circuit itself. For this detection mechanism to function effectively, the circuits need to be intact. If a circuit is open—meaning there is a break in the connection—this can indicate a potential intrusion or tampering. The system relies on the complete electrical path to ensure it can accurately detect any unauthorized access or breaches.

In contrast, powering sensors or disarming alarms does not directly influence open circuit detection. While it is essential that sensors are operational and personnel are trained in system protocols, neither of these factors ensures the integrity of the circuits. Thus, maintaining intact circuits is critical for an intrusion detection system's ability to identify and respond to threats.