4.1.1-4 Darkboard Configuration

Alarms and setpoints should be designed so that only parameters and conditions that fall outside of the normal and expected range and that require operator attention or action are in the alarm state.

Additional Information:
This has traditionally been referred to as the darkboard concept and is applicable when at full power operation. In practice it may be difficult in some plants to completely achieve a darkboard but that should be the goal. If the alarm system does not have this capability for all operating conditions, it should be in effect when all systems are lined up in their most typical configuration for full- power operation. This concept has implications for the plant's operating philosophy as well, including issues such as (1) repairing failed equipment expeditiously, (2) taking corrective actions for instrument drifts that cause alarms, and (3) correcting conditions that frequently lead to repeat alarms.