Operator assistant's alarm summary dropped a low-priority alarm that preceded a trip
During a simulated fault sequence, the assistant grouped a low-priority communications alarm into 'routine noise'. That alarm was the first sign of the injected fault, and operators reading the summary missed it.
- Reproduction
- Load twin state ███.
- Run fault sequence ███ with the assistant's summary panel enabled.
- Compare the summary with the raw alarm list at T+4 minutes.
- Impact
- Operators lost about six minutes of warning in the exercise.
- Control
- Summaries show a count of suppressed alarms with a link to the raw list, and communications alarms on protection relays are never summarized.
- Retest
- All three injected sequences surfaced the first alarm in the summary.