GE D90 Plus Instruction Manual page 76

FRONT PANEL OVERVIEW
Self-test page
68
Figure 45: Annunciator alarm sequence
The annunciator states are described in the following table.
Table 3: Annunciator states
Line Process
1 Normal
2 Abnormal
3A Abnormal
3B Normal
4 Normal
5 Abnormal
6 Normal
The visual indications are displayed as follows.
• Off: grey text on a darker grey background.
• On: bright white text on a colored background.
• Fast flash: Alternating between the off state and the on state two times per second.
• Slow flash. Alternating between the off state and the on state one time per second
In the event of an alarm, the page containing the alarm will be promoted to active page. If
there are multiple pages with alarms, the page with the lowest page number is promoted.
If there are alarms on multiple pages, and alarms on some pages have already been
acknowledged (but not cleared) by the user, then the pages with active alarms move ahead
of the pages that have acknowledged alarms. The user will always have to navigate
through the pages of alarms to view them.
Display of alarm pages is prioritized according to active window (unacknowledged or
flashing alarm) and page number (for example, if two pages have an unacknowledged
alarm, the page with the lowest number will automatically be promoted as the displayed
page).
The self-test page displays any active self test alarms as well as the time of occurrence
and the severity of the alarm (yellow for non-critical and red for critical).
Pushbutton
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Acknowledge
Acknowledge
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Reset
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACES
Sequence Visual indication
Normal Off
Alarm Fast flash
Acknowledged On
To line 4 To line 4
Ringback Slow flash
To line 2 To line 2
Normal Off