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8.1 INTRODUCTION
The keys are divided into three groups:
1. The Command keys: SETTINGS [SET], INFORMATION [INF], ACTIONS [ACT] and [END]. These keys
begin or end a command sequence. They are discussed in detail later in this section.
2. The Control keys: ENTER [ENT], up-arrow [↑], down-arrow [↓], and CLEAR [CLR]. These keys may
cause the relay to take some action.
3. The Data Entry keys: all the numeric keys, the decimal point and the [INV] key. These keys are used to
enter data into the relay or answer prompts.
The keypad can be enabled or disabled by switch SW2 on the input board. If the switch is in the ON position,
the keypad is enabled; if the switch is in the OFF position, the keypad is disabled. Only the [CLR] key functions
when the keypad is disabled.
a) METERING/CLEAR KEY [CLR]
Depending on the current state of the display, the [CLR] key has the following uses: abort a key sequence in
progress; clear an error message; activate scrolling of metering; and display recorded trip data.
If the [CLR] key is pressed while entering data, all or part of the display will be blanked. If there is user-entered
data on the display, only the data will be blanked. For example, if the user is entering a Setting value or
responding to an Action prompt when the [CLR] key is pressed, only the user's input will be blanked; the name
of the setting or the prompt will remain on the display. If there is no user-entered data on the display when
[CLR] key is pressed, the entire display will be blanked and the relay screen will be displayed.
When a keypad error message is displayed, the [CLR] key must be pressed to remove it (all other keys are
ignored). When the error message is removed, the user is returned to the current operation being performed.
Pressing the [CLR] key while a TRIP message is displayed will produce the TRIP information on the LCD. Only
the target information (TRIP message ) and date/time of the trip for each of the accumulated faults are dis-
played, starting from the most recent fault (that is, the one whose TRIP message was on display before press-
ing the [CLR] key). The trip time resolution is one millisecond as shown below:
If the [CLR] key is pressed again, the target information and trip time/date date for the next most recent fault is
displayed. The user can scroll through all the accumulated trip information using the [CLR] key. The most
recent trip message will flash. Pressing the [CLR] key after the last trip will display the relay screen. Scrolling
8
through the trip information using arrow keys is not possible; thus the trip information may only be viewed from
the most recent to the oldest when using the [CLR] key.
Pressing the [CLR] key when the screen is blank or when the relay screen is displayed causes Present Values/
Metering to be displayed. Each screen of values is displayed for 4 seconds before proceeding to the next
screen. Screens containing breaker health present values are not displayed. After automatically scrolling
through all the screens, the display returns to the relay screen. The items displayed are described in Section
8.2.4: REQUEST PRESENT VALUES on page 8–21. The arrow keys cannot be used to scroll through the
present values.
Both the fault data display and the present value display are stopped by one of the following: TRIP, FAIL/
WARN message or a key being pressed.
8-
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#1
19:10:01.259
06/29/95
TRIP AB Z2 145.0MI
LPS-D Line Protection System
8 LOCAL USER INTERFACE
8.1.3 CONTROL KEYS
GE Power Management
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