GE LPS-O Instruction Manual page 170

8.1 INTRODUCTION
The keys are divided into three groups:
1. The Command keys: SETTINGS [SET], INFORMATION [INF], ACTIONS [ACT] and [END], begin or end
a command sequence. These keys will be discussed in detail in this section.
2. The Control keys: ENTER [ENT], UP-ARROW (↑), DOWN-ARROW (↓) AND CLEAR [CLR] may cause
the relay to take some action.
3. The Data Entry keys: all the numeric keys, the decimal point and the [INV] key enter data into the relay or
answer prompts.
The keypad can be enabled or disabled by SW2 on the input board. If the switch is in the "ON" position, the
keypad is enabled and if the switch is in the "OFF" position, the keypad is disabled. Only the [CLR] key func-
tions 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: aborting a key sequence in
progress; clearing an error message; and activating 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 user must press the [CLR] key to remove the error message
(all other keys will be ignored). When the error message is removed, the user will be 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 user presses the [CLR] key again, the target information and trip time and date for the next most recent
8
fault is shown on the display. 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 through the TRIP information using arrow keys is not possible – as such, 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 the Present Val-
ues/Metering screens 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 scroll-
ing through all the screens, the display returns to the relay screen. The items displayed are described later in
this section (see 8.2.4: REQUEST PRESENT VALUES on page 8–20). The user cannot use the arrow keys 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.
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TRIP AB Z2 145.0MI
LPS-O Line Protection System
8 LOCAL USER INTERFACE
8.1.3 CONTROL KEYS
GE Power Management