GE L90 Instruction Manual page 151

CHAPTER 4: INTERFACES
The status indicators in the first column are as follows:
• IN SERVICE — This LED indicates that control power is applied, all monitored inputs, outputs, and internal systems are
OK, and that the device has been programmed
• TROUBLE — This LED indicates that the relay has detected an internal problem
• TEST MODE — This LED indicates that the relay is in test mode. For more information, see the Test Mode section in the
Settings chapter.
• TRIP — This LED indicates that the FlexLogic operand serving as a trip switch has operated. This indicator always
latches; as such, a reset command must be initiated to allow the latch to reset.
• ALARM — This LED indicates that the FlexLogic operand serving as an alarm switch has operated. This indicator is
never latched.
• PICKUP — This LED indicates that an element is picked up. This indicator is never latched.
The event-cause indicators in the first column are as follows.
Event-cause LEDs are turned on or off by protection elements that have their respective target setting selected as either
"Enabled" or "Latched." If a protection element target setting is "Enabled," then the corresponding event-cause LEDs
remain on as long as the operate operand associated with the element remains asserted. If a protection element target
setting is "Latched," then the corresponding event-cause LEDs turn on when the operate operand associated with the
element is asserted and remain on until the
All elements that are able to discriminate faulted phases can independently turn off or on the phase A, B, or C LEDs. This
includes phase instantaneous overcurrent, phase undervoltage, and so on. This means that the phase A, B, and C operate
operands for individual protection elements are ORed to turn on or off the phase A, B, or C LEDs.
• VOLTAGE — This LED indicates voltage was involved
• CURRENT — This LED indicates current was involved
• FREQUENCY — This LED indicates frequency was involved
• OTHER — This LED indicates a composite function was involved
• PHASE A — This LED indicates phase A was involved
• PHASE B — This LED indicates phase B was involved
• PHASE C — This LED indicates phase C was involved
• NEUTRAL/GROUND — This LED indicates that neutral or ground was involved
The user-programmable LEDs consist of 48 amber LED indicators in four columns. The operation of these LEDs is user-
defined. Support for applying a customized label beside every LED is provided. Default labels are shipped in the label
package of every L90, together with custom templates. The default labels can be replaced by user-printed labels.
User customization of LED operation is of maximum benefit in installations where languages other than English are used
to communicate with operators. See the User-Programmable LEDs section in chapter 5 for the settings used to program
the operation of the LEDs on these panels.
4.2.7.2 Standard faceplate
The standard faceplate consists of three panels with LED indicators, keys, and a communications port. The
used to reset any latched LED indicator or target message, once the condition has been cleared (these latched conditions
can also be reset via the
SETTINGS  INPUT/OUTPUTS  RESETTING
computer.
The keys are used by the breaker control feature.
USER
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
button on the front panel is pressed after the operand is reset.
RESET
menu). The RS232 port is for connection to a
FRONT PANEL INTERFACE
key is
RESET
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