CHAPTER 4: INTERFACES FRONT PANEL INTERFACED30 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL 4-194Figure 4-21: LED panel 1Status indicators• IN SERVICE — Indicates that control power is applied, all monitored inputs/outputs and internal systems are fine, therelay has been programmed• TROUBLE — Indicates that the relay has detected an internal problem• TEST MODE — Indicates that the relay is in test mode. For more information, see the Test Mode section in the Settingschapter.• TRIP — Indicates that the selected FlexLogic operand serving as a Trip switch has operated. This indicator alwayslatches; the reset command must be initiated to allow the latch to be reset.• ALARM — Indicates that the selected FlexLogic operand serving as an Alarm switch has operated. This indicator isnever latched.• PICKUP — Indicates that an element is picked up. This indicator is never latched.Event-cause indicatorsEvent-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 LEDsremain on as long as operate the operand associated with the element remains asserted. If a protection element targetsetting is “Latched,” then the corresponding event cause LEDs turn on when the operate operand associated with theelement is asserted and remain on until the RESET button on the front panel is pressed after the operand is reset.All elements that are able to discriminate faulted phases can independently turn off or on the phase A, B, or C LEDs. Thisincludes phase instantaneous overcurrent, phase undervoltage, and so on. This means that the phase A, B, and C operateoperands for individual protection elements are ORed to turn on or off the phase A, B, or C LEDs.• VOLTAGE — Indicates voltage was involved• CURRENT — Indicates current was involved• FREQUENCY — Indicates frequency was involved• OTHER — Indicates a composite function was involved• PHASE A — Indicates phase A was involved• PHASE B — Indicates phase B was involved• PHASE C — Indicates phase C was involved• NEUTRAL/GROUND — Indicates that neutral or ground was involvedUser-programmable indicatorsThe second and third panels provide 48 amber LED indicators whose operation is controlled by the user. Support forapplying a customized label beside every LED is provided.User customization of LED operation is of maximum benefit in installations where languages other than English are usedto communicate with operators. See the User-programmable LEDs section in chapter 5 for the settings used to programthe operation of the LEDs on these panels.PICKUPALARMTRIPTEST MODETROUBLEIN SERVICESTATUSUSER 3USER 2USER 1RESETNEUTRAL/GROUNDPHASE CPHASE BPHASE AOTHERFREQUENCYCURRENTVOLTAGEEVENT CAUSE842781A1.CDR
