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4.1 FRONT PANEL INTERFACE
a) DESCRIPTION
The front panel indicators are grouped into three columns. The 750/760 Status column indicates the state of the relay; the
System Status column indicates the state of the breaker and the system; and the Output Status column indicates the state
of the output relays. These LED indicators can be tested by pressing
below, the color of each indicator conveys its importance.
G = Green: General Condition
A = Amber: Alert Condition
R = Red: Serious Alarm or Important Status
b) 750/760 STATUS LED INDICATORS
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RELAY IN SERVICE: This indicator will be on continuously if the relay is functioning normally and no major self-test
errors have been detected. During operation the relay continuously performs various self tests and if a major self-test
fails, the indicator will be turned off, all output relays will be de-energized, and the Self-Test Warning LED will be turned
on. This indicates a complete loss of protection. See the self-test warning section later in this chapter.
•
TRIP: This indicator flashes when the relay detects a trip condition and operates the Trip Relay to open the breaker.
After the initiating fault has been cleared, this LED can be turned off with a reset.
4
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ALARM: While the relay is detecting an alarm condition, this indicator will flash. Even if latched output relays are pro-
grammed to operate with the alarm, the indicator will automatically turn off if the alarm condition clears. Such output
relays will remain in the operated state until a reset is performed.
Latched Alarm: This relay flashes while the relay is detecting an alarm condition. After the condition clears, the
indicator remains illuminated and can be turned off with a reset.
NOTE
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PICKUP: For the purpose of testing and calibration verification, this indicator will light steady when any protection fea-
ture has its pickup threshold exceeded. Eventually, if the fault condition persists, a trip will be issued by the relay. If the
measured parameter drops below its pickup level, the indicator will turn off.
•
SETPOINT GROUP 1 to 4: These indicators are flashing if the corresponding group is selected for editing and/or dis-
play; they are continuously on if the corresponding group is providing settings for the protection elements.
c) SYSTEM STATUS LED INDICATORS
The Open and Closed Status Indicator colors are interchangeable at the time of placing a 750/760 order.
NOTE
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BREAKER OPEN: When the breaker is open, this indicator will be on continuously.
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BREAKER CLOSED: When the breaker is closed, this indicator will be on continuously.
Breaker status indication is based on the breaker 52a and 52b contacts. With both contacts wired to the relay, the
closed status is determined by a closed 52a contact and the open status is determined by a closed 52b contact. If both
52a and 52b contacts are open, due to a breaker being racked out of the switchgear, both the Breaker Open and
Breaker Closed LED Indicators will be off.
With a single 52a contact, it is impossible to distinguish between a breaker open state and a racked out breaker. In
both situations, the 52a contact will be open. With a single 52b contact, you cannot distinguish between a breaker
closed state and a racked out breaker. Likewise, the 52b contact will be open for both situations. To clarify this ambigu-
ity, the breaker connected function should be programmed to an additional logic input. When this additional input is
closed, a single 52a or 52b contact will show both breaker states. When the breaker is racked out, this additional
breaker connected input should be open. In this case, both breaker status indicators will be off.
•
RECLOSURE ENABLED (760 only): This indicator will be on continuously when autoreclosure is allowed to operate
as programmed. This is when the autoreclose function setpoint is enabled, and if used, the block reclosure logic input
is not asserted. Otherwise, this indicator will be off. Note that this indicator will always be in the opposite state of the
Reclosure Disabled LED Indicator.
•
RECLOSURE DISABLED (760 only): This indicator will be on continuously when autoreclosure is not allowed to oper-
ate as programmed. This is when the autoreclose function setpoint is disabled, or if used, the block reclosure logic
4-2
Courtesy of NationalSwitchgear.com
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750/760 Feeder Management Relay
4 USER INTERFACES
4.1.2 LED STATUS INDICATORS
when no trips or alarms are active. As shown
GE Multilin
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