GE Feeder Management Relay 750

GE Multilin 750/760 Feeder Management Relay 5-21
5 SETPOINTS 5.4 S3 LOGIC INPUTS
5
5.4.3 BREAKER FUNCTIONS
PATH: SETPOINTS ÖØ S3 LOGIC INPUTS ÖØ BRKR FUNCTIONS
The following logic functions are used to determine whether the circuit breaker is open, closed, or disconnected from the
main power circuit, as monitored by auxiliary contacts on a drawout breaker racking mechanism, or on the associated iso-
lating disconnect switches on a fixed circuit breaker.
If neither the 52a or 52b contacts are installed then the following functions cannot be performed:
• Monitoring of breaker position
• Breaker Operation Failure
• Feedback control of Trip (Output Relay 1) and Close (Output Relay 2) relays
• Trip/Close Coil Supervision Without Permissive
• Manual close feature blocking
• Autoreclose
• Transfer
It is strongly recommended that the Breaker Operation Failure alarm be enabled when either 52a or 52b
breaker auxiliary contacts are installed.
Breaker logic functions must be assigned to Logic Inputs 1 to 14 as they must only be contacts.
The
52a CONTACT and 52b CONTACT setpoints are used to monitor the 52/a and 52/b contacts. The following table deter-
mines how these contacts affect the breaker state:
When asserted, the logic input assigned by the BRKR CONNECTED setpoint indicates that the breaker is connected to the
primary system. When the breaker is determined to be disconnected, the breaker state is shown to be neither open nor
closed. For further information regarding operation with only one auxiliary breaker contact, see Section 4.1.2: LED Status
Indicators on page 4–2.
 BRKR FUNCTIONS
 [ENTER] for more
52a CONTACT:
Disabled
Range: Input 1 to Input 20, Disabled
52b CONTACT:
Disabled
Range: Input 1 to Input 20, Disabled
BRKR CONTACT:
Disabled
Range: Input 1 to Input 20, Disabled
52/A CONTACT
INSTALLED?
52/B CONTACT
INSTALLED?
INTERPRETATION
Yes Yes 52a closed indicates breaker is closed
52b closed indicates breaker is open
Yes No 52a closed indicates breaker is closed
52a open indicates breaker is open
No Yes 52b open indicates breaker is closed
52b closed indicates breaker is open
No No Breaker status unknown
ENTER
ESCAPE
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ð
MESSAGE
ESCAPE
MESSAGE
ESCAPE
CAUTION
CAUTION
Courtesy of NationalSwitchgear.com