GE L60 Instructions Manual page 530

Line phase comparison system
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CONTROL ELEMENTS
5.7.9.2 Breaker arcing current
SETTINGS  CONTROL ELEMENTS  MONITORING ELEMENTS  BREAKER 1(2) ARCING CURRENT
 BREAKER 1
 ARCING CURRENT
5
There is one breaker arcing current element available per CT bank, with a minimum of two elements. This element
calculates an estimate of the per-phase wear on the breaker contacts by measuring and integrating the current squared
passing through the breaker contacts as an arc. These per-phase values are added to accumulated totals for each phase
and compared to a programmed threshold value. When the threshold is exceeded in any phase, the relay can set an
output operand to "1." The accumulated value for each phase can be displayed as an actual value.
The operation of the scheme is shown in the following logic diagram. The same output operand that is selected to operate
the output relay used to trip the breaker, indicating a tripping sequence has begun, is used to initiate this feature. A time
delay is introduced between initiation and the starting of integration to prevent integration of current flow through the
breaker before the contacts have parted. This interval includes the operating time of the output relay, any other auxiliary
relays, and the breaker mechanism. For maximum measurement accuracy, measure the interval between change-of-state
of the operand (from 0 to 1) and contact separation for the specific installation. Integration of the measured current
continues for 100 ms, which is expected to include the total arcing period.
The feature is programmed to perform fault duration calculations. Fault duration is defined as a time between operation of
the disturbance detector occurring before initiation of this feature, and reset of an internal low-set overcurrent function.
Correction is implemented to account for a non-zero reset time of the overcurrent function.
5-322
 VT FUSE FAILURE 2
 OPEN POLE
 THERMAL OVERLOAD
 PROTECTION
 BROKEN CONDUCTOR
BKR 1 ARC AMP
FUNCTION: Disabled
BKR 1 ARC AMP
SOURCE: SRC 1
BKR 1 ARC AMP INT-A:
Off
BKR 1 ARC AMP INT-C:
Off
BKR 1 ARC AMP
DELAY: 0.000 s
BKR 1 ARC AMP LIMIT:
1000 kA2-cyc
BKR 1 INTERRUPTION
RATING: 31.5 kA
BKR 1 CLR ARC AMPS:
Off
BKR 1 ARC AMP BLOCK:
Off
BKR 1 ARC AMP
TARGET: Self-reset
BKR 1 ARC AMP
EVENTS: Disabled
See page 5-335
See page 5-338
See page 5-341
Range: Disabled, Enabled
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: FlexLogic operand
Range: FlexLogic operand
Range: 0.000 to 65.535 s in steps of 0.001
2
Range: 0 to 50000 kA
-cycle in steps of 1
Range: 0.0 to 100.0 kA in steps of 0.1
Range: FlexLogic operand
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS

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