GE L90 Instruction Manual page 578

CONTROL ELEMENTS CHAPTER 5: SETTINGS
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.
Breaker arcing currents and fault duration values are available under the
ACTUAL VALUES  RECORDS  MAINTENANCE 
menus.
BREAKER 1(4)
— Select the same output operands that are configured to operate the output relays used to trip the
BKR 1 ARC AMP INT-A(C)
breaker. In three-pole tripping applications, configure the same operand to initiate arcing current calculations for poles A,
B, and C of the breaker. In single-pole tripping applications, configure per-pole tripping operands to initiate the calculations
for the poles that are actually tripped.
— This setting is used to program the delay interval between the time the tripping sequence is
BKR 1 ARC AMP DELAY
initiated and the time the breaker contacts are expected to part, starting the integration of the measured current.
— Selects the threshold value above which the output operand is set.
BKR 1 ARC AMP LIMIT
2 2
— Selects a FLexLogic Operand to clear the accumulated I t values (kA -cycle), reset fault duration
BKR 1 CLR ARC AMPS
2
items (breaker operating time), clear ARCING AMPS (kA -cycle) and AMP MAX (kA) values of the last event.
— This setting specifies the maximum symmetrical interruption rating of the circuit breaker.
BKR 1 INTERUPTION RATING
Figure 5-202: Arcing current measurement
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5-354 L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL