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5.7 CONTROL ELEMENTS
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, the interval between change-of-state of the
operand (from 0 to 1) and contact separation should be measured 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. Cor-
rection 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
menus.
BREAKER 1(2)
•
BKR 1 ARC AMP INT-A(C): Select the same output operands that are configured to operate the output relays used to
trip the breaker. In three-pole tripping applications, the same operand should be configured to initiate arcing current
calculations for poles A, B and C of the breaker. In single-pole tripping applications, per-pole tripping operands should
be configured to initiate the calculations for the poles that are actually tripped.
•
BKR 1 ARC AMP DELAY: This setting is used to program the delay interval between the time the tripping sequence is
initiated and the time the breaker contacts are expected to part, starting the integration of the measured current.
•
BKR 1 ARC AMP LIMIT: Selects the threshold value above which the output operand is set.
5
5-212
Breaker
Contacts
Initiate
Part
Programmable
Start Delay
Start
Integration
Figure 5–112: ARCING CURRENT MEASUREMENT
D30 Line Distance Protection System
ACTUAL VALUES
RECORDS
Arc
Extinguished
Total Area =
Breaker
Arcing
Current
(kA·cycle)
100 ms
Stop
Integration
5 SETTINGS
MAINTENANCE
GE Multilin
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