GE Multilin L60, Инструкция по эксплуатации

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5-254 L60 Line Phase Comparison System GE Multilin
5.6 CONTROL ELEMENTS 5 SETTINGS
5
• TRIP PILOT PRIORITY : This setting is used to set an interval equal to the inter-relay channel communications time,
plus a margin, during which outputs are not asserted. This delay permits fault identification information from a remote
terminal to be used instead of local data only.
• REVERSE FAULT : Use this setting to guarantee accuracy of single-pole tripping under evolving external to internal
faults. When a close-in external fault occurs, the relay is biased toward very fast operation on a following internal fault.
This is primarily due to depressed voltages and elevated currents in response to the first, external fault. The phase
selector can exhibit some time lag compared to the main protection elements. This can potentially result in a spurious
three-pole operation on a single-line-to-ground internal fault. Delaying tripping on internal faults that follow detection of
reverse faults solves the problem.
As long as the operand indicated under this setting is asserted the trip action is delayed by
TRIP DELAY ON EVOLV
FAULTS
time. Typically this operand should combine reverse zone indications (such as zone 4 pickup) with a half-cycle
pickup delay, and two-cycle dropout delay. This setting should be used only in single-pole tripping applications, when
evolving faults are of importance, and slightly delayed operation on evolving faults could be traded for enhanced accu-
racy of single-pole tripping.
• TRIP DELAY ON EVOLV FAULTS : Use this setting in conjunction with the
REVERSE FAULT
setting (see above). Typi-
cally this value is set around half a power system cycle. Use it only in single-pole tripping applications, when evolving
faults are of importance, and slightly delayed operation on evolving faults could be traded for enhanced accuracy of
single-pole tripping.
• BKR Φ A OPEN , BKR Φ B OPEN , and BKR Φ C OPEN : This settings are used to select an operand to indicates that
phase A, B, or C of the breaker is open, respectively.