Siemens SIPROTEC 4 User Manual page 28

Introduction
1.3 Characteristics
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Overcurrent element with definite time or inverse time delay
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For inverse time overcurrent protection, characteristics according to IEC or ANSI standards, one userde-
fined and two logarithmic inverse current/time characteristics are available
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Direction determination with zero sequence quantities(Ι
nation
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Any element can be set as directional or non-directional — forward sensing directional, or reverse
sensing directional
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Directional characteristic curve adjustable
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Optionally applicable as additional ground fault protection.
Intermittent Ground Fault Protection
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Detects and accumulates intermittent ground faults
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Tripping after configurable total time.
Directional intermittent ground fault protection
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Detects intermittent ground faults
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Direction determination
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Tripping after settable number of intermittent re-ignitions
Automatic Reclosing 79
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Single-shot or multi-shot
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With separate dead times for the first and all succeeding shots
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Protective elements that initiate automatic reclosing are selectable. The choices can be different for
phase faults and ground faults
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Separate programs for phase and ground faults
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Interaction to time overcurrent protection element and ground fault elements. They can be blocked in
dependence of the reclosing cycle or released instantaneously
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Synchronous reconnection is possible (only for 7SJ623, 7SJ624, 7SJ625, 7SJ626 und 7SJ64) in combina-
tion with the integrated synchronization function..
Fault Location
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Initiation by trip command, external command or dropout of pickup
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Calculation of the fault distance and output of the fault location in ohms (primary and secondary) and in
kilometers or miles
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Up to three line sections can be configured.
Breaker Failure Protection 50 BF
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By checking the current and/or evaluating the circuit breaker auxiliary contacts
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Started by any integrated protection function that trips
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Initiation possible via a binary input from an external protective device.
Flexible Protective Functions
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Up to 20 customizable protection functions with three-phase or single-phase operation
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Any calculated or directly measured quantity can be evaluated on principle
•
Standard protection logic with definite time characteristic
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, V ), wattmetric ground fault direction determi-
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SIPROTEC 4, 7SJ62/64, Manual
C53000-G1140-C207-8, Edition 08.2016