Siemens SIPROTEC 7SD610 Manual page 25

Restricted Earth Fault Protection
• Earth fault protection for earthed transformer windings
• Short tripping time
• High sensitivity for earth faults
• High stability against external earth faults using the magnitude and phase relationship of through-flowing
earth current
External Direct and Remote Tripping
• Tripping of the local end by an external device via binary input.
• Tripping of the remote end by internal protection functions or by an external device via binary input
Transmission of Information
• Transmission of measured values from the other end of the protected object.
• Transmission of up to 4 fast commands to all remote ends (optional)
Time Overcurrent Protection
• Selectable as emergency function during protection data communication failure or as backup function or as
both
• Maximal three definite time stages and one inverse time stage each for phase currents and earth current
• One directional definite time stages and one directional inverse time stage, each for phase currents and
earth current
• For inverse-time overcurrent protection select from various characteristics based on several standards
• Blocking capability e.g. for reverse interlocking with any stage
• Instantaneous tripping by any stage when switching onto a fault
High Current Switch-onto-Fault Protection
• Fast tripping for all faults on 100 % line length
• Selectable for manual closure or following each closure of the circuit breaker
• With integrated line energization detection.
Automatic Reclosure Function (optional)
• For reclosure after 1-pole, 3-pole or 1-pole and 3-pole tripping
• Single or multiple reclosure (up to eight reclosure attempts)
• With separate action time setting for the first 4 reclose attempts, optionally without action times
• With separate dead times after 1-pole and 3-pole tripping, separate for the first four reclosure attempts
• With the option of an adaptive dead time: in this case the one device controls the automatic reclosure cycles
whilst at the other line end the automatic reclosure solely depends on the one controlling device. The criteria
used are voltage measurement and/or the transmitted CLOSE command (Remote-CLOSE)
• Automatic reclosure controlled optionally by protection start with separate dead times after single, two and
three-pole starting
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
Introduction
1.3 Characteristics
25