Siemens siprotec 7SD5 User Manual page 31

• Verification of the synchronous conditions or de-energized state also possible
• Also measurement via transformer
• Measuring voltages optionally phase-phase or phase-earth
Voltage Protection • Two overvoltage stages for the phase-earth voltages
(optional)
• Two overvoltage stages for the phase-phase voltages
• Two overvoltage stages for the positive sequence voltage, optionally with com-
• Two overvoltage stages for the negative sequence voltage
• Two overvoltage stages for the zero sequence voltage or any other single-phase
• Settable dropout to pickup ratios for the overvoltage protection functions
• Two undervoltage stages for the phase-earth voltages
• Two undervoltage stages for the phase-phase voltages
• Two undervoltage stages for the negative sequence voltage;
• Settable current criterion for undervoltage protection functions
Frequency • Monitoring for underfrequency (f<) and/or overfrequency (f>) with 4 frequency limits
Protection
(optional)
• Particularly insensitive to harmonics and abrupt phase angle changes
• Large frequency range (approx. 25 Hz to 70 Hz)
Fault Locator • Optionally single-ended (conventional) or double-ended fault location via communi-
• Initiated by trip command or reset of the fault detection
• Fault location output in Ohm, kilometers or miles and % of line length
• Output of the fault location also possible in BCD code
• Parallel line compensation can be selected
• Taking into consideration the load current in case of single-phase earth faults fed
• Possibility to take into account line asymmetry and of different line sections
Circuit Breaker • With definite time current stages for monitoring current flow through every pole of
Failure Protection
• With definite time monitoring time steps for single-pole and three-pole tripping
• Start by trip command of every internal protection function
• Start by external trip functions possible
• Single-stage or two-stage
• Short dropout and overshoot times
• End fault protection and pole discrepancy monitoring possible
7SD5 Manual
C53000-G1176-C169-1
before the manual closing of the circuit breaker, with separate limit values
pounding
voltage
and delay times that are independently adjustable
cation interfaces
from both sides (configurable)
the circuit breaker
1.3 Characteristics
31