Siemens SIPROTEC 7UT613 series Manual page 24

1 Introduction
Busbar Protection
Earth Fault Differ-
ential Protection
High-impedance
Unit Protection
Tank Leakage Pro-
tection
Time Overcurrent
Protection for
Phase Currents and
Residual Current
24
• 1-phase differential protection for a busbar with up to 9 or 12 feeders (depending
on the version)
• Either one relay per phase or one relay connected via interposed summation
current transformers
• Tripping characteristic with current restraint
• Short tripping time
• Insensitivity to DC components and current transformer saturation
• High level of stability even with different degrees of current transformer saturation
• Monitoring of the current connections with operation currents.
• Earth fault protection for earthed transformer windings, generators, motors, shunt
reactors, or starpoint formers
• Short command duration
• High sensitivity for earth faults within the protected zone
• High stability against external earth faults using the magnitude and phase relation-
ship of through-flowing earth current.
• 2 earth-fault differential protection functions possible
• Highly sensitive fault current detection using a common (external) burden resistor
• Short tripping time
• Insensitive against DC components and current transformer saturation
• High stability with optimum matching
• Suitable for earth fault detection on earthed generators, motors, shunt reactors, and
transformers, including auto-transformers, with or without earthed starpoint.
• Suitable for any voltage measurement (via the resistor current) for application of
high-impedance unit protection
• For transformers or reactors the tank of which is installed isolated or with high re-
sistance
• Monitoring of the current flowing between the tank and ground
• Can be connected via a „normal" current input of the device or the special highly
sensitive current input (3 mA smallest setting).
• Two definite time delayed overcurrent stages for each of the phase currents and the
residual (threefold zero sequence) current, can be assigned to any of the sides of
the protected object or to any measuring point
• Additionally, one inverse time delayed overcurrent stage for each of the phase cur-
rents and the residual current
• Selection of various inverse time characteristics of different standards is possible,
alternatively a user defined characteristic can be specified
• The stages can be combined as desired, different characteristics can be selected
for phase currents on the one hand and the residual current on the other
• External blocking facility for any stage (e.g. for reverse interlocking)
7UT613/63x Manual
C53000-G1176-C160-2