Siemens 7SC80 Manual page 237

Address 8102 BALANCE V-LIMIT determines the limit voltage (phase-to-phase) above which the voltage
symmetry monitor is effective. Address 8103 BAL. FACTOR V is the associated symmetry factor; that is, the
slope of the symmetry characteristic curve.
Address 8104 BALANCE I LIMIT determines the limit current above which the current symmetry monitor is
effective. Address 8105 BAL. FACTOR I is the associated symmetry factor; that is, the slope of the
symmetry characteristic curve.
Address 8106 Σ I THRESHOLD determines the limit current above which the current sum monitoring is acti-
vated (absolute portion, only relative to Ι
current) for activating the current sum monitor is set at address 8107 Σ I FACTOR.
NOTE
i
i
Current sum monitoring can operate properly only when the three phase currents and at the fourth current
measuring input (Ι
System Data 1).
NOTE
i
i
The connections of the ground paths and their adaption factors were set when configuring the general
Power System Data. These settings must be correct for the measured values monitoring to function prop-
erly.
Measured value monitoring can be set to ON or OFF at address 8101 MEASURE. SUPERV.
Broken Conductor Detection
At address 5501 46BC, you can switch the broken conductor detection ON or OFF.
Address 5502 T 46BC allows you to enter the waiting time after detection of a broken conductor until the
broken conductor indication is sent.
At address 5503 Curr. Factor BC, you can set the adaptation coefficient for current values and at address
5504 Volt. Factor BC the adaptation coefficient for voltages. This coefficient is used to determine a refer-
ence value from the measured values in order to detect a broken conductor.
At address 5505 CT Location and address 5506 VT Location, you specify the arrangement of the current
transformers or voltage transformers relating to the transmission towers (Direction 1 or Direction 2).
At address 5506 VT Location, you enter the arrangement of the voltage transformers relating to the trans-
mission towers.
Inrush Current Detection
If large inrush currents are expected when using the protection device at transformers, an inrush detection
function can be activated for the directional and non-directional overcurrent elements in the 7SC80.
Inrush current detection is active if address 122 InrushRestraint was set to Enabled. If this function is
not required, it is set to Disabled.
At address 2201 INRUSH REST., the function is switched ON or OFF for all elements. Furthermore, you can
enable or disable the inrush current detection for each element. The parameters for the function are assigned
to the overcurrent protection elements. See Section
information.
Address 2206 INRUSH DET. BY allows you to set the inrush current detection mode. If set to Phase,
blocking affects the phase in which the inrush current was detected. When the setting is Cross, all phases
and the ground path are blocked. With the setting Sum, all phase currents are used to detect the inrush
current.
The inrush restraint is based on the evaluation of the 2nd harmonic present in the inrush current. Upon
delivery from the factory, a ratio Ι
be changed. The setting value is identical for all phases and ground. However, the component required for
restraint may be adjusted to system conditions in address 2202 2nd HARMONIC. To provide more restraint in
exceptional cases, where energizing conditions are particularly unfavorable, a smaller value can be set in the
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017
). The relative portion (relative to the maximum conductor
Nom
) for ground current the ground current of the protected line are connected (see Power
N
/Ι of 15 % is set. Under normal circumstances, this setting will not need to
2f f
2.2.12 Setting Notes and 2.3.10 Setting Notes
Functions
2.12 Monitoring Functions
for more
237