Siemens 7SC80 Manual page 56

Functions
2.1 General
Correction of the Phase Sequence for the Voltage Transformers
You can adapt the relation between the voltage measurands and the physical measuring inputs to the actual
conditions at address 338 VT Ph. Connect..
Distance Unit (Power System)
Address 215 Distance Unit allows you to specify the distance unit (km or Miles) for the fault locator. In
the absence of a fault locator or if this function has been removed, this parameter is of no importance.
Changing the distance unit does not imply an automatic conversion of the setting values that are dependent
on the distance unit. These have to be re-entered at the respective addresses.
Parameter 215 is also used to make the corresponding measured value (m or ft) visible for GPS parameter
setting. The parameter is only visible if GPS or the fault locator are available.
Trip and Close Command Duration (Breaker)
In address 210 the minimum trip command duration TMin TRIP CMD is set. This setting applies to all protec-
tion functions that can initiate tripping
Current Flow Monitoring (Breaker)
Address 212 BkrClosed I MIN corresponds to the threshold value of the integrated current flow moni-
toring system. This parameter is used by several protection functions (e.g. voltage protection with current
criterion). If the set threshold current is exceeded, the circuit breaker is considered closed.
The threshold value setting applies to all three phases, and must take into consideration all used protection
functions.
The pickup threshold for the breaker failure protection is set separately (see
Two-phase Time Overcurrent Protection (Protection Operating Quantities)
The two-phase overcurrent protection functionality is used in grounded or compensated systems where inter-
action of three-phase devices with existing two-phase protection equipment is required. Via parameter 250
50/51 2-ph prot the time overcurrent protection can be configured to two or three-phase operation. If the
parameter is set to ON, the value 0 A instead of the measured value for Ι
threshold comparison so that no pickup is possible in phase B. All other functions, however, operate in three
phases.
Ground Fault (Protection Operating Quantities)
With parameter 613 Gnd O/Cprot. w. you can specify whether the directional and the non-directional
ground fault protection, the breaker failure protection, or the voltage transformer monitoring use the meas-
ured values Ignd (measured) or the values 3I0 (calcul.) calculated from the three phase currents. In
the first case, the measured quantity at the fourth current input is evaluated. In the latter case, the summation
current is calculated from the three phase current inputs. If the device features a sensitive ground current
input (measuring range starts at 1 mA), the ground fault protection always uses the calculated variable 3I0. In
this case, parameter 613 Gnd O/Cprot. w. is not available.
Voltage Protection (Protection Operating Quantities)
Parameters 614 OP. QUANTITY 59 and 615 OP. QUANTITY 27 define the quantities used by the voltage
protection.
In a 3-phase connection, overvoltage protection optionally uses the following quantities:
•
Fundamental harmonic of the largest of the phase-to-phase voltages (Vphph)
•
Fundamental harmonic of the largest of the phase-to-ground voltages (Vph-n)
•
Positive sequence voltage (V1)
56
2.18.2 Setting Notes).
is used permanently for the
B
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017