Siemens SIPROTEC 7SJ62 Manual page 291

Note
With regard to the phase-selective pickup messages, a special behavior is observed in the three-phase voltage
protection with phase-to-phase variables, because the phase-selective pickup message "Flx01 Pickup Lx" is
allocated to the respective measured-value channel "Lx".
Single-pole faults:
If, for example, voltage V
values, the device indicates pickups "Flx01 Pickup A" and "Flx01 Pickup C", because the undershooting was
detected in the first and third measured-value channel.
Two-pole faults:
If, for example, voltage V
pickup "Flx01 Pickup A", because the undershooting was detected in the first measured-value channel.
Table 2-23 Parameter in the Setting Dialog "Measurement Procedure", Mode of Operation 1-phase
Mode of Oper- Measured
ation Variable
Single-phase Current,
Voltage
Current
Voltage
P forward,
P reverse,
Q forward,
Q reverse
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
drops to such degree that the voltages V
A
drops to such degree that its threshold value is undershot, the device then indicates
AB
Parameter
MEAS. METHOD
Setting Options
Fundamental Harmonic Only the fundamental harmonic is evaluated, higher harmonics
are suppressed. This is the standard measurement procedure
of the protection functions.
True RMS The „True" RMS value is determined, i.e. higher harmonics are
evaluated. This procedure is applied, for example, if an over-
load protection element must be realized on the basis of a
current measurement, as the higher harmonics contribute to
thermal heating.
Parameter CURRENT
Setting Options
IA It is determined which current-measuring channel must be eval-
IB uated by the function. Depending on the device version, either
IC IN (normal-sensitive ground current input), INS (sensitive
IN ground current input) or IN2 (second ground current connected
INS to the device) can be selected.
IN2
Parameter VOLTAGE
Setting Options
VAB It is determined which voltage-measuring channel must be
VBC evaluated by the function. When selecting phase-to-phase volt-
VCA age, the threshold value must be set as a phase-to-phase
VAN value, when selecting a phase-to-ground variable as phase-to-
VBN ground voltage. The extent of the setting texts depends on the
VCN connection of the voltage transformer (see address 213 VT
VN Connect. 3ph).
Parameter POWER
Setting Options
IA VAN It is determined which power-measuring channel (current and
IB VBN voltage) must be evaluated by the function. With phase-to-
IC VCN phase voltage connections the parameter is hidden (see
address 213 VT Connect. 3ph).
2.17 Flexible Protection Functions
and V undershoot their threshold
AB CA
Notes
Functions
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