Name Values (Range) Unit Step Default Description
tResetDef2 0.000 - 60.000 s 0.001 0.000 Time delay for reset of definite timer of
step 2, in sec
K2 1.0 - 99.0 s 0.1 10.0 Neg. seq. capability value of generator for
step 2, in sec
t2Min 0.000 - 60.000 s 0.001 5.000 Minimum operate time for inverse curves
for step 2
t2Max 0.00 - 6000.00 s 0.01 1000.00 Maximum trip delay for step 2, in sec
ResetMultip2 0.01 - 20.00 - 0.01 1.00 Reset multiplier for K2, defines reset time
of inverse curve
Table 302: NS2PTOC (46I2) Non group settings (basic)
Name Values (Range) Unit Step Default Description
GlobalBaseSel 1 - 12 - 1 1 Selection of one of the Global Base Value
groups
8.14.6 Monitored data
PID-3854-MONITOREDDATA v4
Table 303: NS2PTOC (46I2) Monitored data
Name Type Values (Range) Unit Description
NSCURR REAL - A Negative sequence current in primary
amps
8.14.7 Operation principle
GUID-0DEE12AC-2CA3-4E10-8DD0-888000BD898A v4
The negative sequence time overcurrent protection for machines (NS2PTOC, 46I2) function
directly measures the amplitude of the negative phase sequence component of the measured
current. NS2PTOC (46I2) sets the PICKUP, PU_ST1 or PU_ST2 outputs active and starts to count
trip time only when the measured negative sequence current value rises above the set value of
parameters
I2-1>
or
I2-2>
respectively.
To avoid oscillation in the output signals, a certain hysteresis has been included. For both steps,
the reset ratio is 0.97.
Step 1 of NS2PTOC (46I2) can operate in the Definite Time (DT) or Inverse Time (IDMT) mode
depending on the selected value for the
CurveType1
parameter. If
CurveType
1=
Definite
, NS2PTOC
(46I2) operates with a Definite Time Delay characteristic and if
CurveType
1 =
Inverse
, NS2PTOC
(46I2) operates with an Inverse Time Delay characteristic. Step 2 is operating in an analogous way
as Step 1.
Definite time delay is not dependent on the magnitude of measured negative sequence current.
Once the measured negative sequence current exceeds the set level, the settable definite timer
t1
or
t2
respectively, starts to count and the corresponding trip signal gets activated after the pre-
set definite time delay has elapsed. Reset time in definite time mode is determined by the setting
parameters
tResetDef1
or
tResetDef2
respectively. If NS2PTOC (46I2) has already picked up but
not tripped and measured negative sequence current goes below the pickup value, the pickup
outputs remains active for the time defined by the resetting parameters.
Section 8 1MRK 502 066-UUS B
Current protection
564
Technical manual
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