increased by means of a parallel resistor in a compensation coil. In networks where the
neutral point is grounded through a low resistance, the characteristic angle is always 0º.
As the amplitude of the residual current is independent of the fault location, the selectivity
of the ground-fault protection is achieved with time coordination.
The use of wattmetric protection gives a possibility to use the dedicated inverse definite
minimum time characteristics. This is applicable in large high-impedance grounded
networks with a large capacitive ground-fault current.
In a network employing a low-impedance grounded system, a medium-size neutral point
resistor is used. Such a resistor gives a resistive ground-fault current component of about
200...400 A for an excessive ground fault. In such a system, the directional residual power
protection gives better possibilities for selectivity enabled by the inverse time power
characteristics.
4.2.6.8 Signals
Table 399: 32N Input signals
Name Type Default Description
IG SIGNAL 0 Residual current
VG SIGNAL 0 Residual voltage
BLOCK BOOLEAN 0=False Block signal for activating the blocking mode
RCA_CTL BOOLEAN 0=False Relay characteristic angle control
Table 400: 32N Output signals
Name
Type Description
TRIP BOOLEAN Trip
PICKUP BOOLEAN Pickup
4.2.6.9 Settings
Table 401: 32N Group settings (Basic)
Parameter
Values (Range) Unit Step Default Description
Directional mode 2=Forward
3=Reverse
2=Forward Directional mode
Current pickup value 0.010...5.000 xIn 0.001 0.010 Minimum trip residual current for deciding fault
direction
Voltage pickup value 0.010...1.000 xUn 0.001 0.010 Pickup value for residual voltage
Power pickup value 0.003...1.000 xPn 0.001 0.003 Pickup value for residual active power
Table continues on next page
1MAC059074-MB A Section 4
Protection functions
615 series ANSI 421
Technical Manual
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