ABB Relion 670 Series Technical Reference Manual page 427

1MRK505222-UUS C
7.5
7.5.1
Technical reference manual
Function
Imaginary part of source Z used
for current polarization
Operate time, pickup function
Reset time, pickup function
Critical impulse time
Impulse margin time
Four step directional negative phase sequence
overcurrent protection NS4PTOC (46I2)
Function description
Four step negative sequence
overcurrent protection
Introduction
Four step negative sequence overcurrent protection (NS4PTOC, (4612) ) has an inverse
or definite time delay independent for each step separately.
All IEC and ANSI time delayed characteristics are available together with an optional
user defined characteristic.
The directional function is voltage polarized or dual polarized.
NS4PTOC (4612) can be set directional or non-directional independently for each of
the steps.
NS4PTOC (4612) can be used as main protection for unsymmetrical fault; phase-phase
short circuits, phase-phase-ground short circuits and single phase ground faults.
NS4PTOC (4612) can also be used to provide a system back-up for example, in the
case of the primary protection being out of service due to communication or voltage
transformer circuit failure.
Directional operation can be combined together with corresponding communication
logic in permissive or blocking teleprotection scheme. The same logic as for
Range or value
(0.50–3000.00) W/phase
25 ms typically at 0 to 2 x I
set
25 ms typically at 2 to 0 x I
set
10 ms typically at 0 to 2 x I
set
15 ms typically
IEC 61850 IEC 60617 identification ANSI/IEEE C37.2
identification
NS4PTOC
4
4
IEC10000053 V1 EN
Section 7
Current protection
Accuracy
-
-
-
-
-
device number
46I2
I2
alt
421