ABB Relion REM601 - Setting Range of Earth Fault Overcurrent Protection; Negative-Sequence Overcurrent Protection; Functionality

Section 4 1MDU07212-YN Rev. D
Protection and Control Function
18 REF601 / REJ601 / REM601
Application Manual
4.2.3 Setting range of Earth fault Overcurrent Protection
Table 7: Setting ranges Non-directional earth fault protection, Low stage Io>, 51N
Description
Value
Nominal value of earth current
1 A or 5A for CT variant, 1A for sensor variant
Setting range of pick-up current Io>
External earth :
0.01...2.0 x In in steps 0.001, infinite
Internal earth :
0.1...2.0 x In in steps 0.001, infinite
Operate time delay (DT) to>
0.04...64 sec in steps of 0.01
Operating curve type (IDMT)
IEC 60255-3:
Normal inverse, Very inverse, Extremely inverse, Long-
time inverse
ANSI C37.112:
Moderate inverse, Normal Inverse, Very inverse,
Extremely inverse
Special curves:
RI inverse
Time multiplier setting ko (IDMT)
0.02...1.6, in steps of 0.01
Reset ratio
IDMT : 0.96 and DT : 0.98
Reset time
40 ms
Trig CBFP
Yes / No
Table 8: Setting ranges Non-directional earth fault protection, High stage Io>>, 50N
Description
Value
Setting range of pick-up current ‘Io>>’
External earth:
0.05...12.5 x In in steps 0.001, infinite
Internal earth:
0.5...12.5 x In in steps 0.001, infinite
Operation mode
Definite time
Operate time delay (DMT)
‘to >>’
0.04...64 sec in steps of 0.01
Reset ratio
0.98
Reset time
40 ms
Trig CBFP
Yes / No
4.3 Negative-sequence overcurrent protection
4.3.1 Functionality
The negative-sequence overcurrent protection is used for increasing sensitivity to
detect unbalance load or unsymmetrical feeder voltages.
The operate time characteristics is based on definite time (DT) i.e. function operates
after a predefined operate time and resets when the fault current disappears.