17. Protection functions
Table 20. Low-set phase overcurrent protection, stage I> / 51
Parameter
Value (Range)
Setting range of pick-up current ‘I >’ 0.2...1.0 x In in steps 0.025, innite
Operation accuracy ± 5.0% of set value
Operate time delay (DMT) ‘t >’ 0.1...1.6 sec in steps of 0.1 for B=1
0.5...8.0 sec in steps of 0.5 for B=5
Operation time accuracy ± 5.0% of set value or ± 30 msec
Operating curve type
Normal inverse, Very inverse, Extremely inverse, Long-time inverse
IEC 60255-3:
Special curves:
RI inverse
Time multiplier setting ‘k’ 0.1...1.6, in steps of 0.1
Operation time accuracy
class E(5) or ± 30 msec
± 5.0% of set value or ± 30 msec
IEC characteristics
RI characteristics
Reset ratio IDMT : 0.96 and DT : 0.98
Table 21. High-set phase overcurrent protection, stage I>> / 50-1
Parameter
Value (Range)
Setting range of pick-up current ‘I >>’ 1.0...2.75 x In in steps 0.25, innite
Operation accuracy ± 5.0% of set value
Operation mode Denite time
Operation time accuracy ± 5.0% of set value or ± 30 msec
Reset ratio 0.98
Operate time delay (DMT) ‘t >>’ 0.1...0.45 sec in steps of 0.05
Table 22. Very High-set phase overcurrent protection, stage I>>> / 50-2
Parameter
Value (Range)
Setting range of pick-up current ‘I >>>’ 2.0...15.0 x In in steps 1.0, innite
Operation accuracy ± 5.0% of set value
Operation mode Instantaneous
Operation time accuracy ± 15 msec
Reset ratio 0.98
Operate time ‘t >>>’ 0.05 sec