Siemens SIPROTEC 7SJ62 Manual page 115

The default setting of current values is ∞. They are, therefore, not enabled — and no pickup or tripping of these
protective functions will occur.
The following must be observed:
• The value pairs should be entered in increasing sequence. If desired, fewer than 20 pairs may be entered.
In most cases, about 10 pairs is sufficient to define the characteristic accurately. A value pair which will not
be used has to be made invalid entering „∞" for the threshold! The user must ensure the value pairs produce
a clear and constant characteristic.
The current values entered should be those from following Table, along with the matching times. Deviating
values MofPU (multiples of PU value) are rounded. This, however, will not be indicated.
Current flows less than the smallest current value entered will not lead to an extension of the tripping time.
The pickup curve (see Figure 2-17, right side) goes parallel to the current axis, up to the smallest current
point.
Current flows greater than the highest current value entered will not lead to a reduction of the tripping time.
The pickup characteristic (see Figure 2-17, right side) goes parallel to the current axis, beginning with the
greatest current point.
Table 2-9
MofPU = 1 to 1.94
1,00 1,50
1,06 1,56
1,13 1,63
1,19 1,69
1,25 1,75
1,31 1,81
1,38 1,88
1,44 1,94
The value pairs are entered at address 1531 MofPU Res T/Tp to recreate the reset curve. The following must
be observed:
• The current values entered should be those from Table 2-9, along with the matching times. Deviating values
I/Ip are rounded. This, however, will not be indicated.
Current flows greater than the highest current value entered will not lead to a prolongation of the reset time.
The reset curve (see Figure 2-17, left side) is parallel to the current axis, beginning with the largest current
point.
Current flows which are less than the smallest current value entered will not lead to a reduction of the reset
time. The reset curve (see Figure 2-17, left side) is parallel to the current axis, beginning with the smallest
current point.
Table 2-10
MofPU = 1 to 0.86
1,00 0,93
0,99 0,92
0,98 0,91
0,97 0,90
0,96 0,89
0.95 0,88
0,94 0,86
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
Preferential values of standardized currents for user-defined tripping curves
MofPU = 2 to 4.75
2,00 3,50
2,25 3,75
2,50 4,00
2,75 4,25
3,00 4,50
3,25 4,75
Preferential values of standardized currents for user-defined dropout curves
MofPU = 0.84 to 0.67
0,84 0,75
0,83 0,73
0,81 0,72
0,80 0,70
0,78 0,69
0,77 0,67
2.3 Directional Overcurrent Protection 67, 67N
MofPU = 5 to 7.75
5,00 6,50
5,25 6,75
5,50 7,00
5,75 7,25
6,00 7,50
6,25 7,75
MofPU = 0.66 to 0.38
0,66 0,53
0,64 0,50
0,63 0,47
0,61 0,44
0,59 0,41
0,56 0,38
Functions
MofPU = 8 to 20
8,00 15,00
9,00 16,00
10,00 17,00
11,00 18,00
12,00 19,00
13,00 20,00
14,00
MofPU = 0.34 to 0.00
0,34 0,16
0,31 0,13
0,28 0,09
0,25 0,06
022 0,03
0,19 0,00
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