Siemens siprotec SJ62 User Manual page 111

2 Functions
109
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 the following Table, along with the
matching times. Deviating values I/I
cated.
Current flows less than the smallest current value entered will not lead to an exten-
sion of the tripping time. The pickup curve (see Figure 2-13, 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 reduc-
tion of the tripping time. The pickup characteristic (see Figure 2-13, right side) goes
parallel to the current axis, beginning with the greatest current point.
Table 2-8 Preferential values of standardized currents for user-defined tripping curves
I/Ip = 1 to 1.94
1.00 1.50 2.00
1.06 1.56 2.25
1.13 1.63 2.50
1.19 1.69 2.75
1.25 1.75 3.00
1.31 1.81 3.25
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 2-8, 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 pro-
longation of the reset time. The reset curve (see Figure 2-13, 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 2-13, left side) is parallel
to the current axis, beginning with the smallest current point.
are rounded. This, however, will not be indi-
p
I/Ip = 2 to 4.75 I/Ip = 5 to 7.75
3.50 5.00
3.75 5.25
4.00 5.50
4.25 5.75
4.50 6.00
4.75 6.25
I/Ip = 8 to 20
6.50 8.00 15.00
6.75 9.00 16.00
7.00 10.00 17.00
7.25 11.00 18.00
7.50 12.00 19.00
7.75 13.00 20.00
14.00
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015