Siemens 7SC80 Manual page 131

For example, for the element 67N-TOC-1 you can select:
At Address 1648 67N-TOC-1 IEC the desired IEC–characteristic.
At Address 1668 67N-TOC-1 ANSI the desired ANSI–characteristic
At Address 1669 67N-TOC-1 Rec. the desired Recloser–characteristic
The possible settings for the curves are described in the sections above. If curve type is not selected correctly,
a warning message for this element would be announced.
If the inverse time trip characteristic is selected, it must be noted that a safety factor of about 1.1 has already
been included between the pickup value and the setting value. This means that a pickup will only occur if a
current of about 1.1 times the setting value is present. If Disk Emulation were selected at address 1647
67N-TOC-1 Drop. or 1653 67N-TOC-2 Drop. or 1659 67N-TOC-3 Drop. or 1665 67N-TOC-4 Drop.,
resets will occur in accordance with the reset curves as described before. Recloser curves don't support disk
emulation.
The current values are set in address 1644 67N-TOC-1 PU, address 1650 67N-TOC-2 PU, address 1656
67N-TOC-3 PU and address 1662 67N-TOC-4 PU. These pickup values could be set to ∞ individually. If an
inverse element's pickup value is set to ∞, this element is disabled. The setting is mainly determined by the
maximum anticipated operating current. Pickup due to overload should never occur since in this mode, the
device operates as fault protection with correspondingly short tripping times and not as overload protection.
The corresponding time multipliers are set at address 1645 67N-TOC-1 TD, address 1651 67N-TOC-2 TD,
address 1657 67N-TOC-3 TD or address 1663 67N-TOC-4 TD. They must be coordinated with the time
coordination chart of the system.
User-defined characteristic (Inverse Time Phases and ground)
If address 115 or 116 were set to User Defined PU or User def. Reset during configuration of the
userdefined characteristic option, a maximum of 20 value pairs (current and time) may be entered at address
1530 67 or 1630 M.of PU TD. This option allows point-by-point entry of any desired curve.
If address 115 or 116 were set to User def. Reset during configuration, additional value pairs (current
and reset time) may be entered in address 1531 MofPU Res T/Tp or 1631 I/IEp Rf T/TEp to represent
the reset curve.
Entry of the value pair (current and time) is a multiple of the settings of the values of the addresses 1507 67-
TOC PICKUP or 1607 67N-TOC PICKUP and 1508 67 TIME DIAL or 1608 67N-TOC T-DIAL. Therefore,
it is recommended that parameter values are initially set to 1.00 for simplicity. Once the curve is entered, the
settings at addresses 1507 and 1607 or/and 1508 and 1608 may be modified later on if necessary.
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. Devi-
ating 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
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
with the greatest current point.
Table 2-9
MofPU = 1 bis 1.94
1.00 1.50
1.06 1.56
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017
Figure 2-19, right side) goes parallel to the current axis, up to the smallest
Figure
Preferential values of standardized currents for user-defined tripping curves
MofPU = 2 bis 4.75
2.00 3.50
2.25 3.75
2.3 Directional Overcurrent Protection 67, 67N
2-19, right side) goes parallel to the current axis, beginning
MofPU = 5 bis 7.75
5.00 6.50
5.25 6.75
Functions
MofPU = 8 bis 20
8.00 15.00
9.00 16.00
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