Siemens siprotec SJ62 User Manual page 110

67N-TOC Direction-
al Element with IEC
or ANSI Curves
(ground)
User-defined
characteristic (In-
verse Time Phases
and ground)
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
Having set address 116 67N/67N-TOC = TOC IEC when configuring the protective
functions (Section 2.1.1), the parameters for the inverse characteristics will also be
available. Specify in address 1611 67N-TOC IEC the desired IEC characteristic
(Normal Inverse, Very Inverse, Extremely Inv. or Long Inverse). If
address 116 67N/67N-TOC = TOC ANSI, you can specify the desired ANSI–
characteristic (Very Inverse, Inverse, Short Inverse, Long Inverse,
Moderately Inv., Extremely Inv. or Definite Inv.) in address 1612 67N-
TOC ANSI.
If the relay is used to protect transformers or motors with large inrush currents, the
inrush restraint feature of 7SJ62/63/64 may be used for the 67N-TOC relay element
(for more information see margin heading "Inrush Restraint").
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
67N-TOC PICKUP. This means that a pickup will only occur if a current of about 1.1
times the setting value is present. If Disk Emulation was selected at address 1610
67N-TOC DropOut, reset will occur in accordance with the reset curve as for the ex-
isting non-directional time overcurrent protection described in Section 2.2.
The current value is set at address 1607 67N-TOC PICKUP. The minimum appearing
ground fault current is most relevant for this setting.
The corresponding element time multiplication factor for an IEC characteristic is set at
address 1608 67N-TOC T-DIAL and in address 1609 67N-TOC T-DIAL for an
ANSI characteristic. This has to be coordinated with the system grading coordination
chart for directional tripping. For ground currents with grounded network, you can
mostly set up a separate grading coordination chart with shorter delay times.
The time multiplier can also be set to ∞. After pickup the element will then not trip.
Pickup, however, will be signaled. If the 67N-TOC element is not required at all,
address 116 67N/67N-TOC should be set to Definite Time during protective func-
tion configuration (see Section 2.1.1).
If address 115 or 116 were set to User Defined PU or User def. Reset during
configuration of the user-defined characteristic option, a maximum of 20 value pairs
(current and time) may be entered at address 1530 67 or 1630 M.of PU
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 param-
eter 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 nec-
essary.
The default setting of current values is ∞. They are, therefore, not enabled — and no
pickup or tripping of these protective functions will occur.
2.3 Directional Overcurrent Protection 67, 67N
TD.
108