Setting Notes - Siemens SIPROTEC 4 User Manual

[sj6x-ueb-einph-kesselschut-020926-rei, 1, en_US]
Figure 2-45
2.5.4

Setting Notes

General
Single-phase time overcurrent protection can be set ON or OFF at address 2701 50 1Ph.
The settings are based on the particular application.
The setting ranges depend on whether the current measuring input is a sensitive or a normal input trans-
former (see also "Ordering Information" in the Appendix).
In case of a normal input transformer, set the pickup value for 50 1Ph-2 PICKUP in address 2702, the
pickup value for 50 1Ph-1 PICKUP in address 2705. If only one element is required, set the one not
required to ∞.
In case of a sensitive input transformer, set the pickup value for 50 1Ph-2 PICKUP in address 2703, the
pickup value for 50 1Ph-1 PICKUP in address 2706. If only one element is required, set the one not
required to ∞.
A trip time delay can be set in address 2704 50 1Ph-2 DELAY for the 50-2 element and for the 50-1 element
in address 2707 50 1Ph-1 DELAY. With setting 0 s no delay takes place.
The selected times are additional time delays and do not include the operating time (measuring time, etc.) of
the elements. The delay can also be set to ∞; the corresponding element will then not trip after pickup, but
the pickup is reported.
Special notes are given in the following for the use as high-impedance unit protection and tank leakage
protection.
Application as High-impedance Protection
The application as high-impedance protection requires that neutral point current detection is possible in the
system in addition to phase current detection (see example in
transformer must be available at device input Ι
current protection is set at the 7SJ62/64 device for the current at input Ι
The entire function of high-impedance protection is, however, dependent on the interaction of current trans-
former characteristics, external resistor R and voltage across R. The following section gives information on this
topic.
Current Transformer Data for High-impedance Protection
All current transformers must have an identical transformation ratio and nearly equal knee-point voltage. This
is usually the case if they are of equal design and identical rated data. The knee-point voltage can be approxi-
mately calculated from the rated data of a CT as follows:
SIPROTEC 4, 7SJ62/64, Manual
C53000-G1140-C207-8, Edition 08.2016
Principle of tank-leakage protection
Figure 2-44). Furthermore, a sensitive input
/Ι . In this case, only the pickup value for single-phase over-
N NS
/Ι
N
2.5 Single-Phase Overcurrent Protection
.
NS
Functions
121