Inverse Time Overcurrent Elements 51, 51N - Siemens 7SC80 Manual

Functions
2.2 Overcurrent Protection 50, 51, 50N, 51N
[7sj6x-ueberstromst-ie-20061212, 1, en_US]
Figure 2-9
If parameter 1313 MANUAL CLOSE is set to 50N-1 instant. and manual close detection is used, a pickup
causes instantaneous tripping even if the element is blocked via a binary input.
The same applies to 79 AR 50N-1 inst.
The dropout delay only operates when no inrush was detected. An incoming inrush resets an already running
dropout time delay.
[7sj6x_rueckfallverzoegerung_i_gr_erde_260803_he, 1, en_US]
Figure 2-10

Inverse Time Overcurrent Elements 51, 51N

2.2.4
The inverse time overcurrent elements depend on the order variant. They always operate with an inverse time
characteristic according to IEC or ANSI standards, a user-defined characteristic, or a recloser characteristic. The
characteristic curves and associated formulas are shown in the Technical Data.
74
Logic diagram for the 50N-1 overcurrent current element
Logic of the dropout delay for 50N-1
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017