Instantaneous Overcurrent Protection (50); Figure 3.1-2 Logic Diagram: Instantaneous Over-Current Element - Siemens 7SR224 Technical Manual

3.1.2 Instantaneous Overcurrent Protection (50)

Four elements are provided e.g. giving the option of using two elements set to forward and two to reverse.
Each instantaneous element (50-n) has independent settings. 50-n Setting for pick-up current and 50-n Delay
follower time delay. The instantaneous elements have transient free operation.
For the directional elements the direction of operation can be set using 50-n Dir. Control setting. Directional logic
is provided independently for each 50-n element.
Operation of the instantaneous overcurrent elements can be inhibited from:
Inhibit 50-n
79 P/F Inst Trips: 50-n
50-n Inrush Action: Inhibit
50-n VTS Action: Inhibit Operation of the VT Supervision function.

Figure 3.1-2 Logic Diagram: Instantaneous Over-current Element

©2010 Siemens Protection Devices Limited
A binary or virtual input, or function key.
When 'delayed' trips only are allowed in the autoreclose sequence
(79 P/F Prot'n Trip n = Delayed).
Operation of the inrush current detector function.
7SR224 Argus Description of Operation
Chapter 1 Page 19 of 70