Instantaneous Sensitive Earth Fault Protection (50Sef); Figure 3.4-2 Logic Diagram: Sef Instantaneous Element - Siemens 7SR224 Technical Manual

3.4.2 Instantaneous Sensitive Earth Fault Protection (50SEF)

Four elements are provided e.g. giving the option of using two elements set to forward and two to reverse.
Each instantaneous element has independent settings for pick-up current 50SEF-n Setting and a follower time
delay 50SEF-n Delay. The instantaneous elements have transient free operation.
For the directional elements the direction of operation can be set using 50SEF-n Dir. Control setting. Directional
logic is provided independently for each 50SEF-n element.
Operation of the instantaneous earth fault elements can be inhibited from:
Inhibit 50SEF-n
79 SEF Inst Trips: 50SEF-n
50SEF-n VTSAction: Inhibit

Figure 3.4-2 Logic Diagram: SEF Instantaneous Element

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A binary or virtual input, or function key
When 'delayed' trips only are allowed in the autoreclose sequence
(79 SEF Prot'n Trip n = Delayed).
Operation of the VT Supervision function.
7SR224 Argus Description of Operation
Chapter 1 Page 27 of 70