Instantaneous Measured Earth Fault Protection (50G); Figure 3.4.2-1 Logic Diagram: Measured Instantaneous Earth-Fault Element - Siemens Argus 7SR21 Technical Manual

7SR210 & 7SR220 Description of Operation
3.4.2

Instantaneous Measured Earth Fault Protection (50G)

Two instantaneous measured earth fault elements are provided in the 7SR21 relay. Four elements are provided in
the 7SR22 relay 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 50G-n Setting and a follower time
delay 50G-n Delay. The instantaneous elements have transient free operation.
Where directional elements are present the direction of operation can be set using 50G-n Dir. Control setting.
Directional logic is provided independently for each 50G-n element.
Operation of the instantaneous measured earth fault elements can be inhibited from: -
Inhibit 50G-n
79 E/F Inst Trips: 50G-n
50G-n Inrush Action: Inhibit
50G-n VTSAction: Inhibit
Figure 3.4.2-1
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A binary or virtual input, function key or remote data Comms.
When 'delayed' trips only are allowed in the auto-reclose sequence
(79 E/F Prot'n Trip n = Delayed).
Operation of the current inrush detector function.
Operation of the VT Supervision function (7SR22).
Logic Diagram: Measured Instantaneous Earth-fault Element
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