Instantaneous Measured Earth Fault Protection (50G); Figure 3.5.2-1 Logic Diagram: Measured Instantaneous Earth-Fault Element - Siemens 7SR18 Solkor Manual

7SR18 Description Of Operation
3.5.2

Instantaneous Measured Earth Fault Protection (50G)

Up to four instantaneous derived earth fault elements are provided in the relay (depending upon variant): -
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.
Operation of the instantaneous measured earth fault elements can be inhibited from:
Inhibit 50G-n
79 E/F Inst Trips: 51N-n
50-n Inrush Action: Block
50G-n VTSAction: Inhibit

Figure 3.5.2-1 Logic Diagram: Measured Instantaneous Earth-fault Element

Unrestricted Page 42 of 78
50G-1, 50G-2, 50G-3 & 50G-4
A binary or virtual input.
When 'delayed' trips only are allowed in the auto-reclose sequence
(79 E/F Prot'n Trip n = Delayed).
Operation of the inrush current detector function.
Operation of the VT Supervision function
©2018 Siemens Protection Devices Limited