Instantaneous Measured Earth Fault Protection (50G); Figure 3-9 Logic Diagram: Measured Instantaneous Earth-Fault Element - Siemens 7SR10 Argus Series Manual

3.3.2

Instantaneous Measured Earth Fault Protection (50G)

Two instantaneous measured earth fault elements are provided in the 7SR1002/7SR1003 relay and four elements
are provided in the 7SR1004 relay.
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 e.g. giving the option of using two elements
set to forward and two to reverse.
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: Block
50G-n VTSAction: Inhibit
50G-n Inrush
Action
Off
Inhibit
&
81HBL2
AUTORECLOSE
79 P/F Inst Trips
= 50G-n
&
79 P/F Prot'n Trip n
= Delayed
50G-n Dir.
Control
Non-Dir
Forward
Reverse
67G Fwd
67G Rev
Figure 3-9
©2018 Siemens Protection Devices Limited
50G-1, 50G-2, (50G-3 & 50G-4 – 7SR1004)
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.
50G-n Element
Disabled
Enabled
&
Inhibit 50G-n
50G-n Dir En
51G/50G Measurement
IL4 (I )
G
&
&
Logic Diagram: Measured Instantaneous Earth-fault Element
50G-n Setting
c
>
50G-n VTS Action
Off
Non Dir
Inhibit
&
VT Fail
≥1 &
7SR10 Description of Operation
General Pickup
50G-n Delay
50G-n
&
≥1
50G-n Dir En
Chapter 1 Page 35 of 77