Siemens 7SR12 Argus User Manual

7SR11 & 7SR12 Description Of Operation
Chapter 1 Page 40 of 88 ©2017 Siemens Protection Devices Limited
3.3.2 INSTANTANEOUS MEASURED EARTH FAULT PROTECTION (50G)
Two instantaneous derived earth fault elements are provided in the 7SR11 relay and four elements are provided
in the 7SR12 relay.
50G-1, 50G-2, (50G-3 & 50G-4 – 7SR12)
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 A binary or virtual input.
79 E/F Inst Trips: 50G-n When ‘delayed’ trips only are allowed in the auto-reclose sequence
(79 E/F Prot’n Trip n = Delayed).
50-n Inrush Action: Block Operation of the inrush current detector function.
50G-n VTSAction: Inhibit Operation of the VT Supervision function (7SR1205 & 7SR1206).
50G-n
>
c
50G-n Setting
Forward
Reverse
50G-n Dir.
Control
Non-Dir
≥1
&
&
50G-
n Dir En
67G Fwd
67G Rev
50G-n Delay
50G-n VTS Action
Off
Non Dir
Inhibit
VT Fail
& &
&
≥1
IG
51G/50G Measurement
General Pickup
Inhibit 50G-n
&
50G
-n Element
Enabled
Disabled
81
HBL2
50
G-n Inrush
Action
Off
Inhibit
&
50G-n Dir En
&
79 P/F Inst Trips
= 50
G-n
79 P/F Prot’n Trip n
= Delayed
AUTORECLOSE
Figure 3-9 Logic Diagram: Measured Instantaneous Earth-fault Element

Siemens 7SR12 Argus Specifications

General

Brand	Siemens
Model	7SR12 Argus
Category	Protection Device
Language	English