Siemens 7SR12 Argus User Manual

7SR11 & 7SR12 Description Of Operation
Chapter 1 Page 32 of 88 ©2017 Siemens Protection Devices Limited
V
23
I
L1
V
31
2
-out-of-3
logic
(fwd)
V
12
I
L3
I
L2
fwd
rev
fwd
rev
fwd
rev
2
-out
-
of-
3
logic
(
rev)
67
2
-
Out-Of-3 Logic
67
Min. Voltage
67
Charact
. Angle
L1 Fwd
L1
Rev
L3 Fwd
L2 Fwd
L3 Rev
L2
Rev
Directional
Control Signal
Figure 3-1 Logic Diagram: Directional Overcurrent Element (67)
3.1.2 INSTANTANEOUS OVERCURRENT PROTECTION (50)
Two Instantaneous overcurrent elements are provided in the 7SR11 relay and four elements are provided in the
7SR12 relay.
50-1, 50-2, (50-3 & 50-4 – 7SR12)
Each instantaneous element (50-n) has independent settings. 50-n Setting for pick-up current and 50-n Delay
follower time delay. The instantaneous elements have transient free operation.
Where directional elements are present the direction of operation can be set using 50-n Dir. Control setting.
Directional logic is provided independently for each 50-n element, e.g. giving the option of using two elements set
to forward and two to reverse.
Operation of the instantaneous overcurrent elements can be inhibited from:
Inhibit 50-n A binary or virtual input.
79 P/F Inst Trips: 50-n When ‘delayed’ trips only are allowed in the auto-reclose sequence
(79 P/F Prot’n Trip n = Delayed).
50-n Inrush Action: Block Operation of the inrush current detector function.
50-n VTS Action: Inhibit Operation of the VT Supervision function (7SR1205 & 7SR1206).

Siemens 7SR12 Argus Specifications

General

Brand	Siemens
Model	7SR12 Argus
Category	Protection Device
Language	English