7SR210 & 7SR220 Description of Operation
Unrestricted ©2018 Siemens Protection Devices Limited
Page 27 of 94
3.1.2
Instantaneous Overcurrent Protection (50)
Two instantaneous overcurrent elements are provided in the 7SR21 relay. Four elements are provided in the
7SR22 e.g. giving the option of using two elements set to forward and two to reverse.
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.
Operation of the instantaneous overcurrent elements can be inhibited from:
Inhibit 50-n
A binary input, virtual input, function key or remote data Comms.
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:
Inhibit
Operation of the inrush current detector function.
50-n VTS Action:
Inhibit
Operation of the VT Supervision function (7SR22).
Figure 3.1.2-1
Logic Diagram: Instantaneous Over-current Element
Summary of Contents for Argus 7SR21
Page 1: ...Energy Management 7SR21 7SR22 Argus Overcurrent Relay Reyrolle Protection Devices ...
Page 2: ......
Page 4: ...Contents 7SR11 and 7SR12 Page 2 of 2 2018 Siemens Protection Devices Limited ...
Page 185: ...7SR210 Settings Guide Unrestricted 2018 Siemens Protection Devices Limited Page 61 of 61 ...
Page 277: ...7SR220 Settings Guide Unrestricted Page 72 of 107 2013 Siemens Protection Devices Limited ...
Page 382: ...7SR220 Technical Manual Chapter 4 Page 2 of 96 2017 Siemens Protection Devices Limited ...
Page 386: ...7SR220 Technical Manual Chapter 4 Page 6 of 96 2017 Siemens Protection Devices Limited ...
Page 398: ...7SR220 Technical Manual Chapter 4 Page 18 of 96 2017 Siemens Protection Devices Limited ...
Page 414: ...7SR220 Technical Manual Chapter 4 Page 34 of 96 2017 Siemens Protection Devices Limited ...
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