Table Of Contents; Contents - Siemens 7SR21 Manual

Contents

Document Release History....................................................................................................................1
Software Revision History.....................................................................................................................1
Contents ..................................................................................................................................................2
Section 1: Common Functions .............................................................................................................5
1.1 Overview ...................................................................................................................................5
1.2 Before Testing...........................................................................................................................5
1.2.1 Safety ...........................................................................................................................5
1.2.2 Sequence of Tests .......................................................................................................5
1.2.3 Test Equipment ............................................................................................................6
1.2.4 Precautions ..................................................................................................................6
1.2.5 Applying Settings .........................................................................................................6
1.3 Tests .........................................................................................................................................8
1.3.1 Inspection .....................................................................................................................8
1.3.2 Secondary Injection Tests............................................................................................8
1.3.3 Primary Injection Tests.................................................................................................8
1.3.4 Putting into Service ......................................................................................................8
1.4 AC Energising Quantities..........................................................................................................9
1.5 Binary Inputs ...........................................................................................................................10
1.6 Binary Outputs ........................................................................................................................11
1.7 Relay Case Shorting Contacts................................................................................................12
Section 2: Protection Functions .........................................................................................................13
2.1 Phase Directional Polarity Check............................................................................................14
2.1.1 2 out of 3 logic............................................................................................................15
2.2 Phase Overcurrent (67/50,67/51) ...........................................................................................16
2.2.1 Definite Time Overcurrent
2.2.2 Inverse Time Overcurrent (51) .................................................................................17
2.3 Voltage Controlled Overcurrent (51V) ....................................................................................19
2.4 Cold Load (51C)......................................................................................................................21
2.4.1 Inverse Time Overcurrent (51C) ..............................................................................22
2.5 Directional Earth Fault Polarity Check (67N) ..........................................................................24
2.6 Derived Earth Fault (67/50N, 67/51N) ....................................................................................25
2.6.1 Directional Polarity .....................................................................................................26
2.6.2 Definite Time Overcurrent
2.6.3 Inverse Time Overcurrent (51N) ..............................................................................26
2.7 Measured Earth fault (67/50G,67/51G) ..................................................................................29
2.7.1 Directional Polarity .....................................................................................................30
2.7.2 Definite Time Overcurrent
2.7.3 Inverse Time Overcurrent (67/51G) .........................................................................30
2.8 Sensitive Earth fault (67/50S,67/51S).....................................................................................33
2.8.1 Directional Polarity .....................................................................................................34
2.8.2 Definite Time Overcurrent
2.8.3 Inverse Time Overcurrent (51SEF)..........................................................................34
2.9 Restricted Earth fault (64H) ..................................................................................................37
2.10 Negative Phase Sequence Overcurrent (46NPS) ..................................................................39
2.10.1 Definite Time NPS Overcurrent
2.10.2 Inverse Time NPS Overcurrent (46IT) .....................................................................40
2.11 Undercurrent (37)..................................................................................................................42
©2010 Siemens Protection Devices Limited
7SR21 & 7SR22 Argus Commissioning and Maintenance
(50) ...............................................................................17
(50N).............................................................................26
(67/50G)........................................................................30
(50SEF) ........................................................................34
(46DT) ..................................................................40
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