Siemens 7SR224 - Page 302

7SR224 Argus Applications
©2010 Siemens Protection Devices Limited Chapter 7 Page 3 of 50
4.4.4 Auto-Changeover Scheme Example....................................................................................... 43
Section 5: Supervision Functions........................................................................................................................... 44
5.1 Circuit-Breaker Fail (50BF) ................................................................................................................... 44
5.1.1 Settings Guidelines ................................................................................................................. 44
5.2 Current Transformer Supervision (60CTS) ........................................................................................... 46
5.3 Voltage Transformer Supervision (60VTS) ........................................................................................... 47
5.4 Trip-Circuit Supervision (74TCS) .......................................................................................................... 48
5.4.1 Trip Circuit Supervision Connections ...................................................................................... 48
5.5 Inrush Detector (81HBL2) ..................................................................................................................... 50
5.6 Broken Conductor / Load Imbalance (46BC) ........................................................................................ 50
5.7 Circuit-Breaker Maintenance................................................................................................................. 50
List of Figures
Figure 1.1-1 Example Use of Alternative Settings Groups ......................................................................4
Figure 1.2-1 Example of External Device Alarm and Trip Wiring.............................................................5
Figure 1.2-2 – Binary Input Configurations Providing Compliance with EATS 48-4 Classes
ESI 1 and ESI 2 ...................................................................................................................7
Figure 2.1-1 IEC NI Curve with Time Multiplier and Follower DTL Applied .............................................9
Figure 2.1-2 IEC NI Curve with Minimum Operate Time Setting Applied ..............................................10
Figure 2.4-1 General Form of DTL Operate Characteristic....................................................................13
Figure 2.4-2 Blocking Scheme Using Instantaneous Overcurrent Elements .........................................14
Figure 2.5-1 Sensitive Earth Fault Protection Application......................................................................15
Figure 2.6-1 Directional Characteristics ................................................................................................16
Figure 2.6-2 Phase Fault Angles............................................................................................................16
Figure 2.6-3 Application of Directional Overcurrent Protection..............................................................17
Figure 2.6-4 Feeder Fault on Interconnected Network ..........................................................................18
Figure 2.7-1 Earth Fault Angles .............................................................................................................19
Figure 2.8-1 Balanced and Restricted Earth-fault protection of Transformers ....................................20
Figure 2.8-2 Composite Overcurrent and Restricted Earth-fault Protection .........................................21
Figure 2.11-1 Thermal Overload Heating and Cooling Characteristic .............................................22
Figure 2.13-1 NVD Application...............................................................................................................24
Figure 2.13-2 NVD Protection Connections ...........................................................................................24
Figure 2.15-1 Load Shedding Scheme Using Under-Frequency Elements...........................................26
Figure 4.1-1 Sequence Co-ordination ....................................................................................................29
Figure 4.3-1 Sysyem Diagram showing Normally Open (TIE) Point......................................................36
Figure 4.3-2 Typical System Interconnections showing Normally Open (TIE) Points and
LOV Action Delay timer grading margins. .........................................................................39
Figure 4.4-1 System Diagram showing application of Single/Triple pole Reclosers..............................40
Figure 4.4-2 Example Use of Quick Logic..............................................................................................43
Figure 5.1-1 - Circuit Breaker Fail ..........................................................................................................44
Figure 5.1-2 - Single Stage Circuit Breaker Fail Timing.........................................................................45
Figure 5.1-3 - Two Stage Circuit Breaker Fail Timing............................................................................45
Figure 5.4-1:Trip Circuit Supervision Scheme 1 (H5) ............................................................................48
Figure 5.4-2:Trip Circuit Supervision Scheme 2 (H6) ............................................................................49
Figure 5.4-3:Trip Circuit Supervision Scheme 3 (H7) ............................................................................49
List of Tables
Table 2-1 Application of IDMTL Characteristics.................................................................................11
Table 4-1 Typical Check Synchronising Settings...............................................................................34
Table 4-2 Typical System Synchronising Settings.............................................................................35
Table 5-1 Determination of VT Failure (1 or 2 Phases) .....................................................................46
Table 5-2 Determination of VT Failure (1 or 2 Phases) .....................................................................47
Table 5-3 Determination of VT Failure (3 Phases) ............................................................................47
Table 5-4 Magnetic Inrush Bias .........................................................................................................50