Siemens 7SR224 - Page 4

7SR224 Argus Commissioning & Maintenance Guide
©2010 Siemens Protection Devices Limited Chapter 6 Page 4 of 73
List of Figures
Figure 2-1 Directional Phase Fault Boundary System Angles ............................................................15
Figure 2-2 Phase Overcurrent.............................................................................................................16
Figure 2-3 Voltage Controlled Overcurrent .........................................................................................19
Figure 2-4 Cold Load...........................................................................................................................21
Figure 2-5 Cold Load Logic diagram...................................................................................................22
Figure 2-6 Directional Earth Fault Boundary System Angles..............................................................24
Figure 2-7 Measured Earth Fault ........................................................................................................25
Figure 2-8 Sensitive Earth Fault..........................................................................................................29
Figure 2-9 Restricted Earth Fault ........................................................................................................33
Figure 2-10 Negative Phase Sequence Overcurrent ............................................................................35
Figure 2-11 Undercurrent ......................................................................................................................38
Figure 2-12 Thermal Overload ..............................................................................................................40
Figure 2-13 Phase Under/Over Voltage................................................................................................42
Figure 2-14 Vx Under/Over Voltage......................................................................................................45
Figure 2-15 NPS Overvoltage ...............................................................................................................47
Figure 2-16 Neutral Overvoltage ...........................................................................................................49
Figure 2-17 Under/Over Frequency ......................................................................................................51
Figure 3-1 CB Fail ...............................................................................................................................53
Figure 3-2 Voltage Transformer Supervision ......................................................................................55
Figure 3-2 Bus Voltage Transformer Fail............................................................................................57
Figure 3-3 Current Transformer Supervision ......................................................................................58
Figure 3-4 Broken Conductor..............................................................................................................60
Figure 3-5 Trip Circuit Supervision......................................................................................................62
Figure 3-6 Magnetising Inrush Detector..............................................................................................63