Figure 4-5. Setting Group Selection Screen .............................................................................................. 4-7
Figure 4-6. Instantaneous Overcurrent Logic Blocks ................................................................................ 4-9
Figure 4-7. BESTlogic Function Element Screen, Neutral (50TN) .......................................................... 4-10
Figure 4-8. Overcurrent Protection Screen, 50T Tab .............................................................................. 4-12
Figure 4-9. Time Overcurrent Logic Blocks ............................................................................................. 4-13
Figure 4-10. BESTlogic Function Element Screen, Neutral (151N) ........................................................ 4-14
Figure 4-11. Time Overcurrent Protection Screen, 51 Tab ..................................................................... 4-15
Figure 4-12. Curve Coefficients ............................................................................................................... 4-17
Figure 4-13. Sequence Components for an A-B Fault ............................................................................ 4-18
Figure 4-14. Phase-to-Phase Fault Magnitude ....................................................................................... 4-18
Figure 4-15. Overexcitation Logic Block .................................................................................................. 4-20
Figure 4-16. BESTlogic Function Element Screen, 24 ............................................................................ 4-22
Figure 4-17. Voltage Protection Screen, 24 Tab ..................................................................................... 4-23
Figure 4-18. Time Shown on Vertical Axis .............................................................................................. 4-24
Figure 4-19. Time Shown on Horizontal Axis .......................................................................................... 4-24
Figure 4-20. Voltage Protection Screen, Overexcitation (24) Tab .......................................................... 4-25
Figure 4-21. Inverse Time Delay and Reset Time ................................................................................... 4-26
Figure 4-22. Phase Undervoltage/Overvoltage Logic Blocks .................................................................. 4-26
Figure 4-23. BESTlogic Function Element Screen, Phase (27P) ............................................................ 4-27
Figure 4-24. Voltage Protection Screen, 27P/127P Tab ......................................................................... 4-28
Figure 4-25. Auxiliary Undervoltage/Overvoltage Logic Blocks .............................................................. 4-29
Figure 4-26. BESTlogic Function Element Screen, 59X ......................................................................... 4-31
Figure 4-27. Voltage Protection Screen, 59X/159X Tab ......................................................................... 4-32
Figure 4-28. Negative-Sequence Overvoltage Logic Block .................................................................... 4-33
Figure 4-29. BESTlogic Function Element Screen, Negative Sequence (47) ......................................... 4-34
Figure 4-30. Voltage Protection Screen, 47 Tab ..................................................................................... 4-35
Figure 4-31. Over/Under Frequency Logic Block .................................................................................... 4-36
Figure 4-32. BESTlogic Function Element Screen, 81 ............................................................................ 4-37
Figure 4-33. Voltage Protection Screen, INH/81/181/281/381/481/581 Tab .......................................... 4-38
Figure 4-34. Breaker Failure Logic Block ................................................................................................ 4-39
Figure 4-35. BESTlogic Function Element Screen, Breaker Failure ....................................................... 4-41
Figure 4-36. Breaker Failure Screen ....................................................................................................... 4-42
Figure 4-37. General Purpose Logic Timers Logic Block ........................................................................ 4-43
Figure 4-38. Mode 1, PU/DO (Pickup/Dropout Timer) ............................................................................ 4-43
Figure 4-39. Mode 2, One-Shot Nonretriggerable Timer......................................................................... 4-44
Figure 4-40. Mode 3, One Shot Retriggerable Timer .............................................................................. 4-44
Figure 4-41. Mode 4, Oscillator ............................................................................................................... 4-44
Figure 4-42. Mode 5, Integrating Timer ................................................................................................... 4-45
Figure 4-43. Mode 6, Latch ..................................................................................................................... 4-45
Figure 4-44. BESTlogic Function Element Screen, 62 ............................................................................ 4-46
Figure 4-45. Logic Timers Screen ........................................................................................................... 4-47
Figure 4-46. Reclosing Logic Block ......................................................................................................... 4-48
Figure 4-47. Recognition Dropout Timing ............................................................................................... 4-48
Figure 4-48. 79SCB Logic ....................................................................................................................... 4-49
Figure 4-49. BESTlogic Function Element Screen, 79 ............................................................................ 4-50
Figure 4-50. Reclosing Screen ................................................................................................................ 4-51
Figure 4-51. S#-79SCB=1/2/3/4/5 Logic Timing Diagram ....................................................................... 4-53
Figure 4-52. S#-79SCB=2/3/4/5 Logic Timing Diagram .......................................................................... 4-53
Figure 4-53. BESTlogic Function Element Screen, Reclosing (Zone Sequence Logic) ......................... 4-54
Figure 4-54. Overall Logic Diagram for Reclosing .................................................................................. 4-55
Figure 4-55. Synchronism-Check Logic Block ........................................................................................ 4-56
Figure 4-56. BESTlogic Function Element Screen, 25 ............................................................................ 4-57
Figure 4-57. Voltage Protection Screen, 25 Tab ..................................................................................... 4-58
Figure 4-58. 25VM Logic ......................................................................................................................... 4-60
Figure 4-59. Fuse Loss Detection Logic Block ........................................................................................ 4-60
Figure 4-60. 60FL Element Logic ............................................................................................................ 4-61
Figure 4-61. Reporting and Alarms Screen, VT Monitor Tab .................................................................. 4-62
Figure 4-62. Virtual Selector Switches Logic Block ................................................................................. 4-63
Figure 4-63. BESTlogic Function Element Screen, 43 ............................................................................ 4-64
Figure 4-64. Virtual Breaker Control Switch Logic Block ........................................................................ 4-65
Figure 4-65. Virtual Breaker Control Switch State Diagram .................................................................... 4-66
9376700990 Rev M
BE1-700 Protection and Control
iii
