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Devices and description of this sample SLD

  • 7RED 670: Main-1 Differential / Distance Protection
  • 7SD522: Main-2 Differential / Distance Protection
  • 7VK87: CB Fail Protection Relay with Backup DOC/DEF Protection for OHL bays1
  • 7KE85: Disturbance Recorder
  • 7SD82: Main-1/2 Cable Differential Protection
  • 7UT82: Low Impedance Restricted Earth Fault Protection
  • 7SJ82: CB Fail Protection Relay with Bac kup OC/EF Protection
  • 7SS85: Main-1/2 Centralized busbar Protection
  • MFM: Multifunction Meter with transducer outputs for NCC measurements and display for indication of measured values.
  • 6MD85: Bay Controller Unit (BCU)
  • 85X, 85R1, 85R2: 7PA27, Intertrip Receive Relay
  • F85: SWT3000, Intertrip Unit for OHL & UGC Bays

Following shows the ANSI code and functional

  • 21: Distance protection
  • 25: Synchrocheck
  • 50: Definite time overcurrent protection
  • 50N: Definite time earth fault protection
  • 50BF: Circuit-breaker failure protection
  • 51: Inverse time overcurrent protection
  • 51N: Inverse time earth fault protection
  • 64: Sensitive ground-fault protection
  • 67: Directional overcurrent protection
  • 67N: Directional earth fault protection
  • 68: Power swing blocking
  • 79: Automatic reclosing
  • 87: Differential protection
  • 87B: Busbar differential protection
  • FL: Fault Locator


  1. avatar

    Hi Saeed
    please share the document with me

    1. avatar

      please share the document with me