SIPROTEC 7SJ81

The SIPROTEC 7SJ81 is designed to be used for line protection of high and medium-voltage networks with grounded, low-resistance grounded, isolated or a compensated neutral point.

It provides 4 low-power current transformer inputs and 3 optional low-power voltage transformer inputs. With the same low-power current transformer (LPCT), a wide range of primary rated line currents can be covered. Objects with rated currents in the range of 20 A to 2500 A can be protected when using low-power current transformers.

Enquiry about SIPROTEC 7SJ81

DESCRIPTION

Basic Features

  • Instantaneous and definite time-overcurrent protection (phase/neutral) (50, 50N, 51, 51N)
  • Directional time-overcurrent protection (phase/ground) (67, 67N)
  • Directional sensitive ground fault detection (67Ns, 50Ns)
  • Overvoltage protection, zero-sequence system (59N)
  • Trip-circuit supervision (74TC)
  • Undercurrent monitoring (37)
  • Overload protection (49)
  • Undervoltage/overvoltage protection (27/59)
  • Forward-power, reverse-power protection (32)
  • Overfrequency/underfrequency protection(81O/U)
  • Circuit-breaker failure protection (50B/F)
  • Automatic reclosing (79)
  • Fault locator (FL)
  • Lockout (86)