Protective Functions

Base Package

• Overexcitation (V/Hz) (24)

• Phase Undervoltage (27)

• Directional power sensitive triple‑setpoint Reverse Power, Low Forward

Power or Overpower detection, one of which can be used for sequential

tripping (32)

• Dual‑zone, offset‑mho Loss of Field (40), which may be applied with

undervoltage controlled accelerated tripping

• Sensitive Negative Sequence Overcurrent protection and alarm (46)

• Instantaneous Phase Overcurrent (50)

• Inadvertent Energizing (50/27)

• Generator Breaker Failure (50BF)

• Instantaneous Neutral Overcurrent (50N)

• Inverse Time Neutral Overcurrent (51N)

• Three‑phase Inverse Time Overcurrent (51V) with voltage control and

voltage restraint.

• Phase Overvoltage (59)

• Neutral Overvoltage (59N)

• Multi‑purpose Overvoltage (59X)

• VT Fuse‑Loss Detection and blocking (60FL)

• Residual Directional Overcurrent (67N)

• Four‑step Over/Underfrequency (81)

• Phase Differential Current (87)

• Ground (zero sequence) Differential Current (87GD)

• IPSlogic takes the contact input status and function status and generates

outputs by employing (OR, AND, and NOT) boolean logic and a timer.