4–240 869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUALPROTECTION CHAPTER 4: SETPOINTSSIGNAL INPUTRange: Positive Impedance 1, Positive Impedance 2Default: Positive Impedance 1This setting provides the selection for the positive sequence impedance which iscalculated by terminal side or neutral side CT. Positive sequence impedance 1 iscalculated using 3-phase J1 currents and 3-phase J2 voltages. Positive sequenceimpedance 2 is calculated using 3-phase K1 currents and 3-phase J2 voltages.MHO FORWARD REACHRange: 0.10 to 500.00 ohms in steps of 0.01 ohmsDefault: 2.00 ohmsThis setting specifies the forward reach of the mho characteristic. The reach impedanceis entered in secondary ohms. The reach impedance angle is fixed to 90 degrees.MHO REVERSE REACHRange: 0.10 to 500.00 ohms in steps of 0.01 ohmsDefault: 2.00 ohmsThis setting specifies the reverse reach of the mho characteristic. The reach impedanceis entered in secondary ohms. The reach impedance angle is fixed to -90 degrees.RIGHT BLINDERRange: 0.10 to 500.00 ohms in steps of 0.01 ohmsDefault: 2.00 ohmsThis setting defines the right blinder position of the blinder characteristic along with theresistive axis of the impedance plane, expressed ins secondary ohms. The angularposition of the blinder is adjustable with the use of the BLINDERS RCA setting.LEFT BLINDERRange: 0.10 to 500.00 ohms in steps of 0.01 ohmsDefault: 2.00 ohmsThis setting defines the left blinder position of the blinder characteristic along with theresistive axis of the impedance plane, expressed ins secondary ohms. The angularposition of the blinder is adjustable with the use of the BLINDERS RCA setting.BLINDER RCARange: 40 to 90° in steps of 1°Default: 90°This setting defines the angular position of the left and right blinders.PICKUP DELAYRange: 0.000 to 1.000 s in steps of 0.001 sDefault: 0.100 sThis setting should be set to detect the fastest expected unstable power swing andproduce out-of-step tripping in a secure manner. This timer defines the interval that theimpedance locus must spend between the left and right blinders to establish the out-of-step tripping signal. This time delay must be set shorter than the time required for theimpedance locus to travel between the left and right blinders during the fastestexpected out-of-step. Setting the delay too long can reduce dependability.
