5-204 D60 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUALGROUPED ELEMENTS CHAPTER 5: SETTINGS5Figure 5-107: Application of the PH DIST XFMR VOL/CUR CONNECTION settingsPHS DIST Z1 REACH — This setting defines the zone reach for the forward and reverse applications. In the non-directionalapplications, this setting defines the forward reach of the zone. The reverse reach impedance in non-directionalapplications is set independently. The reach impedance is entered in secondary ohms. The reach impedance angle isentered as the PHS DIST Z1 RCA setting.Zone 1 is characterized by transient overreach of less than 5% under source impedance ratios of up to 30. When setting anunder-reaching zone 1 for direct tripping and under-reaching pilot schemes (DUTT, PUTT) also consider other factors as perrules of distance relaying. In non-directional applications, this 5% transient accuracy applies to the forward reach only.To achieve specified operating speed of distance elements, the relay internally calculates source to line impedance ratio(SIR) from fault phasors. In these calculations, line impedance is estimated based on the zone 1 reach setting. Therefore, inorder to calculate the SIR value properly and to maintain the optimal operating speed of the distance elements, set zone 1reach with a regular 80 to 85% of the line impedance reach setting, even when zone 1 is disabled.PHS DIST Z1 RCA — This setting specifies the characteristic angle (similar to the "maximum torque angle" in previoustechnologies) of the phase distance characteristic for the forward and reverse applications. In the non-directionalapplications, this setting defines the angle of the forward reach impedance. The reverse reach impedance in the non-directional applications is set independently. The setting is an angle of reach impedance as shown in the distancecharacteristic figures earlier. This setting is independent from PHS DIST Z1 DIR RCA, the characteristic angle of an extradirectional supervising function.
