Loss-Of-Potential Logic153
Table 4.1 LOP Logic Inputs153
Figure 4.1 Loss-Of-Potential Logic153
Load-Encroachment Logic156
Figure 4.2 Load-Encroachment Logic156
Table 4.2 Load-Encroachment Settings Ranges157
Figure 4.3 Migration of Apparent Positive-Sequence Impedance for a Fault Condition159
Directional Control for Neutral Ground and Residual Ground Overcurrent Elements161
Figure 4.4 General Logic Flow of Directional Control for Neutral Ground and Residual Ground Overcurrent Elements (Excluding Ungrounded/High-Impedance Grounded Systems)162
Table 4.3 Available Ground Directional Elements163
Table 4.4 Best Choice Ground Directional™ Logic163
Figure 4.5 General Logic Flow of Directional Control for Neutral Ground and Residual Ground Overcurrent Elements (Ungrounded/High-Impedance Grounded Systems; ORDER = U)163
Table 4.5 Ground Directional Element Availability by Voltage Connection Settings165
Figure 4.6 Internal Enables (32QE and 32QGE) Logic for Negative-Sequence Voltage-Polarized Directional Elements171
Figure 4.7 Internal Enables (32VE and 32IE) Logic for Zero-Sequence Voltage-Polarized and Channel in Current-Polarized Directional Elements172
Figure 4.8 Internal Enable (32NE) Logic for Zero-Sequence Voltage-Polarized Directional Elements (Low-Impedance Grounded, Petersen Coil Grounded, and Ungrounded/High-Impedance Grounded Systems)173
Figure 4.9 Negative-Sequence Voltage-Polarized Directional Element for Neutral Ground and Residual Ground Overcurrent Elements174
Figure 4.10 Zero-Sequence Voltage-Polarized Directional Element175
Figure 4.11 Channel in Current-Polarized Directional Element176
Figure 4.12 Zero-Sequence Voltage-Polarized Directional Element (Low-Impedance Grounded Systems)177
Figure 4.13 Wattmetric and Incremental Conductance Directional Elements (Petersen Coil Grounded Systems)178
Figure 4.14 Zero-Sequence Voltage-Polarized Directional Element (Ungrounded/High-Impedance Grounded Systems)179
Figure 4.15 Routing of Directional Elements to Residual Ground Overcurrent Elements180
Figure 4.16 Routing of Direction Elements to Neutral Ground Overcurrent Elements180
Figure 4.17 Direction Forward/Reverse Logic for Residual Ground Overcurrent Elements181
Figure 4.18 Direction Forward/Reverse Logic for Neutral Ground Overcurrent Elements182
Directional Control for Negative-Sequence and Phase Overcurrent Elements183
Figure 4.19 General Logic Flow of Directional Control for Negative-Sequence and Phase Overcurrent Elements183
Figure 4.20 Negative-Sequence Voltage-Polarized Directional Element for Negative-Sequence and Phase Overcurrent Elements186
Figure 4.21 Positive-Sequence Voltage-Polarized Directional Element for Phase Overcurrent Elements187
Figure 4.22 Routing of Directional Elements to Negative-Sequence and Phase Overcurrent Elements188
Figure 4.23 Direction Forward/Reverse Logic for Negative-Sequence Overcurrent Elements189
Figure 4.24 Direction Forward/Reverse Logic for Phase Overcurrent Elements190
Directional Control Settings191
Table 4.6 Directional Control Settings Not Made for Particular Conditions192
Table 4.7 Overcurrent Elements Controlled by Level Direction Settings DIR1-DIR4192
Table 4.8 Z Constant for Z2R Setting195
Table 4.9 Z Constant for Z0R Setting200
Figure 4.25 Zero-Sequence Impedance Network and Relay Polarity201
Figure 4.26 Zero-Sequence Impedance Plot for Solidly-Grounded, Mostly Inductive System201
Figure 4.27 Zero-Sequence Impedance Network for Ground Fault on Feeder 1204
Figure 4.28 Wattmetric Element Operation for Ground Fault on Feeder 1205
Table 4.10 Affect of Global Settings VSCONN and PTCONN on Petersen Coil Directional Elements208
Directional Control Provided by Torque Control Settings210

Section 5: Trip and Target Logic Trip Logic212

Section 6: Close and Reclose Logic Close Logic250

Section 8: Breaker Monitor, Metering, and Load Profile Functions326

Section 9: Setting the Relay Introduction372

Section 10: Serial Port Communications and Commands466

SEL-351S Relay Command Summary509

Section 11: Front-Panel Interface513

Section 13: Testing and Troubleshooting587

Appendix A: Firmware and Manual Versions Firmware602

Table A.2 Instruction Manual Revision History606

Appendix B: SEL-300 Series Relays Firmware Upgrade Instructions617

Appendix C: SEL Distributed Port Switch Protocol639

Appendix D: Configuration, Fast Meter, and Fast Operate Commands643

Appendix E: Compressed ASCII Commands657

Appendix F: Setting Negative-Sequence Overcurrent Elements667

Appendix G: Setting SEL OGIC Control Equations675

Appendix H: Distributed Network Protocol691

Appendix I: MIRRORED BITS Communications (in Firmware Versions 6 and 7) Overview716

Appendix J: SEL-351S Fast SER Protocol725

Ac Sel Erator733

Appendix K: Acseleratorquickset SEL-5030 Software733

Appendix Lsel Synchrophasors737

SEL-351S Relay Command Summary751

Operating Temperature	-40°C to +85°C
Frequency	50/60 Hz
Current Rating	5 A
Communication Protocols	DNP3, Modbus
Dimensions	5.5 x 5.5 x 5.5 inches
Mounting	Panel or DIN rail
Protection Functions	Overcurrent
Outputs	4
Enclosure	Metal
Inputs	Analog and digital inputs

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