Schweitzer Engineering Laboratories SEL-701 - Page 16

701 Motor Protection Relay Date Code 20010719
List of Figures
xvi
Figure B.7 Start Logic.................................................................................B.23
Figure B.8 Remote Control Switches
Drive Remote Bits RB1 through RB4. ................................B.30
Figure B.9 Undervoltage Element Logic....................................................B.32
Figure B.10 Underpower Element Logic......................................................B.32
Figure B.11 Current Unbalance Element Logic. ..........................................B.33
Figure B.12 Phase Reversal Element Logic..................................................B.34
Figure B.13 Overcurrent Element Logic.......................................................B.35
Figure B.14 Power Factor Elements Logic. ..................................................B.36
Figure B.15 Overvoltage Element Logic. .....................................................B.37
Figure B.16 Over-/Underfrequency Element Logic......................................B.39
Figure B.17 Load-Jam Elements Logic. .......................................................B.40
Figure B.18 Load-Loss Logic; No Voltage Option.......................................B.40
Figure B.19 Load-Loss Logic; Voltage Option Included..............................B.41
Figure B.20 Reactive Power Elements Logic. ..............................................B.42
Figure B.21 Speed Switch Tripping Logic. ..................................................B.42
Appendix C: Modbus
®
RTU Communications Protocol
Appendix D: SEL-2020/2030 & SEL-701PC Compatibility Features
Appendix E: Motor Thermal Element
Figure E.1 Motor Thermal Limit Characteristic
Plotted With Motor Starting Current. ....................................E.4
Figure E.2 Electrical Analog of a Thermal System...................................... E.5
Figure E.3 Typical Induction Motor Current,
Torque, and Rotor Resistance versus Slip. ............................E.6
Figure E.4 Motor Starting Thermal Element................................................E.8
Figure E.5 Motor Running Thermal Element
With Resistance and Trip Level Undefined........................... E.9
Figure E.6 Calculating the Normal Operating
Energy Using Locked Rotor Trip Times. .............................. E.9
Figure E.7 Motor Running Thermal Element.............................................E.10
Appendix F: SEL-701 Relay Settings Sheets