Schweitzer Engineering Laboratories SEL-751 - Page 16

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SEL-751 Relay Instruction Manual Date Code 20170927
List of Figures
Figure 2.27 SEL-751 Provides Overcurrent Protection for a Transformer Bank With a Tertiary
Winding (Wye-Connected PTs)........................................................................................ 2.36
Figure 2.28 SEL-751 Provides Overcurrent Protection for an Industrial Distribution Feeder
(Core-Balance Current Transformer Connected to Channel IN)...................................... 2.37
Figure 2.29 SEL-751 Provides Overcurrent Protection for a High-Impedance or Low-Impedance
Grounded System (Wye-Connected PTs)......................................................................... 2.38
Figure 2.30 SEL-751 Provides Overcurrent Protection for a Petersen Coil-Grounded System
(Wye-Connected PTs)....................................................................................................... 2.39
Figure 2.31 SEL-751 Provides Overcurrent Protection for an Ungrounded System
(Wye-Connected PTs)....................................................................................................... 2.40
Figure 2.32 SEL-751 Provides Overcurrent Protection for an Ungrounded System
(Open-Delta Connected PTs, Broken-Delta 3V0 Connection)......................................... 2.41
Figure 2.33 SEL-751 With a 2 AVI/4 AFDI Option Card and the Fiber-Optic-Based Point-Sensor...... 2.42
Figure 2.34 Black-Jacketed Fiber installation Example.......................................................................... 2.43
Figure 2.35 Point-Sensor Assembly ........................................................................................................ 2.43
Figure 2.36 Point-Sensor Installation ...................................................................................................... 2.43
Figure 2.37 Point-Sensor Directivity (0–360° Around the Mounting Plane).......................................... 2.44
Figure 2.38 Point-Sensor Directivity (Front to Back, Above the Mounting Plane) ................................ 2.44
Figure 2.39 Point-Sensor Directivity (Left to Right, Above the Mounting Plane).................................. 2.45
Figure 2.40 Clear-Jacketed Fiber Sensor Assembly................................................................................ 2.45
Figure 2.41 Clear-Jacketed Fiber Sensor Mounting Example................................................................. 2.46
Figure 2.42 Clear-Jacketed Fiber Sensor Components (V-Pin Style)...................................................... 2.46
Figure 2.43 Clear-Jacketed Fiber Sensor Showing Transition From Clear- to Black-Jacketed
Fiber Section..................................................................................................................... 2.46
Figure 2.44 Switchgear Application Example......................................................................................... 2.47
Figure 2.45 Bare-Fiber Sensor Assembly With Two Splices .................................................................. 2.48
Figure 2.46 Point Sensor Assembly......................................................................................................... 2.48
Figure 2.47 Bare-Fiber Sensor Assembly With Two Additional ST Splice Connectors......................... 2.49
Figure 2.48 Point Sensor Assembly With Two V-Pin Splice Connectors ............................................... 2.50
Figure 3.1 Serial Port Communications Dialog Box............................................................................... 3.2
Figure 3.2 Serial Port Communication Parameters Dialog Box.............................................................. 3.3
Figure 3.3 Network Communication Parameters Dialog Box................................................................. 3.3
Figure 3.4 Communications Menu .......................................................................................................... 3.3
Figure 3.5 Device Response to the ID Command ................................................................................... 3.4
Figure 3.6 Selection of Drivers................................................................................................................ 3.7
Figure 3.7 Update Part Number............................................................................................................... 3.8
Figure 3.8 New Setting Screen ................................................................................................................ 3.8
Figure 3.9 Expressions Created With Expression Builder .................................................................... 3.10
Figure 3.10 Composite Screens for Retrieving Events............................................................................ 3.11
Figure 3.11 Saving the Retrieved Event .................................................................................................. 3.12
Figure 3.12 Device Overview Screen ...................................................................................................... 3.13
Figure 3.13 Control Screen...................................................................................................................... 3.14
Figure 3.14 Remote Operation Selection................................................................................................. 3.15
Figure 3.15 Language Support Options................................................................................................... 3.15
Figure 3.16 Spanish Settings QuickSet Display...................................................................................... 3.16
Figure 3.17 Spanish Control Window (Ventana de Control) Display ..................................................... 3.17
Figure 4.1 Low-Energy Analog Voltage Sensor (Capacitive Voltage Divider) ....................................... 4.7
Figure 4.2 Instantaneous Overcurrent Element Logic........................................................................... 4.14
Figure 4.3 Instantaneous Overcurrent Element Pickup Time Curve ..................................................... 4.16
Figure 4.4 Instantaneous Overcurrent Element Reset Time Curve ....................................................... 4.16
Figure 4.5 Phase Time-Overcurrent Elements 51AT, 51BT, and 51CT ................................................ 4.18
Figure 4.6 Maximum Phase Time-Overcurrent Elements 51P1T and 51P2T....................................... 4.19
Figure 4.7 Negative-Sequence Time-Overcurrent Element 51QT ........................................................ 4.20
Figure 4.8 Neutral Time-Overcurrent Elements 51N1T and 51N2T..................................................... 4.21
Figure 4.9 Residual Time-Overcurrent Elements 51G1T and 51G2T................................................... 4.22
Figure 4.10 U.S. Moderately Inverse Curve: U1.....................................................................................4.24
Figure 4.11 U.S. Inverse Curve: U2 ........................................................................................................ 4.24
Figure 4.12 U.S. Very Inverse Curve: U3................................................................................................ 4.24