Siemens SIRIUS 3RT Series System Manual page 14

Table of contents
5.7 Connection ................................................................................................................................ 513
5.7.1 Connection of 3RU21 overload relay ........................................................................................ 514
5.7.2 Connection of 3RB30/3RB31 overload relays .......................................................................... 515
5.8 Operation................................................................................................................................... 516
5.8.1 Setting the current..................................................................................................................... 516
5.8.2 Setting the tripping class/ground-fault detection (3RB31) ........................................................ 517
5.8.3 RESET after release ................................................................................................................. 517
5.8.4 TEST function ........................................................................................................................... 520
5.8.5 Response of the auxiliary contacts ........................................................................................... 522
5.9 Accessories ............................................................................................................................... 523
5.9.1 Accessories ............................................................................................................................... 523
5.9.2 Terminal support for stand-alone assembly.............................................................................. 524
5.9.2.1 Description ................................................................................................................................ 524
5.9.2.2 Mounting/Disassembly .............................................................................................................. 524
5.9.3 Mechanical remote RESET (release slide) ............................................................................... 527
5.9.3.1 Description ................................................................................................................................ 527
5.9.3.2 Mounting/Disassembly .............................................................................................................. 527
5.9.4 Mechanical remote RESET (cable release).............................................................................. 529
5.9.4.1 Description ................................................................................................................................ 529
5.9.4.2 Mounting/Disassembly .............................................................................................................. 530
5.9.5 Module for electrical remote RESET (3RU21 only) .................................................................. 531
5.9.5.1 Description ................................................................................................................................ 531
5.9.5.2 Connecting the remote RESET................................................................................................. 531
5.9.5.3 Mounting/Disassembly .............................................................................................................. 532
5.9.6 Sealable cover .......................................................................................................................... 533
5.9.6.1 Description ................................................................................................................................ 533
5.9.6.2 Mounting.................................................................................................................................... 533
5.9.7 Covers for ring cable lug connections....................................................................................... 535
5.9.7.1 Description ................................................................................................................................ 535
5.10 Technical data........................................................................................................................... 536
5.10.1 Performance features................................................................................................................ 536
5.10.1.1 General data ............................................................................................................................. 536
5.10.1.2 Protection functions - overview ................................................................................................. 536
5.10.1.3 Equipment ................................................................................................................................. 537
5.10.1.4 Configuration of load feeders .................................................................................................... 537
5.10.1.5 Features of overload relays....................................................................................................... 538
5.10.2 3RU21 ....................................................................................................................................... 539
5.10.2.1 General technical data .............................................................................................................. 539
5.10.2.2 Main circuit ................................................................................................................................ 540
5.10.2.3 Conductor cross-sections main circuit ...................................................................................... 541
5.10.2.4 Auxiliary circuit .......................................................................................................................... 543
5.10.2.5 Conductor cross sections, auxiliary circuit ................................................................................ 544
5.10.3 3RB30/3RB31 ........................................................................................................................... 546
5.10.3.1 General technical data .............................................................................................................. 546
5.10.3.2 Main circuit ................................................................................................................................ 548
5.10.3.3 Conductor cross-sections main circuit ...................................................................................... 549
5.10.3.4 Auxiliary circuit .......................................................................................................................... 550
5.10.3.5 Conductor cross sections, auxiliary circuit ................................................................................ 551
5.11 Dimension drawings (dimensions in mm) ................................................................................. 552
5.11.1 Dimension drawings for 3RU21 thermal overload relays.......................................................... 552
5.11.2 Dimension drawings for 3RB30/3RB31 solid-state overload relays ......................................... 556
5.12 Circuit diagrams ........................................................................................................................ 559
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SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03