Siemens Sentron 3VA - Page 6

Table of contents
3VA molded case circuit breakers with UL and IEC certification
4 Manual, 01/2019, L1V30435333-01
2.5.7 Ground-fault protection .......................................................................................................... 70
2.5.7.1 Measurement method 1: Vectorial summation (residual) current .......................................... 70
2.5.7.2 Measurement method 2: Direct detection .............................................................................. 72
2.5.8 Neutral conductor protection (N) ............................................................................................ 73
2.5.9 Zone-selective interlocking ZSI .............................................................................................. 76
2.6 Thermal-magnetic trip unit ..................................................................................................... 79
2.6.1 Thermal-magnetic trip unit (TMTU) ........................................................................................ 79
2.6.2 Application cases and trip unit types...................................................................................... 79
2.7 Electronic trip unit................................................................................................................... 80
2.7.1 Electronic trip unit (ETU) ........................................................................................................ 80
2.7.2 Connections ........................................................................................................................... 81
2.7.3 Arc energy reduction .............................................................................................................. 81
2.7.4 Protection functions ............................................................................................................... 83
2.7.5 Operator controls ................................................................................................................... 84
2.7.6 Load acceptance and load shedding - load management ..................................................... 94
2.7.7 Measuring with a Rogowski coil ............................................................................................. 95
3 Applications .......................................................................................................................................... 99
3.1 Use of the 3VA UL molded case circuit breakers in line protection ....................................... 99
3.1.1 Applications in line protection ................................................................................................ 99
3.1.2 Versions of the trip units ...................................................................................................... 102
3.1.2.1 Thermal-magnetic trip units ................................................................................................. 102
3.1.2.2 Electronic trip units ............................................................................................................... 105
3.1.3 Overview of 3VA UL molded case circuit breakers in line protection .................................. 132
3.2 Use as Motor Circuit Protector (MCP) for starter combinations .......................................... 134
3.3 Use of the 3VA UL molded case circuit breaker as a molded case switch (MCS) .............. 138
3.3.1 Compatibility of 3VA UL molded case switch and accessories ........................................... 140
3.4 Use of 3VA UL molded case circuit breaker in DC systems ................................................ 141
3.4.1 Introduction .......................................................................................................................... 141
3.4.2 Variants ................................................................................................................................ 142
3.4.3 Breaking capacity with direct current ................................................................................... 143
3.4.4 Recommended circuits for DC systems UL ......................................................................... 144
3.4.5 Recommended circuits for DC systems IEC ........................................................................ 146
3.5 Use of 3VA UL molded case circuit breakers in IT systems according to IEC 60947-2 ...... 148
3.5.1 Introduction .......................................................................................................................... 148
3.5.2 Selection criteria for 3VA UL molded case circuit breakers ................................................. 148
3.5.3 Fault situation ....................................................................................................................... 149
4 Accessories ......................................................................................................................................... 151
4.1 Overview - Accessories for 3VA UL molded case circuit breakers ...................................... 151
4.2 Internal accessories ............................................................................................................. 152
4.2.1 Mounting locations of 3VA UL molded case circuit breakers .............................................. 152
4.2.2 Auxiliary and alarm switches ................................................................................................ 156
4.2.3 Contact sequence diagrams ................................................................................................ 159
4.2.4 Technical specifications of auxiliary and alarm switches ..................................................... 160
4.2.5 Auxiliary releases ................................................................................................................. 162
4.2.6 Time-delay devices for undervoltage releases .................................................................... 166
4.2.7 COM060 communication module......................................................................................... 166
4.2.8 24 V module ......................................................................................................................... 167