Siemens SENTRON 3VA1, Руководство пользователя

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Table of contents
3VA molded case circuit breakers with IEC certificate
4
Manual, 03/2019, A5E03603177010-03
2.6.4 Overload protection (L) .......................................................................................................75
2.6.5 Short-time delayed short-circuit protection (S) ....................................................................76
2.6.6 Instantaneous short-circuit protection (I) .............................................................................76
2.6.7 Ground-fault protection (G) .................................................................................................76
2.6.8 Neutral conductor protection (N) .........................................................................................79
2.6.9 Zone selective interlocking (ZSI) .........................................................................................82
2.7 Thermal-magnetic trip unit ..................................................................................................85
2.7.1 Thermal trip unit (L) ............................................................................................................85
2.7.2 Magnetic trip unit with short-circuit protection (I) .................................................................85
2.7.3 Application cases and trip unit types ...................................................................................86
2.8 Electronic trip unit ...............................................................................................................87
2.8.1 Connections .......................................................................................................................89
2.8.2 Protection functions ............................................................................................................90
2.8.3 Operator controls ...............................................................................................................93
2.8.4 Load acceptance and load shedding - load management ..................................................102
2.8.5 Measuring with a Rogowski coil ........................................................................................103
3 Applications............................................................................................................................... 109
3.1
3VA IEC trip units .............................................................................................................109
3.2 Line protection applications of 3VA molded case circuit breakers ......................................110
3.2.1 Variants............................................................................................................................111
3.2.1.1 Thermal-magnetic trip units ..............................................................................................111
3.2.1.2 Electronic trip units ...........................................................................................................115
3.2.2 Overview of 3VA molded case circuit breakers in line protection applications ....................140
3.3 Motor protection applications of 3VA molded case circuit breakers ...................................144
3.3.1 3VA molded case circuit breakers for starter protection.....................................................145
3.3.2 3VA molded case circuit breakers for motor protection......................................................148
3.3.2.1 3VA2 motor protection circuit breaker up to 500 A, tested according to
IEC EN 60947-4-1 ............................................................................................................149
3.3.2.2 3VA2 motor protection breaker as tested motor protection combination, 3VA2 with
3RT ..................................................................................................................................150
3.3.2.3 Protection functions of 3VA2 molded case circuit breakers for motor protection ................150
3.3.3 ETU350M electronic trip unit ............................................................................................155
3.3.4 5-series and 8-series electronic trip units ..........................................................................158
3.3.4.1 ETU550M electronic trip unit ............................................................................................159
3.3.4.2 ETU860M electronic trip unit ............................................................................................161
3.4 Use of 3VA1 molded case circuit breakers as switch disconnectors ..................................165
3.4.1 Overview of 3VA1 as switch disconnectors .......................................................................169
3.4.2 Upstream protection of switch disconnectors ....................................................................170
3.5 DC network applications of 3VA molded case circuit breakers ..........................................172
3.5.1 Variants............................................................................................................................173
3.5.2 Breaking capacity with direct current.................................................................................174
3.5.3 Recommended circuit configurations for DC systems .......................................................175
3.6 Applications of the 3VA molded case circuit breaker with frequency converters ................177
3.7 400 Hz network applications of 3VA molded case circuit breakers ....................................179
3.8 IT system applications of 3VA molded case circuit breakers .............................................181
3.8.1 Selection criteria for 3VA molded case circuit breakers .....................................................181
3.8.2 Fault situation ...................................................................................................................182