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3AK7 Vacuum Circuit-Breakers · Siemens HG 11.06 · 2017

3AK7 Vacuum Circuit-Breakers Medium-Voltage Equipment Catalog HG 11.06 · 2017 Invalid: Katalog HG 11.06 · 2014 Standards, maintenance-free design Ambient conditions and operating conditions Construction and mode of operation Technical data and basic equipment Equipment Selection Order number structure Selection of secondary equipment Selection of additional equipment Accessories and spare parts Technical Data Selection of basic types, circuit-breakers Electrical data, dimensions and masses Circuit diagrams Dimension drawings Operating times, short-circuit protection of motors 34 Consumption data...

3AK7 Vacuum Circuit-Breakers · Siemens HG 11.06 · 2017

Description Contents Pole assemblies Operating mechanism Trip-free mechanism Circuit-breaker tripping signal Industrial application: Refinery Switching medium Standards, maintenance-free design Construction and mode of operation Ambient conditions and operating conditions Ambient conditions Current carrying capacity Dielectric strength Technical data and basic equipment 3AK7 Vacuum Circuit-Breakers · Siemens HG 11.06 · 2017

Description General Vacuum Circuit-Breaker 3AK7 from 7.2 to 17.5 kV – The Powerful in Compact Design Circuit-breakers must make and break all currents in the range of their ratings: From small inductive and capacitive load currents to high short-circuit currents. Thereby, they control all fault conditions in the network. Due to its high performance, the vacuum circuit-breaker 3AK7 is perfectly suitable for operating industrial applications and generators. The circuit-breaker can be used for load currents up to 4000 A, and is capable to break short-circuit currents up to 50 kA. Due to the lean...

Description Design and mode of operation The vacuum circuit-breaker consists of the pole assemblies (1) and the operating mechanism box (2). Each of the three pole assemblies is supported by its pole shell, which is fastened to the pole plate (7). The switching movement is transferred by means of operating rods (6). The vacuum switching technology, proven and fully developed for more than 40 years, serves as arc-quenching principle by using vacuum interrupters (4). One pole assembly (1) of the 3AK7 vacuum circuit-breaker consists of the upper interrupter support (3), the vacuum interrupter (4)...

Description Construction and mode of operation, standards, maintenance-free design Releases A release is a device which transfers electrical commands from an external source, such as a control room, to the latching mechanism of the vacuum circuit-breaker so that it can be opened or closed. Apart from the closing solenoid, the maximum possible equipment is one shunt release and two other releases. For release combinations, refer to page 16. • The closing solenoid unlatches the charged closing spring of the vacuum circuit-breaker, closing it by electrical means. It is suitable for AC or DC voltage....

Description Ambient conditions, current carrying capacity and dielectric strength Ambient conditions The vacuum circuit-breakers are designed for the normal o perating conditions defined in IEC 62271-100. Condensation can occasionally occur under the ambient conditions shown opposite. 3AK7 vacuum circuit-breakers are suitable for use in the following climatic classes according to IEC 60721, Part 3-3: Class 3K4 1) 3K6 2), 3Z2, 3Z5 Class 3B1 Class 3M2 Class 3C2 3) Class 3S2 4) Climatic ambient conditions: Biological ambient conditions: Mechanical ambient conditions: Chemically-active substances:...

Technical data and basic equipment Generator circuit-breaker (IEC/IEEE 62271-37-013:2015) Rated normal current Ir A 1250; 2000; 2500; 3150; 4000 (with forced cooling) withstand voltage Ud Rated short-circuit breaking current Isc kA 50 40 50 40 50 40 50 * For generator switching applications: Ud and Up fulfill the specification with rated voltage 15 kV acc. to IEC/IEEE 62271-37-013:2015 and 17.5 kV acc. to IEC 62271-100 3rd release Without Shunt release, undervoltage release, Max. 3 releases can be c.t.-operated release combined (for possible release 3AK7 Vacuum Circuit-Breakers ■ Siemens HG 11.06...

Equipment Selection Contents Equipment Selection Order number structure Selection of basic types, circuit-breakers Voltage level 7.2 kV to 17.5 kV Selection of secondary equipment Operating voltage of the operating mechanism 15 Release combination 16 Operating voltage of the closing solenoid 17 Operating voltage of the 1st shunt release 17 Operating voltage of the 2nd release 18 Operating voltage of the 3rd release 18 Circuit-breaker installation equipment/ circuit-breaker design 18 Auxiliary switch, secondary connection, interlocking 19 Languages of operating instructions and rating plate, as...

Equipment Selection Order number structure Order number structure Special versions («) The vacuum circuit-breakers consist of a primary and a secondary part. The relevant data make up the 16-digit order number. The primary part covers the main electrical data of the circuit-breaker poles. The secondary part covers all auxiliary devices which are necessary for operating and controlling the vacuum circuit-breaker. For special versions, “-Z“ is added to the order number and a descriptive order code follows. If several built-on components and special versions are required, the suffix “-Z“ is listed...

Special version (available for all 17.5 kV circuit-breakers) Ud = 42 kV 3AK7 Vacuum Circuit-Breakers ■ Siemens HG 11.06 ■ 2017 The PCD is selected at the 14th position of the order number With forced cooling

Selection of secondary equipment 7.2 kV generator circuit-breaker Position: Order codes Hlz E 1 3 1) The PCD is selected at the 14th position of the order number 2) With forced cooling 3AK7 Vacuum Circuit-Breakers ■ Siemens HG 11.06 ■ 2017