New Siemens vacuum generator circuit-breaker for operating currents up to 6300 A and short-circuit breaking currents up to 72 kA
Erlangen, Germany, June 12, 2006
Siemens Power Transmission and Distribution (PTD) has expanded its range of products upwards with the new high current and generator circuit breaker 3AH37. The circuit breaker can handle operating currents up to 6300 A at 17.5 kV and short-circuit breaking currents up to 72 kA. The first vacuum generator circuit-breaker worldwide type-tested according to the criteria of the generator circuit-breaker standard IEE Std C37.013 was the 3AH38. With a rated voltage of 17.5 kV, it switches operating currents up to 4000 A and short-circuit breaking currents up to 72 kA. These circuit-breakers developed for switching functions in power plants and in industry can be operated with no maintenance, thereby reducing life cycle costs.
High current and generator circuit-breakers are used predominantly in power plants and in industry for switching generators and high powers. In these applications, the circuit-breakers are exposed to considerable thermal and mechanical stressing. The new circuit-breaker features a modular design that allows it to meet these requirements. With this design, the best materials can be used in each case for the current path, magnetic flux and cooling. The modular structure also allows the circuit-breaker to be installed flat. For this purpose the cooling elements are rotated by 90°, and even in this position optimum cooling through free convection is still possible. In this way circuit-breakers 3AH37 and 3AH38 can both operate without any additional forced-air cooling.
While the design of the post insulator improves the mechanical stability of the circuit-breakers, the vertical arrangement of the vacuum tubes ensures a compact design. The special construction ensures that no solid insulation is required, which considerably reduces the risk of fire.
The new circuit-breaker 3AH37 rounds out the Siemens portfolio of high current and generator circuit-breakers for rated operating currents from 3150 A to 6300 A and for short-circuit breaking currents from 50 kA to 72 kA at a rated voltage of 17.5 kV.
The Siemens Power Transmission and Distribution Group (PTD), headquartered in Erlangen, Germany, is one of the leading global players in its market sector. As a product supplier, system integrator, solution designer and service provider, Siemens PTD ensures - for utilities and industry alike - the efficient and reliable transmission of electrical energy from the power plant to the consumer. With a worldwide workforce of about 25,850 and operations in nearly 90 countries, PTD had sales of 4.3 billion euros in fiscal 2005 (ended September 30). Further information at: www.siemens.com/ptd.
Reference Number: PTD M 200606.427 e