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Circuit breakers

We offer live tank and dead tank circuit breakers as well as hybrid solutions combining different functions in a compact design, such as our dead tank compact (DTC) and our disconnecting circuit breakers (DCB). All of our products are manufactured based on our proven modular design and are available with porcelain or composite insulators. Choose the right product for your specific requirement from our portfolio.

Whether you generate, transmit or distribute energy, our Power Engineering Guide is a practical resource that will support you in your work.
Order Power Engineering Guide

Product overview

Our circuit breaker technology

The technology of our products sets international trends. We continuously ensure our high quality through optimized production processes, constant product development and a certified quality management system.

Advantages:

  • Over 100 years of operating experience
  • Many years of experience with special applications, e.g. in extremely hot and cold temperatures, or in the event of earthquakes
  • Close customer contact and quick accessibility thanks to our global production network and 24-hour service
  • A strong platform concept for interrupter units and operating mechanisms ensures competitive prices as well as low maintenance and training costs
  • Everything from a single source: installation, maintenance, training, technical advice
  • Replacement parts and maintenance accessories for all Siemens circuit breakers available for at least 25 years after delivery
  • Extremely low gas leakage rate of less than 0.1% per year (IEC requires a maximum of 0.5% per year)

Modular Design

Siemens high-voltage circuit breakers, regardless of type or voltage range, are designed in a well proven modular platform concept. This leads to a wide variety of circuit breaker types and strong flexibility with regard to various applications according to our customers’ requirements.

 

The main components, such as the operating mechanism, control system, base frame, kinematic chain and insulator designs are identical and based on decades of manufacturing and operating experience. Our GIS switchgear range also includes the same interrupter units, operating mechanisms and control elements. By applying this proven modular design not only at our lead factory in Germany, but also within our global manufacturing network, we are able to fulfill the highest expectations regarding availability and reliability at eminently competitive prices.

Quenching principle

Our complete 3AP family up to 800 kV and above relies on our arc-quenching principles, either the self-compression or the dynamic self-compression principle using the thermal energy of the arc. Siemens patented this method of arc quenching in 1973 and has continued to develop the technology of the self-compression interrupter unit ever since. In short-circuit breaking operations, the actuating energy required is reduced to the energy needed for mechanical contact movement.

 

Drive systems

Stored-energy spring mechanism

The drive concept of the 3AP circuit breaker family is based on the patented stored-energy spring principle. The mechanism types differ in terms of the number, size and arrangement of the opening and closing springs. Both the opening and closing springs are located inside the operating mechanism, thereby achieving a simple and sturdy device. Proven design principles such as vibration-isolated latches and load-free isolation of the charging mechanism were retained. 

 

Advantages of the stored-energy spring mechanism:

  • Same principle for rated voltages from 72.5 kV up to 800 kV
  • High reliability thanks to low operating energy (10,000 operating cycles guaranteed)
  • Reliable, economical and durable due to uncomplicated and robust construction with few moving parts
  • Controllable switching state at all times
  • Easy access to springs as they are not integrated in SF6 compartments
  • Maintenance-free for 25 years or 6,000 operation cycles
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1. Hydraulic storage cylinder; 2. Operating piston; 3. Pilot valve; 4. Main valve; 5. Closing solenoid; 6. Opening solenoid; 7. Oil tank; 8. Oil pump; 9. Motor; 10. Filter; 11. Non-return valve; 12. Pressure compensating valve; 13. Safety valve; 14. Pressure gauge; 15. Pressure monitor; 16. Compact hydraulic operating mechanism

Electrohydraulic operating mechanism

The electrohydraulic operating mechanism has been used in 3AT and 3AQ circuit breakers for more than 20 years. Even the highest switching voltages are safely brought under control in the shortest possible time, and it is also possible to master the most difficult switching tasks.

 

Advantages of the electrohydraulic operating mechanism:

  • High operating energy for the highest switching performance in the shortest possible time
  • Contact positions are reliably maintained even if the auxiliary power supply fails
  • Multiple reclosure possible without the need for recharging
  • Constant self-monitoring
  • Checking of energy reserves at any time
  • Low-maintenance, economical and long service life
  • Meets stringent environmental protection requirements

 

Composite insulators

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Areas of application:

  • Bushings for transformers and other devices
  • Grading capacitors
  • Voltage and current transformers
  • Cable connections
  • Surge arresters
  • Circuit breakers

 

Characteristics of composite insulators:

  • Low risk of breakage due to flexible sheds
  • Easy installation
  • Lightweight
  • Safety in the event of short circuits and earthquakes
  • No cleaning of silicone housing necessary
  • Resistant to environmental influences and pollution
  • Decades of operational experience with long-rod insulators,  surge arresters and circuit breakers

 

 

Quality management

Global production network

Our global production network ensures that we are always reachable and close to our customers. This reduces transportation costs and delivery times, and also improves our carbon footprint.

Global service

As a leader in the global market, we offer circuit breakers that meet the differing environmental, technical and economic conditions of countries around the world.

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countries around the world use Siemens circuit breakers

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circuit breakers in operation

Downloads, support and services

Our services for you

You can find informational materials on our circuit breakers and details about our services here.

We can gladly help you with installation, commissioning, diagnostics and malfunctions

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Testing laboratories at Schaltwerk Berlin

We test components at our accredited testing laboratories.
Testing laboratories at Schaltwerk Berlin
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Technical simulations

Numerical simulation and analytical calculation methods for efficient product development.

Technical simulations

More information

Proven expertise and top quality

Siemens circuit breakers deliver customized solutions, the latest technologies and decades of development experience from a single source. Do you have any questions? Are you looking for more information about our circuit breakers? We have experts to assist you with any issue.