Dead tank circuit breakers

We offer dead tank circuit breakers for applications from 72.5 kV to 550 kV with a service life of up to 50 years. Our DT circuit breakers deliver the greatest possible reliability – even in extreme environmental conditions across the globe.
Features & advantages
- High short-circuit breaking currents possible (up to 90 kA with one interrupter unit)
- High seismic withstand capability up to 0.5 g
- Available with porcelain or composite insulators
- Temperatures from -60 to 55°C with mixed gas solutions or various heating systems
- Suitable for altitudes of up to 1,000 meters
- Gas leakage rate of less than 0.1 % per year
- Inspection after 12 and maintenance after 25 years
- 10,000 switching operations are guaranteed
- Product life time of up to 50 years
- Easy installation and commissioning: only few assemblies
- Installation, commissioning, service, training and technical advice from a single source
- Guaranteed spare parts for all circuit breakers for a minimum of 25 years after delivery

Breaking new ground for dead tank breakers
Siemens Energy completes type approval test of F-gas-free
123 kV Blue dead tank circuit breaker
The first 3AV1DT 123 kV vacuum dead tank breaker has passed the type tests for IEEE / ANSI markets and is now ready for its first pilot installation at a well-known energy supplier in California. With zero CO2 emissions the non-toxic insulating medium is as clean as the air that you breathe, and the proven vacuum switching technology offers highest switching performance without degradation!
Thus it helps our customers worldwide to achieve their goals for climate neutral and reliable power grids.
Our dead tank product family
3AV Blue dead tank up to 145 kV
Siemens Energy combines vacuum switching technology with clean air insulation that is capable of reliable short-circuit interruption at voltage levels from 72.5 - 145 kV with zero CO2 emissions over the lifetime of the equipment. This solution provides the best performance addressing the highest environmental standards in place now and ones in the future.
Advantages of vacuum switching technology:
- Zero greenhouse gases
- Greenhouse- and F-gas free insulation
- No CO2e emissions - Zero global warming potential (GWP)
- No F-gas regulated – reporting, training, frequent density checks
- Minimized gas handling during operation & end of life (no gas recycling) - Zero impact on environment, health & safety (EHS)
- No toxic insulation gas, no toxic decomposition products
- No special safety measures required - Full performance & reliability
- High number of short-circuit and rated current interruptions
- Two-cycle current interruption
- More than 10 years of experience in HV vacuum switching
- Lowest temperature applications without heating systems
Vacuum interrupting technology enables the implementation of clean air as an insulating medium in our Blue portfolio. Our clean air technology - 80% N2 and 20% O2, cleaned and free of humidity (synthetic air) - is the first F-gas-free insulation and represents an important step towards the company goal of developing completely environmentally friendly technologies.
Dead tank circuit breakers up to 550 kV
Our dead tank breaker family is available for applications from 72.5 kV up to 550 kV and for short-circuit interruption up to 90 kA. DT breakers up to 362 kV are equipped with one interrupter unit per pole, up to 550 kV with two interrupter units.
We provide dead tank circuit breakers with 2-cycle operation for applications up to 362 kV. The circuit breakers can be equipped with optional closing resistors or applications from 362 kV to 550 kV. Several current transformer solutions are at your disposal which can be realized according to your specific project requirements.
Our high-voltage dead tank circuit breakers are available for three-pole operation with a common base, for single-pole operation also with a common base or for single-pole operation with separate bases.
All values in accordance with IEC, other values on request.
*Limited normal current ratings at more than +40°C.