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Product overview

Overview of our dead tank circuit breakers

We deliver 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. The interrupter unit in this technology is located in a grounded metal-enclosed housing.

Main features:

  • Toroidal-core current transformers on bushings (compact construction)
  • High short-circuit breaking currents possible (up to 90 kA with one interrupter unit)
  • Low center of gravity of the bases (higher seismic withstand capability)
  • Gas-insulated components ensure highest availability with minimum maintenance effort
  • Metal-enclosed interrupter unit (grounded housing)
  • Available with porcelain or composite insulators
  • Suitable for temperatures from -60 to 55°C with mixed gas solutions or various heating systems
  • High seismic safety up to 0.5 g
  • 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, maintenance, training and technical advice from a single source
  • Guaranteed availability of spare parts for all Siemens circuit breakers for a minimum of 25 years after delivery

Our dead tank product family


3AP dead tank circuit breakers

Our 3AP 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. 3AP1DT circuit breakers up to 362 kV are equipped with one interrupter unit per pole. 3AP1DT circuit breakers up to 362 kV are equipped with one interrupter unit per pole.

3AP2DT circuit breakers for applications up to 550 kV include 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 for applications from 362 kV to 550 kV (3AP3). 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 (FG), for single-pole operation also with a common base (FE) or for single-pole operation with separate bases (FI).

Technical data

All values in accordance with IEC, other values on request. / *Limited normal current ratings at more than +40°C.