3AT live tank circuit breaker - the power pack
Electrohydraulically operating circuit breaker for applications from 245 kV up to 800 kV
In contrast to our 3AP series, 3AT circuit breakers are equipped with a hydraulic operating mechanism. Just like all of our circuit breaker types, it provides a high operating energy which safely controls even the highest switching voltages. It can master the most difficult switching duties such as breaking short-circuit currents in the shortest possible time. Its switching performance and the design of its interrupter unit make it eminently suited for generator applications.
Constant availability assured
Further significant advantages are the reliability and the extremely rugged design of 3AT high-voltage circuit breakers. Solid porcelain for the insulators and breaker bases optimized by means of the most up-to-date computing techniques provide this circuit breaker with an excellent seismic loading capacity.
With additional earthquake damping equipment from Siemens, it is unshakable in almost any location.
The switching mechanism in the interrupter unit is operated via the hydraulic operating mechanism. Also, the cur-rent interruption differs from 3AP circuit breakers. The 3AT interrupter unit uses the tried-and-tested double-nozzle quenching system. A contact system with graphite double nozzles ensures a constant quenching response and like-wise constant electric strength. The high-performance double nozzles are resistant to erosion and have a long service life.
Further advantages of this quenching technique include the minimal pressure rise during the quenching process and the minimal conductivity of the arc plasma. The double-nozzle system is even suitable for special applications such as restrike-free interruption of low inductive and capacitive currents as well as interruption of all types of short-circuits.
