3AP dead tank circuit breaker - the well grounded
For applications from 72.5 kV up to 550 kV
In contrast to live tank circuit breakers, dead tanks have a metal-enclosed interrupter unit, and the housing is always grounded. Therefore they are called dead tank circuit breakers. For certain substation designs, dead tank circuit breakers might be required instead of the standard live tank breakers. The dead tank breaker offers particular advantages if the protection design requires the use of several current transformers per pole assembly.
Most important characteristics of a dead tank breaker:
l Toroidal-core current transformers on bushings (compact construction)
l High short-circuit breaking currents possible (up to 63 kA with one interrupter unit)
l No creepage path across interrupter unit
l Low impulse load of the bases
l Low center of gravity of the bases (higher seismic withstand capability)
l Heating system available for low temperature applications
l Gas-insulated components ensure highest availability at minimum maintenance effort
l Metal-enclosed interrupter unit (grounded housing)
Current Transformers
The dead tank circuit breakers can be equipped with bushing current transformers for measurement or protection purposes, fulfilling the requirements according to international standards such as IEC, ANSI, etc.
The current transformers are mounted in weatherproof housings on both sides of each breaker pole and are located at the base of the bushings.The current trans-former leads terminate in the control cubicle at short- circuiting type terminal blocks. Our standard housing provides space for up to three current transformers per bushing.
Another of its strengths
The 3AP DT high-voltage circuit breaker operates safely and is capable of bearing high loads. Extra-strong porcelain bushings and an optimized circuit breaker design give it a very high seismic stability while in operation. The circuit breaker covers the whole temperature range from
-55 °C up to 50 °C with pure SF6, which makes it applicable for all climate zones.
Like the other circuit breakers, our dead tanks are based on our proven modular design using a patented self-compression arc-quenching system and the stored-energy spring drive mechanism. They assure consistent quenching performance with rated and short-circuit currents –even after many switching operations.
