Scientific paper ID 861 : 2013/3

The automatic breakers are protection devices, which through which break to current circuits at normal operational states. They can be classified in the different signs: the type of arc-stilling camera, in the way of the arc extinguishing, the type of the arc-stilling area and others.

Arc-stilling area (environment) identify the basic parameters of the device according to IEC in static and dynamic mode. These parameters can : internal isolation of the circuit breaker, distance between the electrodes, nominal frequency shutdown, drilling voltage between the electrodes in the off state, minimum leak current when switch the breaker turn off, time of reaction, rated voltage and rated current.

At present in the practice mainly using breakers with gas arc-stilling environment. These are air breakers with blowing of rainbow, vacuum breakers, gaz generates, circuit-gas, which is one of the most modern types of breakers for medium and high voltage.

Visualization and research the arc-stilling processes in different gas environments under laboratory conditions is necessary for updating and development of material and technical resources and training program on a range of school subjects for students in "Electric Power Supply and Electrical Equipment" (EE) at Todor Kableshkov University of Transport. This motivated the team of teachers and students from the school to design and create a stand for laboratory testing of these processes. This paper presents the conceptual project for the realization of the stand.