Regarding to the development of industry in different fields, this kind of panels is so practical in oil, gas, petrochemical, steel, cement, mine, weaving, bus bar and converting industriesand etc. They are designed in a manner that each cell is composed of the modules with different altitudes. Their altitude differs between 100mm up to 700mm depending on the feeders' type. Each feeder has a separate case and it is impossible to draw out the module unless its door is open. Each module has three positions: insertion, test and disconnection. It is feasible to change the position of the similar modules with no interruption of the main bus .It means the main bus interruption is minimum. The technical features of these panels are as follows: