E485-S Emirel Overvoltage protection

FUNCTION AND USE The overvoltages are considered among the causes generating damages and breakdowns to the electric and electronic equipments. The overvoltages can “enter” into the equipment through the main net or through the sensors lines that is at high or low voltage. They are generally due to atmospheric events, but they can also be generated by wrong operations on line etc. The overvoltages danger is given by the fact that their amplitude can reach also several kV and the leading edge is very sharp (in the order of ms), but it is not repetitive. For limiting the effects of the overvoltages it is required a device “cutting” the voltage down to such a value to protect the equipment and to dissipate the energy associated with the overvoltage. Due to the sharp leading edge, the protection device must have a sparkover time shorter than the rising time of the overvoltage to be cut. The device E 485-S is made by a combination (Fig.1) of “gas dischargers” and “varistors” and it is used for protecting equipments that could be damaged by overvoltage spikes with high energy, such as: atmospheric disturbances, wrong operation on high voltage line, lighting etc.