European lightning arrester is connected between the cable and the earth, usually in parallel with the protected equipment. The arrester can effectively protect the communication equipment. Once there is abnormal voltage, the arrester will act and play a protective role. When the communication cable or equipment is running under the normal working voltage, the arrester will not work, which is regarded as open circuit to the ground. Once the high voltage occurs and the insulation of the protected equipment is endangered, the arrester will act immediately to direct the high voltage impulse current to the earth, so as to limit the voltage amplitude and protect the insulation of communication cables and equipment. When the over-voltage disappears, the arrester quickly returns to its original state and makes the communication line work normally.
Therefore, the main function of the arrester is to cut the amplitude of the inrush current wave through the action of parallel discharge gap or nonlinear resistance, so as to reduce the voltage value of the protected equipment, so as to protect the communication lines and equipment.
European lightning arrester is not only used to protect all kinds of electrical equipment in power system from high voltage caused by lightning, but also used to protect high voltage operation.