NEW LIGHTNING-SURGE TEST METHOD FOR SUBSCRIBER TELECOMMUNICATION EQUIPMENT CONSIDERING NEARBY LIGHTNING RETURN STROKES

It has become very important to study the lightning surges that were i nduced in subscriber telecommunication equipment because of the increa se of susceptible circuits to the over voltage. The test generator is desire to be developed evaluating the resistibility of equipments agai nst lightning surges. This paper proposes a new lightning-test method for subscriber telecommunication equipment. The waveform of the test g enerator simulates that of the induced lightning surge voltage caused by a nearby return stroke. The output impedance of the surge generator is determined to match the common-mode impedance of telecommunication lines. The damaged condition of circuit parts and the trouble occurre nce rate estimated by using this method agree well with actual observa tions.