Lightning Protection of Power Equipment for Telecommunications

Power equipment for telecommunications which uses commercial power as its input source, is easily damaged by lightning from commercial power distribution lines. The stations which have antenna towers such as microwave relay stations, are often damaged by direct lightning strike surge. Consequently, lightning protection for power equipment in order to maintain its reliability. NTT has therefore investigated the actual conditions of an invading lightning surge, the grounding impedance, lightning damage, etc., about microwave relay stations and small scale telephone offices which are often damaged by an invading lightning surge. NTT further has examined systematic lightning protections of telecommunication power equipment. As a result, it was found that enlargement of arrester capacity, multi-installation of arresters and grounding surge impedance reduction by using interconnected grounding and by improving the technique for laying grounding wire, etc., are effective against lightning surge.