Searching method of grounding route in buildings using amplitude and phase

Grounding systems must be maintained to protect equipment from lightning surges and other unintentional overvoltages occurring over power lines. However, in many cases it is difficult to maintain a reliability grounding system because unintended connections are sometimes made when connecting telecommunication lines between equipment, or when a cabinet accidentally comes into contact with the metal framework of the building. This paper describes a method of searching for the grounding route by using both amplitude and phase. The phase reference is also obtained from the injected signal, whose frequency is ten times that of the searching signal, so as to remove the reference line. The results indicate that this method can detect whether the observation point is connected directly or indirectly to the injection point.