No. 1107
	Current situation of Technology and Problem on Utility Pole Eliminating Program
	A committee specialized in investigation of " technology and problem on Utility Pole Eliminating Program "
	Keyword : Underground distribution system, Maintenance policy, Construction technique, Utility pole, Manufacturer, Utility pole eliminate
	Overhead line and underground system are applied as usual distribution system in electric power companies and in telecommunication companies in Japan. Generally, project of rebuilding overhead line to underground system is defined as Utility Pole Eliminating Program. Conventionally, the area where underground distribution system was applied had been limited in only city center like Tokyo metropolitan in Japan. However, request for utility pole elimination has shown tendency of increase from viewpoint of city view and natural disaster. In 1986, the Ministry of Construction (today's Ministry of Land, Infrastructure and Transport) and utilities including electric power companies and telecommunication companies carried out first utility pole eliminating program in Japan. Technical issues including outside of Japan about underground distribution system would be found in "The technical trend of the underground distribution system" (the 343rd issue from Institute of Electrical Engineers of Japan ‡U part, 1990). After that, utility pole eliminating program have been proceeded steadily while purpose and methodology change in Japan. During that period, utilities and manufacturers have developed compact structure of underground cable and joint, and easy installation structure which avoid fault by mis-installation work of joint. In addition, various diagnosis technologies for underground system have been developed in same period. The purpose of this report is clarification of technical trend and problem of underground distribution system, underground cable, joint, maintenance policy and construction technique.
	©2007. The Institute of Electrical Engineers of Japan