Boosting voltage By helpmeuu 1898 The commencement of the electricity business Hanseong Electric company Corporation 1962 Economic Development Plan 1965 Electrification Project in Rural Areas 1967 A Committee for the promotion of Pressure 1971 Boosting approval 1972 Start new demand availability 1973 Initiation of existing demand availability 1977 110/220 V Combined Devices 1978 Prohibition of production of 110V device 1978 Mandatory leakage circuit breaker 1991 Change the standard voltage 1992 Unification for new demand 1993 Prohibition of production of the whole 110V device 1999 Achieve boosting voltage 2005 Complete boosting voltage business