HD 472 S1:1989

Nominal voltages for low-voltage public electricity supply systems

Scope

Applies to: a.c. transmission, distribution and utilization systems and equipment with standard frequencies 50 Hz and 60 Hz and a nominal voltage above 100 V; a.c. and d.c. traction systems; a.c. and d.c. equipment with nominal voltages below 120 V a.c. or below 750 V d.c.