International Standard IEC 60038:1983 defines a set of standard voltages for use in low voltage and high voltage AC and DC electricity supply systems.
Where two voltages are given below separated by “/”, the first is the root-mean-square voltage between a phase and the neutral connector, whereas the second is the corresponding root-mean-square voltage between two phases (exception: the category shown below called “One Phase”, where 240 V is the root-mean-square voltage between the two legs of a split phase). The three-phase voltages are for use in either four-wire (with neutral) or three-wire (without neutral) systems.
Three-phase 50 Hz
• 230 V / 400 V (formerly 220/380 V)
• 400 V / 690 V (formerly 380/660 V)
• 1000 V phase to phase (3 wire)
Suppliers using 220 V / 380 V or 240 V / 415 V systems were expected by the standard to migrate to the recommended value of 230 V / 400 V by the year 2003. This migration has already been largely completed, at least within the European Union.
Voltage conversion schedule
Three-phase 60 Hz
• 120 V / 208 V
• 240 V
• 277 V / 480 V
• 480 V
• 347 V / 600 V
• 600 V / 1000 V
One-phase, three-wire 60 Hz (American split-phase)
120 V / 240 V
As per International Standard IEC 60038:1983, nominal voltages are above 1 kV and not exceeding 35 kV.
There are two series, one from 3 kV up to 35 kV and another one from 4.16 kV up to 34.5 kV.
As per International Standard IEC 60038:1983, nominal voltages are above 35 kV and not exceeding 230 kV.
As per International Standard IEC 60038:1983, the highest voltage for equipment is the characteristic value exceeding 245 kV. The enumeration begins at 300 kV and ends with 1200 kV.