IEC voltage range AC RMS
voltage
(V)
DC voltage (V) Defining risk
High voltage > 1 000 > 1 500 Electrical arcing
Low voltage 50 to 1 000 120 to 1 500 Electrical shock
Extra-low voltage < 50 < 120 Low risk

International Standard IEC 60038, IEC standard voltages, defines a set of standard voltages for use in low voltage and high voltage AC and DC electricity supply systems.

Low voltage

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

Year Neutral-Phase [V] / Phase-Phase [V]
— 1987 220 V / 380 V – 10% .. +10% [1]
1988 — 2003 230 V / 400 V – 10% .. + 6% [1]
2003 — 230 V / 400 V – 10% .. +10% [1]

Three-phase 60 Hz

  • 120 V / 208 V
  • 240 V
  • 230 V / 400 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

Table 3 1kV to 35kV

Table 3 of IEC 60038 lists nominal voltages 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.

Table 4 35kV - 230kV

Table 4 shows nominal voltages above 35 kV and not exceeding 230 kV.

Table 5 245 - 1,200 kV

Table 5 is systematically different, as the highest voltage for equipment is the characteristic value exceeding 245 kV. The enumeration begins at 300 kV and ends with 1200 kV.

See also

References

External links