# IEC 60038

International Standard IEC 60038:1983 defines a set of standard voltages for use in low voltage and high voltage AC electricity supply systems.

IEC voltage range AC RMS
voltage
(V)
DC voltage (V) Defining risk
High voltage> 1 000> 1 500Electrical arcing
Low voltage50 to 1 000120 to 1 500Electrical shock
Extra-low voltage< 50< 120Low risk

## 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

YearNeutral-Phase [V] / Phase-Phase [V]
1987220 V / 380 V– 10% .. +10% [1]
1988 2003230 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.