This standard specifies standard voltage values which are intended to serve:
——As preferred values for the nominal voltage of electrical supply systems, and;
——As reference values for equipment and system design.
This standard is applicable to:
——AC transmission, distribution and utilization systems and equipment for use in such systems with standard frequency 50Hz having a nominal voltage above 220V;
——AC and DC traction systems;
——Equipment with rated voltage below 120V and standard frequency 50Hz (not limited absolutely), and equipment with DC voltage below 1,500V. Such equipment covers batteries (from primary or secondary cells), other power supply devices (AC/DC), electrical equipment (including industrial and communication), and appliances.
——HVDC transmission system.
This standard is not applicable to voltages representing or transmitting signals or measured values.
This standard is not applicable to voltages of internal elements, components and parts used within electrical devices.
Note 1: AC voltage in this standard is the root mean square value and DC voltage is ripple-free DC voltage value.
Note 2: Test voltage, test condition and acceptance standard shall be specified in system and product standards.
2 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.
2.1
nominal system voltage
given value used for marking or identifying system voltage
