Amendment 1 - IEC standard voltages

This document serves as an amendment to a foundational international specification regarding nominal voltages for electrical power transmission and distribution systems. Issued by the International Electrotechnical Commission, this particular update modifies the original edition established in 1975. It introduces necessary adjustments to voltage levels and tolerances to accommodate evolving technical requirements and ensure global interoperability among electrical equipment. The text outlines specific changes to the numerical values and classification criteria previously defined in the main standard. These modifications are intended to refine the existing framework without altering the core principles of the original publication. The content focuses exclusively on the updated parameters and the specific voltage systems affected by this change. It provides clarity for manufacturers, utilities, and regulatory bodies regarding the correct application of standard voltage values in international contexts. The amendment is structured to be read in conjunction with the base document, ensuring that all referenced tables and figures reflect the most current agreed-upon values for alternating and direct current systems at the time of its publication. This technical note facilitates seamless implementation across different national grids while maintaining consistency with international norms.