The standard, titled " IEC Standard Voltages ", is the definitive international reference for nominal electricity supply voltages. Developed by the International Electrotechnical Commission (IEC) , it establishes preferential values for both AC and DC systems to ensure global interoperability and safety. Core Objectives of IEC 60038 The standard serves two primary functions:

The standard organizes voltage levels into several "bands" or categories to address different industrial and residential needs:

: The primary standard is 230/400 V . This was harmonized from older 220/380 V and 240/415 V systems, a transition completed in most of Europe by 2003.

: It defines the maximum, nominal, and minimum reference values that equipment and system manufacturers must use during the design and testing phases. Standard Voltage Classifications

Specific standards for railway and public transport electrification:

: Includes a variety of North American and international standards, such as 120/208 V , 120/240 V (split-phase), and 277/480 V . High Power Industrial : Uses 400/690 V and up to 1,000 V. 2. Traction Systems (AC and DC)