What voltages are classified as EHV?

The classification of voltages is crucial in the field of electrical power systems, particularly concerning the design, operation, and safety of transmission lines. Extra High Voltage (EHV) typically refers to voltage levels that are 345 kV or above. This classification is made by several organizations and standards, including the Institute of Electrical and Electronics Engineers (IEEE) and the National Electric Safety Code (NESC).

EHV systems play a significant role in the transmission of electricity over long distances, as they facilitate lower line losses and the ability to transmit large amounts of power efficiently. Transmission lines operating at these voltage levels are designed to handle extreme electrical stress and require special insulation, equipment, and maintenance practices to ensure safety and reliability.

The other voltage thresholds listed in the options are classified under different categories, such as High Voltage (typically 100 kV to 345 kV) and Medium Voltage (up to 100 kV). Understanding these distinctions is essential for linemen and other professionals in the electrical industry to ensure proper handling, maintenance, and safety protocols are followed according to the voltage classification.