voltagelevel

Voltage level is a basic parameter in electrical engineering that describes the potential difference between two points in a circuit and the nominal operating voltage used to characterize electrical equipment and systems. In power engineering, voltage level is used to classify transmission and distribution networks and to specify insulation, clearances, and equipment ratings. Common classifications include low voltage (typically up to 1 kV), medium voltage (1–35 kV), high voltage (roughly 35–230 kV), and extra-high voltage (above 230 kV). These categories are not universal; definitions vary by country and standardization body. For example, household supply voltages differ by region (about 120 V in North America and about 230 V in many parts of Europe), while industrial and transmission voltages are often much higher, such as 110 kV, 220 kV, or higher.

Voltage levels arise from system design: generation determines the initial voltage, and transformers step voltage up or down for efficient transmission and safe distribution. Insulation coordination and equipment ratings—for cables, switchgear, and insulation levels—depend on the selected voltage level and the expected crest or peak voltages. Measuring voltage levels uses instruments such as voltmeters and multimeters and is central to operation, protection, and maintenance.

In planning and operation, the choice of voltage level affects losses, equipment cost, safety, and reliability. The concept applies to both AC and DC systems and extends to electronics and telecommunications, where nominal operating voltages define design rules.