"4 kV" refers to a voltage level of 4 kilovolts, which is equivalent to 4,000 volts. This measurement is commonly used in electrical engineering and power distribution systems. Voltages at this level can be found in various applications, including industrial machinery and electrical substations, where high voltage is necessary for efficient power transmission. In electrical systems, kilovolts are often used to describe the voltage of transmission lines and equipment. Operating at 4 kV can pose safety risks, so proper insulation and protective equipment are essential to prevent electrical hazards. Understanding voltage levels like 4 kV is crucial for engineers and technicians working with high-voltage systems.