Professional Answer: While often confused, disruptive critical voltage (Vc) and visual critical voltage (Vv) refer to two distinct stages of the corona effect.

• Disruptive Critical Voltage (Vc): The theoretical minimum voltage at which the ionization of air begins near the conductor surface. At this stage, the corona is not yet visually apparent, but can be detected by a hissing sound and ozone production.

• Visual Critical Voltage (Vv): The slightly higher voltage at which the corona becomes visible as a faint, uniform glow along the length of the conductor. The visual effect requires a higher level of ionization and energy, which is why it occurs at a voltage greater than Vc.

To minimize corona effects, our high-quality stringing equipment and tools are designed to facilitate the installation of conductors that optimize spacing and tension, thereby helping to maintain the line's operating voltage below its critical thresholds.