Recent questions tagged high-voltage

Description : How standard lightning impulse wave is represented?

Last Answer : Answer: Standard Lighting impulse wave is represented by 1.2/50 micro sec wave

Description : What is meant by voltage surge?

Last Answer : Voltage surge is sudden excessive rise in voltage that may be dangerous to the electrical equipment of an installation. Voltage surge cause damage to insulation of the system. Voltage surges are caused because of lightning, switching on and off the load at high voltages

Description : What is meant by impulse ratio of any lightning arrester?

Last Answer : Impulse ratio of any lightning arrester is the ratio of breakdown voltage of the wave of special duration to breakdown voltage of a 50Hz wave

Description : What is meant by Lightning arrester or surge diverter?

Last Answer : A Surge Diverter is a device that is connected between line and earth, i.e, in parallel with the equipment under protection at the substation. It limits the duration and amplitude of the follow current

Description : What is the difference between the lightning arrester and surge absorber?

Last Answer : Lightning arrester limits the duration and amplitude of the follow current while a surge absorber reduces the steepness of the wave front for a particular surge

Description : What is meant by protective angle? Give its value for reliable operation?

Last Answer : Protective angle is the vertical angle through the ground wire axis and the line passing from the ground wire axis to the outermost phase conductor. Its value for reliable protection is taken equal to 20-30 degrees

Description : Why Earth Wire is provided in the overhead transmission lines?

Last Answer : Earth wire is provided above the overhead transmission lines for protection against lightning strokes. The ground wire or earth wire protects the phase conductors or line conductors by attracting itself the ... traveling waves set in the lines by acting a short circuit secondary of the line current