6.20. Rights of way for transmission circuits arc difficult to obtain in urban areas, and existing lines arc often upgraded by reconductoring the line with larger conductors or by reinsulating

the line for operation at higher voltage. Thermal considerations and maximum power which the line can transmit are the important considerations.A 138-kV line is 50 km long and is composed of Partridge conductors with flat horizontal spacing of 5 m between adjacent conductors. Neglect resistance and find