Problem description:

Three phases system busbar type HOI - 12/7.Conductors are copper's tubes.
Inside and outside the tubes is air.The three conductors are surrounded by
the shield.


    Voltage conductors:
                       Ur = 9,8 kV
                       Us = -4,9kV
                       Ut = -4,9kV
   
    Dimensions:

    Cable diameter = 305 mm
    Inner conductor diameter = 65 mm
    Outer conductor diameter = 70 mm
    
    Distance from center of cable to center of conductor shield= 90 mm
    
    Conductor's material - copper
    

    Electric permittivity of conductor  = 1
    Electric permittivity of air = 1
