Only the parameters inside the frame (Sub-)Conductor are defined for sub-conductor. All other parameters (e.g. rated current) are specified per bundle. The tower type only specifies overhead line configurations, no concrete line couplings. For specifying the physical coupling of lines, you must use the corresponding element (ElmTow, Line couplings). You can create such an element in the Grid-Folder by clicking on the icon New object. Then select Others and set the Filter to Net Elements (Elm*). Then type ElmTow in the input field Element. You can then define the tower type and select the lines hanging on each position of a tower. This definition overrules the type definition of each individual line. You should use the DC resistance at the operating temperature. There is no temperature dependent formula implemented.