The amount of sag depends on the stiffness of the busbar. If the busbar's diameter and wall thickness are determined, the sag under normal operating conditions can be determined. One side of the bend may be a little thinner but the other side will be a little thicker. Bill. Design of busbars and connections in air insulated substation This chapter focusses on the design implications of connecting or rigid, single or bundled conductors to HV equipment with connectors/clamps, either bolted, welded or compressed. Of importance are equipment and component mechanical and. For the upper tier, providing communication between cells, used flexible busbars. com/2018/09/electric-substation-now-online •Conductors.