RECOMMENDED SELECTION OF TOWERS

Most common structures and cross sections for non-insulated conductors in different climate conditions

The application tables define the recommended types of towers and appropriate purpose of the tower in the route, for certain conductor cross sections and specific max. working stress, conventional shapes of tower head type and when used in different climate conditions,. For suspension towers the allowed wind span is stated (semi-sum of the adjacent spans), as also for the tension towers the allowed route deviation angle is present. Towers are selected based on the most appropriate wind span relevant for the construction of the tower, and the allowed electric span.

Electric spans defined in tables refer to use of post type isolators (string 0.00m), on the adjacent towers with equal spans of conductor suspension i.e. equal tower head type. Actual electric spans should be precisely defined and controlled depending on the suspension equipment and head forms of adjacent towers.

The working stress of conductors does not influence the admissible wind spans for suspension tower structures. Still it conditions the required tower height (influence on the conductor sag) and the possibility of using the tower in case of exceptional load (influence on the breaking strength). The allowed wind spans stated for conductor suspension sets are equal for a specific tower head type, conductor cross section and basic wind load without regard to the quantity of the conductor working stress.

The allowed sum of vertical forces relates to vertical load of conductors and suspension equipment and electrical devices (disconnectors, etc.) placed on the tower.

ISO 14001 ISO 9001 OHSAS 18000