Design Ruling Span
The Design Ruling Span is the span length value used as the basis for the sag and tension computations of the conductor.
The values in the Design Ruling Span drop-down box are populated by reading unique values for the RULINGSPAN field in the MMENG_CONDTENSION table. When the user chooses a design ruling span from the list it is compared with the Actual Ruling Span calculated result.
Actual Ruling Span
The Actual Ruling Span is computed as the median length of a series of spans, and can be compared to the Design Ruling Span to ensure that the sag and tension values used for the conductor are representative of field conditions.
The following formula is used to calculate the Actual Ruling Span from user specified adjacent spans.
Sr = Ruling span
S(1..n) = Conductor span length between supports taken from the Spans Grid (see below).
If the calculated Actual Ruling Span varies from the specified Design Ruling Span by more than a user-specified percentage (Designer Options | Structural Analysis tab), the Actual Ruling Span result is shaded in red. If any of the individual spans fall outside a user-specified percentage (Designer Options | Structural Analysis tab), they are also shaded in red in the Spans Grid.
After the spans have been identified using the Span Length Tool, the grid will display a record for each conductor (present phases + neutral) at a given span. If there are any conductors selected when the Structural Analysis tool is initialized, those conductors will appear in the Spans Grid. Any span can be deleted by highlighting the span (all conductor records for the span will automatically highlight as well) and pressing the [DELETE] key.