Wind Span
Theory - Wind Spans
The Wind Span is used to calculate the force applied to the conductors that is transferred to the pole. The Wind Span is defined as the sum of half the span length of the adjacent spans on a pole. Wind spans are independent of the weather conditions.
For Example. Consider the scenario in Figure 1 where Pole 2 has a span of 200m to the left and 150m to the right. The Wind Span for Pole 2 would be 200/2 + 150/2 = 175m.
Figure 1: Wind Span Example
Neara Model - Wind Spans
To access the Wind Spans within Neara create a custom report and select Assembies -> SectionAttachments.
For help creating custom reports see How To Create Custom Reports.
Weight Span
Theory - Weight Spans
The concept of a weight span is the vertical force on an insulator in terms of conductor length (rather than as a force). For example if the weight span was calculated to be 100m of Lemon conductor then this would be equivalent to to saying the load on the insulator is the same as 100m of Lemon conductor hanging down vertically under the insulator. To calculate the force in this example we would look up the Lemon conductor weight per distance from a data sheet which is 973kg/km. Hence the force would be 100m x 973kg/km x 1km / 1000m x 9.81N/kg = 954.5N. Hence a 100m weight span is equivalent to 954.5N of vertical force on the insulator.
Excerpt from Nexans Olex Aerial Catalogue
Weight spans can be both positive and negative. A positive weight span means there is weight on the insulator and a negative weight span means the insulator is in uplift. Typical ways to solve uplift problems are installing a termination structure or installing counterweights. Note that the weight span is dependant on the conductor tension and hence is dependant on the weather case.
The formula used to calculate the weight span span is:
See AS/NZS 7000:2016 equation R22 and R23 for more details.
Neara Model - Weight Spans
To access the Weight Spans within Neara create a custom report and select Assemblies -> SectionAttachments -> CableAttachments -> Environents
For help creating custom reports see How To Create Custom Reports.