In this tutorial you will learn how measure the clearance of power lines in your design under different environmental conditions.  This tutorial assumes you have completed and understood Tutorials 1, 2, 3 and 4. If you have not, it is highly recommended you do so before starting this tutorial. At the end of this tutorial you will be able to:

  • setup different ground clearance heights,
  • model conductor sag under different environmental conditions,
  • measure the 3D clearance between any pair of conductor spans.

Ground Clearance Height

Probably the most important aspect of any design is making sure the conductors do not sag below a certain ground clearance height. If a conductor sags too low, either its tension must be increased, or its supporting poles moves closer together. Power Lines Pro allows easy visualisation of ground clearance lines in the Profile View. This is a blue dashed line drawn above the ground line in the Profile View, annotated with the ground clearance height for that line (initially we set the default clearance height to 5.5m). The ground clearance line and height are annotated in the below image:

You can change the height of the ground clearance line by opening the Clearances section in the top menu bar:

In addition to changing the height of the standard ground clearance line, you can also add new ground clearance lines, each with their own height. You do this by pressing the Add Clearance Line button the the Clearances section. This will add a new clearance line entry to your design. Here is an example of adding two extra clearance heights:

Modelling Different Environment Conditions

Typically you will want to make sure the conductor sag has sufficient ground clearance under different environmental parameters. Power Lines Pro can model conductor sag under different temperatures, wind pressures, ice conditions and allows users to apply a creep offset. In the Profile View, you may have already noticed that each conductor span is rendered as a solid line, but also there are dashed lines. These dashed lines are the conductor models under different environment conditions. The solid line represents the conductor model under the Primary Environment conditions. You can view, edit, and add new environment parameters in the Environments section in the top menu. This should looks something like this:

Measuring Ground Clearance

The ground clearance line, discussed above, is a useful visual tool to determine if any of the conductors sag too low to the ground. However, sometimes you may need to know the exact distance between a conductor and the ground. The Ground Clearance Measure Tool  can be used for this purpose. Select this tool and hover the mouse over the target conductor at the point you want to measure the ground clearance. In the Perspective and Profile Views you will notice a purple line extending from the conductor to the ground, annotated with the clearance height of the conductor at that point. The displayed clearance height is displayed for the lowest hanging environment parameter scenario (eg: hot).

In addition to this, in the top of the right hand menu you will see the detailed ground clearance information for the hovered conductor. This will include the ground clearance at that point for every environment scenario. This will look something like this:

Measuring Inter-Conductor Clearance

In some designs you may need to measure the minimum distance between two conductors. An example of this is if you have a conductor span passing above another conductor. An example of this scenario is shown below:

In this scenario, you may want to make sure that, for example, the higher conductor when "hot" does not get too close to the lower conductor when it is "cold". Power Lines Pro allows you to find the minimum distance between any two pairs of conductor spans, under any environmental conditions. You can do this using the Conductor Clearance Measure Tool  

When you select this tool, the Plan and Profile Views will be hidden, and you will only be shown the Perspective View. Additionally, the Perspective View will now show, using dashed lines, the conductor models for all environment scenarios. To use the tool, left-click on the two conductor spans that you want to measure the distance between. They will become highlighted in red when you do this. A purple line will be drawn at the closest approach between the two clicked conductor spans. The minimum clearance information will be displayed at the top of the right hand menu. You should see something like this:

This completes this tutorial. We really value your feedback, queries, suggestions, send them all our way!