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Modeling ADSS Cables in PLS-CADD and PLS-CADD/Lite

Modeling ADSS cables in PLS-CADD and PLS-CADD/Lite is quite simple. This TechNote discusses how to do so using data sheets commonly supplied by Alcoa Fujicura Ltd., or data supplied by other ADSS manufacturers.

The typical ADSS Specification will include the Cable Diameter, Cable Weight, Maximum Cable Rated Load (MRCL), Approximate Cable Breaking Strength, Coefficient of Linear Expansion, and the Initial, Final, and 10 Year Cable Modulus. These quantities are sufficient to model the ADSS in PLS-CADD and PLS-CADD/Lite. The section of the specification will typically be formatted as follows:

Typical ADSS Specifications

To input this data in PLS-CADD and/or PLS-CADD/Lite, click on the Sections / Edit Cable Data menu item. If you are creating a new cable file you will need to type in the desired name and path. Once this is done, you will be in the Cable Data dialog box where you can input the following information:

No other cable data values are required. Note that you may need to convert the units for the modulus and thermal expansion values. Once input, the data for our example specification would be as follows:

PLS-CADD Cable Data Dialog Box

The thermal rating properties are not required unless you will be using one of the thermal rating functions of PLS-CADD with the ADSS - this is highly unlikely.

That is all that is required to create a PLS-CADD ADSS cable file. You are now ready to use the ADSS on your PLS-CADD projects to not only develop stringing charts, but also to check clearances and loadings of the ADSS under various conditions. In addition, you can insure that your ADSS will not interfere with the significantly greater sag changes that your transmission and distribution conductors will experience with temperature changes and thereby prevent any clashing, or worse, wrapping, that you might experience in the field. With the communications industry "standard" of sagging in ADSS at 1% of the span length, these types of problems do occur quite frequently and should be carefully checked with a proper analysis.

As you can see from the above, the data that needs to be given to you are standard properties for any ADSS so there isn't any reason why your ADSS supplier cannot help you. If your manufacturer has any questions, please have them contact us. We will assist them in getting all of their cable data into a PLS-CADD ready format and we will even add them to our online library for all of their customers to download and use.

* Note: Some manufacturers may allow using the higher Cable Breaking Strength, or RBS, for the Ultimate Tension value.  When doing so, please note that the MRCL is usually less than the NESC recommended 60% tension limitation in Rule 261H.1.a, and your Criteria/Cable Tensions and Criteria/Automatic Sagging information should be modified accordingly.  Also note that you may have other design conditions such as a Heavy Ice that may result in a higher tension than the MRCL, so these cases must also be limited in the Criteria tables to insure that they are not exceeded.  It is simpler and safer to just use the MRCL for the Ultimate Tension value to insure that it is never exceeded.
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