Analysis of Tower Stringset Replacement from 33 kV to 66 kV Considering Sagging Clearance

Authors

• Muhammad Lazuardi Azzura, Department of Metallurgical and Materials Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, West Java 16424, IndonesiaFollow
• Anne Zulfia Syahrial, Department of Metallurgical and Materials Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, West Java 16424, IndonesiaFollow
• Julius Purnama Eka Kartika, Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Kampus UI Depok, West Java 16424, IndonesiaFollow

Abstract

Efforts to increase the capacity of transmission networks are often undertaken by uprating the operating voltage of existing lines rather than building entirely new infrastructure. Such uprating typically involves the replacement of tower insulator stringsets to withstand higher voltages, while also ensuring that mechanical performance remains adequate. This paper presents an analysis of uprating the Parakan–Sunyaragi transmission line from 33 kV to 66 kV, with particular emphasis on conductor sagging and the resulting clearance from the ground. The methodology employed includes calculations based on catenary equations, analysis of conductor tensile forces, and a comparative evaluation of two widely used insulator types, namely cap & pin and long rod. The findings demonstrate that, under the planned uprating, conductor sagging still remains within operationally safe limits, providing a clearance greater than 8 m from the ground. Although both types of insulators meet the required safety margins, long rod insulators gives better performance and more stable sagging characteristics, greater resistance to contamination, and longer service life. These findings indicate that upgrading to 66 kV is technically safe, as long as proper tensioning is applied during installation and regular field inspections are maintained.

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Recommended Citation

Azzura, Muhammad Lazuardi; Syahrial, Anne Zulfia; and Kartika, Julius Purnama Eka (2026) "Analysis of Tower Stringset Replacement from 33 kV to 66 kV Considering Sagging Clearance," Journal of Materials Exploration and Findings: Vol. 5: Iss. 2, Article 5.
DOI: 10.7454/jmef.v5i2.1128
Available at: https://scholarhub.ui.ac.id/jmef/vol5/iss2/5