Jurnal Sains, Teknologi dan Industri, Vol. 12, No.2, Juni 2015, pp.292 - 299 ISSN 1693-2390 print/ISSN 2407-0939 online Copyright © 2015, SITEKIN, ISSN 2407-0939 292 Analisis Sistem PentanahanTransformator Distribusi Di Universitas Lancang Kuning Pekanbaru Abrar Tanjung Jurusan Teknik Elektro, Fakultas Teknik, Universitas Lancang Kuning Jl. Yos Sudarso Km. 8 Rumbai Pekanbaru, Telp. (0761) 52324 E-mail : abrartanjung_1970@yahoo.co.id (Received: 27 Maret 2015; Revised: 16 Juni 2015; Accepted: 27 Juni 2015) ABSTRAK Untuk menyalurkan kebutuhan tenaga listrik tersebut dari produsen listrik ke konsumen diperlukan suatu jaringan dan gardu distribusi. Berdasarkan Standar Perusahaan Listrik Negara (SPLN), sistem dapat dikatakan efektif bila drop tegangannya tidak melebihi + 5 % dan - 10 % dari tegangan nominal, rugi-rugi daya dan dari total daya yang disalurkan. Pada saat terjadi gangguan, arus gangguan yang dialirkan ke tanah akan menimbulkan perbedaan tegangan pada permukaan tanah yang disebabkan karena adanya tahanan tanah.Universitas Lancang Kuning merupakan lembaga pendidikan memiliki beberapa fakultas mempunyai kegiatan admistrasi dan belajar mengajar, menggunakan peralatan listrik. Pemakaian beban listrik juga banyak dipakai dalam pemasangan lampu penerangan dan peralatan-peralatan listrik lainnya. Akibat penambahan beban pada gedung fakultas Unilak, menyebabkan terjadi ketidakseimbangan beban, nilai tahanan pentanahan peralatan sangat besar dan terjadi kelebihan beban ( Over load) pada transformator distribusi. Tujuan Penelitian ini dilakukan untuk menganalisa dan menghitung besar tahanan pentanahan transformator distribusi di Universitas Lancang Kuning. Metode penelitian dengan cara melakukan pengukuran data transfromator distribusi menggunakan alat ukur, melakukan analisa data dan perhitungan data. Berdasarkan hasil perhitungan nilai pentanahan peralatan transformator distribusi diperoleh sebesar 22,15 ohm, arus gangguan hubung singkat pada transformator distribusi 1,15 amper, kenaikan tegangan phasa sehat diperoleh untuk transformator distribusi sebesar 308 volt, tegangan sentuh 288,1 volt dan tegangan langkah sebesar 938 volt, rugi-rugi daya akibat arus netral sebesar 111,62 watt. Kata Kunci : pentanahan netral, sistem tenaga listrik. transformator distribusi ABSTRACT To distribute the electrical power needs of electricity producers to consumers required a distribution network and substations. Based on the Standard of the State Electricity Company (SPLN), the system can be said to be effective if the voltage drop does not exceed + 5% and - 10% of the nominal voltage, and power losses of the total power supplied. In the event of disruption, interference currents that flowed into the ground will cause the voltage difference on the ground level due to the detainee soil. Lancang Kuning University is an educational institution has several administration and faculty have teaching and learning activities, using electrical equipment. The use of electrical load is also widely used in the installation of lighting and other electrical equipment. The effect of addition load on Unilak faculty building, can be effect unbalance load, grounding resistance equipment will be rised and made overload in distribution transformers. The purpose of this research was to analyze and calculate the distribution transformer earthing prisoners in Lancang Kuning University. Research methods in a way distribution transfromator measurement data using a measuring instrument, perform data analysis and calculation of data. Based on the results of the calculation value the distribution transformer earthing equipment obtained for 22.15 ohm, short-circuit fault current at the distribution transformer 1.15 amperes, rising a healthy phase voltage acquired for distribution transformers of 308 volts, the voltage of 288.1 volts touch and step voltages for 938 volt, the impact neutral currents of power losses at 111.62 watts. Keywords: distribution transformers, neutral grounding, electrical power system