Environmental pollution due to the burning of rice husk biomass and discarded transformer oil has a negative impact on the environment and livings. Utilization of rice husk biomass apart from being used as animal feed, fertilizer, can also be used as a purification of used transformer oil so that used transformers that were originally going to become waste can be reused in a long period of time. This study aims to analyze the effectiveness of rice husk activated charcoal in improving the breakdown voltage of used nynas libra transformer oil. The activator material used in rice husk charcoal is NAOH 30% as much as 100 ml with a chemical method for the activation process. To obtain the effectiveness value in terms of the percentage increase in breakdown voltage before and after purification, then the value of the voltage of the two test treatments is also reviewed against the standard breakdown voltage of transformer oil SPLN 49-1. The results showed that the average breakdown voltage increase of 5 times in each process was 166.99%. It can be concluded that the use of rice husk activated charcoal as a purification agent is effective in improving the breakdown voltage of used transformer oil

Penelitian ini bertujuan untuk mengetahui karakteristik tegangan tembus dan sifat hidrofobik dari isolator resin epoksi dengan dan tanpa bahan pengisi abu arang tongkol jagung. Penambahan bahan pengisi sebanyak 15 gram, 30 gram dan 45 gram abu arang tongkol jagung, DGEBA 100 ml, MPDA 50 ml. Metode pengujian tegangan tembus berdasarkan standar IEC 1109 dan metode pengukuran hidrofobisitas berdasarkan IEC 62073 yakni metode sudut kontak. Nilai Tegangan tembus tertinggi  pada sampel SI00 (tanpa filler) kondisi kering bersih yakni sebesar 74,64 kV dan tegangan tembus terendah pada sampel SI45 kondisi kering bersih sebesar 17,81 kV. Penambahan jumlah sampel bahan pengisi hanya memperburuk tegangan tembus isolator. Sampel SI00, SI15, SI30, dan SI45 bersifat hidrofilik atau menyerap air. Penambahan bahan pengisi pada resin epoksi juga semakin membuat permukaan isolator menyerap air. Pada sampel dengan bahan pengisi 45 gram abu tongkol jagung sudah mengalami breakdown pada tegangan 17,81 kV sehingga tidak dilanjutkan untuk kondisi pengujian yang lain.This study aims to measure the breakdown stress and hydrophobic properties of epoxy resin insulators with and without corncob charcoal ash as filler. Addition of filler as much as 15 grams, 30 grams and 45 grams of corncob charcoal ash, 100 ml DGEBA, 50 ml MPDA. The breakdown voltage testing method is based on IEC 1109 standard and the hydrophobicity measurement method according to IEC 62073 is the contact angle method. The highest value of the breakdown voltage in the SI00 sample (without filler) is in the clean dry condition of 74.64 kV and the lowest in the SI45 sample in the clean dry condition is 17.81 kV. Increasing the sample size of the filler only exacerbates the breakdown voltage of the insulator. Samples SI00, SI15, SI30, and SI45 are hydrophilic or absorb air. The addition of fillers to the epoxy resin also makes the surface of the insulator absorb air. In the sample with 45 grams of corn cobs ash filler, it has been damaged at a voltage of 17.81 kV so that it cannot be used for other test conditions.

The Polohungo Micro-hydro Power Plant (PLTMH) in Polohungo village, Tolangohula District, Gorontalo Regency has several components, namely intake, headrace, forebay, tailrace, penstock, turbines, mechanical equipment systems, mechanical transmission systems, and generators. The increase of demand for electrical power and the limited capacity of the generator was causing suboptimal plant operation. This study aims to evaluate the performance of the 40 kW PLTMH against the electrical load in Polohungo Village, Gorontalo Regency. The evaluation stage began with the calculation of the technical parameter data of the equipment, which was then compared with parameters obtained from measurement. The evaluation results show that the overall condition of the main components such as generators, turbines, and the generator control system was still working well even though there was no history of maintenance. There was a power difference of 12.212 kW or 55.03% between the real-world generated power and theoretically calculated power based on turbine design water flow. Therefore, PLTMH Polohungo was not operating optimally when handling small-scale power loads, where the amount of power generated by theoretical calculations is greater than the amount of power generated when the generator is operating with a water flow rate of 0.02865 m3/second.

The failure of transformer insulation often occurs due to various kinds of things, one of which is failure in the oil isolation caused by the condition of oil that has been dirty or has been contaminated with other particles in the transformer. Phenol is a chemical that can purify or cleanse particles or impurities that are in used transformer oil, so that it can increase the breakdown stress on used insulation oil. Phenol contains acid which can attract particles and impurities in the transformer oil which results in a decrease in the breakdown strength of the insulating oil. The results of testing of used isolation oil by adding phenol as much as 10, 15 and 20 ml showed an increase in the value of breakdown voltage with a distance of 2.5 mm ball inlet electrode. Translucent stresses that meet the SPLN standard 49-1: 1982, that is ≥ 30 kV at intervals of 2.5 mm were obtained by adding 20 ml of phenol to the volume of used 400 ml transformer oil

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