ANALISIS TAHANAN ISOLASI PADA ISOLATOR PORSELIN DAN POLIMER TERHADAP POLUTAN GARAM DI GISTET 500 KV ADIPALA CILACAP
Authors: Darmadi Agam Celvano , Kholistianingsih Kholistainingsih , Yulianto Priyono 
Published: July 2023

GISTET 500 kV Adipala is one of the locations that is in the spotlight in the Central Java Transmission
Main Unit (UIT JBT) because of frequent pollutant problems, especially during the dry season. This causes
the surrounding air to have a high salt content and also the flyash from the PLTU. This condition causes
the insulators on the tower and gantry to be exposed to pollutants and can result in flashover and
breakdown. This study discusses the effectiveness of polymer insulators by testing the insulation resistance
of clean porcelain insulators, polluted porcelain, clean polymers, and polluted polymers. To get the
condition of the insulator polluted with salt water, the method of raining on the insulator is carried out.
The result of the clean porcelain test was 2970 GOhm. in the experiment with polluted porcelain insulators,
the following results were obtained: the minimum 50ml experiment measured a resistance value of 2950
GOhm, which was reduced by 1% from the clean one and the maximum 500ml experiment measured the
resistance value to 390,3 GOhm, which was 87% reduced from the clean one. The net polymer insulator test
results are 3222.8 GOhm. In the experiment with polluted polymer insulators, the following results were
obtained: the minimum 50ml experiment measured a resistance value of 2982 GOhm, which was 7% less, the
maximum 500ml experiment was 2382.8 GOhm, 26% less. From the results of these experiments, it can be
seen that in the porcelain insulator experiment with salt water polluted, the insulation resistance value
decreased in each experiment until the maximum experiment was 500ml which obtained a resistance value
of 390.3 GOhm. The results of the clean polymer insulator test were 3222.8 GOhm, while the pollutant polymer
insulator experiment recorded a value that was not significantly decreased with the lowest value in the
500ml experiment of 2382.8 GOhm. When compared with the minimum standard of insulation resistance for
the 500 kV system used by PLN is 500 MOhm. Porcelain insulators that experience continuous exposure to
pollutants have the potential to experience flashover and faster breakdown compared to polymer insulators
when viewed from the trend of decreasing insulating resistance. It can be concluded that polymer insulators
are more effective for use in environments that have a high level of exposure to air pollution such as at
GISTET Adipala.
Keywords: Porcelain Insulator, Polymer Insulator, Pollutant, Flashover, Breakdown

GISTET 500 kV Adipala adalah salah satu lokasi yang menjadi sorotan di Unit Induk Transmisi Jawa
Bagian Tengah (UIT JBT) karena seringnya masalah polutan terutama pada musim kemarau. Hal ini
menyebabkan udara sekitar memiliki kandungan garam yang tinggi dan juga flyash dari PLTU. GISTET
Adipala. Hal ini menyebabkan isolator pada tower dan gantry menjadi terpapar polutan dan dapat
mengakibatkan terjadinya flashover dan breakdown. Oleh karena itu diperlukan analisis efektifitas isolator
polimer dengan cara melakukan pengujian tahanan isolasi terhadap isolator porselin bersih, porselin
berpolutan, polimer bersih, dan polimer berpolutan. Untuk mendapatkan kondisi isolator berpolutan air garam, dilakukan metode penghujanan ke arah isolator. Hasil pengujian porselin bersih tercatat 2970 GOhm.
pada percobaan isolator porselin berpolutan didapat hasil sebagai berikut: percobaan 50ml, terukur nilai
tahanan sebesar 2950 GOhm, yaitu berkurang 1% dan percobaan 500ml terukur nilai tahanan sebesar 390,3
GOhm, yaitu berkurang 87%. Untuk hasil pengujian isolator polimer bersih sebesar 3222,8 GOhm. 50ml terukur
nilai tahanan sebesar 2982 GOhm, yaitu berkurang 7%, 500ml yaitu sebesar 2382,8 GOhm, berkurang 26% dari
yang bersih. Dari hasil percobaan tersebut dapat dilihat pada percobaan isolator porselin berpolutan air
garam adalah nilai tahanan isolasi yang menurun pada tiap percobaan hingga percobaan paling banyak yaitu
500ml yang diperoleh nilai tahanan 390,3 GOhm. Hasil pengujian isolator polimer bersih sebesar 3222,8 GOhm,
sementara percobaan isolator polimer berpolutan tercatat nilai yang tidak begitu turun dengan nilai paling
rendah pada percobaan 500ml sebesar 2382,8 GOhm. Jika dibandingkan dengan Standar minimal tahanan
isolasi untuk sistem 500 kV yang digunakan PLN adalah 500 MOhm. Isolator porselin yang mengalami
paparan polutan secara terus menerus berpotensi mengalami flashover dan breakdown lebih cepat
dibandingkan dengan isolator polimer jika dilihat dari trend penurunan tahanan isolasinya. Dapat
disimpulkan bahwa Isolator polimer lebih efektif untuk digunakan pada lingkungan yang memiliki tingkat
paparan polusi udara yang tinggi seperti di GISTET Adipala.
Kata Kunci: Isolator porselin, Isolator Polimer, Polutan, Flashover, Breakdown