Pengaruh bentonit parit melingkar terhadap nilai resistans pentanahan satu batang pentanah

STEPHANUS, Harnoko, Ir. T. Haryono, MSc

2003 | Tesis | S2 Teknik Elektro

Resistans pentanahan dengan menggunakan batang pentanah tergantung pada jenis, keadaan tanah, ukuran dan cara pengaturan elektrode pentanah. Pentanahan dengan menggunakan batang pentanah pada teknis pelaksanaannya lebih praktis daripada menggunakan elektrode pelat atau elektrode pita. Nilai resistans pentanahan tersebut harus sekecil-kecilnya. Nilai resistans pentanahan dapat diperkecil, antara lain dengan memparalel batang pentanah atau dengan perlakuan terhadap tanah (soil treatment). Bentonit (Al2O3.4SiO2.H2O) dapat digunakan untuk memperrendah nilai resistans pentanahan karena bersifat menyerap air. Bentonit mengandung air (H2O) sehingga dapat mempertahankan kelembaban tanah. Dalam penelitian ini digunakan elektrode pentanah berbentuk batang silinder pejal dengan panjang 1,0 meter dan diameter 12,7 mm. Batang pentanah ditanam dalam tanah dengan pangkal batang berada di permukaan tanah, pada satu jenis tanah. Pengukuran nilai resistans pentanahan dilakukan tanpa bentonit dan dengan diberi bentonit parit melingkar. Hasil penelitian menunujukkan bahwa nilai resistans pentanahan satu batang pentanah tanpa bentonit adalah 164 ohm. Nilai resistans pentanahan dengan bentonit parit melingkar adalah 124 ohm sampai 31 ohm. Penurunan nilai resistans pentanahan berada antara 24 % sampai 81 %. Hasil ini sesuai dengan IEEE Standard 141–1993, yaitu nilai penurunan antara 15 % sampai 90 % bila diberi bahan kimia (chemical treatment). Hasil lain adalah semakin dalam parit bentonit, semakin rend ah nilai resistans pentanahan 1 batang pentanah. Semakin lebar parit bentonit, semakin rendah nilai resistans pentanahan 1 batang pentanah.

Grounding resistance of a ground rod depends on the type of soil condition, dimension and arrangement method of the ground rod. The ground rod is more practice than ground plate or ground strip. The value of grounding resistance must be as small as possible. It is difficult to reach the value of the grounding resistance that full- fills the standard. There are some ways or methods to make a grounding resistance value being small, such as making parallel ground rod or applying soil treatment. Bentonite (Al2O3.4SiO2.H2O) can be applied to lowering grounding resistance value, because it has a capability to absorb the water. Bentonite contains the water element (H2O) so that it is capable to maintain the ground humidity. The ground rods used to in this experiment are cylinder rods with the length of 1 meter and the diameter of 12.7 milimeters. The rod is breed into earth. One end of the rod is on the ground surface. The grounding resistance value of the rod without bentonite is compared with the grounding resistance value of the rod with circle trench bentonite. The depth and diameter of circle trench bentonite are varied. The experiment results show that the grounding resistance value of one ground rod without bentonite is 164 ohms. The grounding resistance value of one ground rod with the circle trench bentonite is 124 ohms untill 31 ohms. The decrement of the value of the grounding resistance with bentonite is between 24 % to 81 %. This results agree with the IEEE Standard 141-1993. This standard state that the decrement of the grounding resistance of the one rod with chemical treatment are 15 % untill 90 %. The grounding resistance value of one ground rod without bentonite is higher than that of with bentonite. The value of circle trench width of bentonite is higher, the grounding resistance value is lower. The value of circle trench depth of bentonite is higher, the grounding resistance value is lower.

Kata Kunci : Listrik,Bentonit Parit Melingkar,Resistans Pentanahan