Evaluasi Resistansi Grounding pada Gardu Distribusi Daerah Kerja PT. PLN (Persero) ULP Medan Kota

Abstract

The grounding system is a conductor connection system that connects the system, equipment bodies and installations to the earth/ground so as to protect humans from electric shock, and protect installation components from abnormal voltage/current hazards. Based on PUIL 2011 and IEEE Std 80-2000, standardization for grounding resistance values of ≤5 Ω. The research method is qualitative, namely a grounding data collection technique, and direct measurement of grounding resistance values at 20 ULP Medan Kota distribution substations, namely Transformer grounding, Lightning Arrester (LA) grounding, and Low Voltage Switchboard grounding (PHB-TR). The type of electrode rod used in the measurement is the rod electrode planted perpendicular to the ground with 1 electrode rod or 2 electrode rods (parallel), made of dyed copper, and the diameter of the rod electrode is 5⁄8 inch = 0.015875 meter. The grounding resistance value that exceeds the 5 Ω criterion is caused by several factors, namely soil resistivity, the size of the grounding electrode installed, the number/configuration of the electrodes, and the depth of the electrode rod embedding. From the results of observations, measurements and calculations, PT. PLN (Persero) ULP Medan Kota is operational because the grounding conditions at the distribution substation are quite good at 3.9324 Ω for swamp land and 4.5717  for field soil and the grounding resistance value meets PUIL 2011 and IEEE Std 80-2000.