The transmission network in the PT. PLN (Persero) GI Cikupa electric power system has a load far from the generator so that power losses cannot be avoided. However, it is not yet known how big the power losses are, whether they are still within the tolerance limits according to SPLN No. 72 of 1987, power losses are limited to +5%. This thesis research uses quantitative research methods by calculating resistance parameters and modifying the ACSR Zebra and ACSR ORANGE conductor wire types to see the effect of power losses at the Cikupa substation. The effect of the same type of conductor wire with different cross-sectional areas on power losses is that the smaller the resistance of the conductor wire and the larger the cross-sectional area, the smaller the power losses and vice versa. In the ACSR Zebra conductor type with a resistance of 0.3118 Ω and a crosssectional area of 484.5 mm2, the highest power loss was 3.2% on May 20 2024 and the lowest power loss was 1.6% on May 28 2024. Meanwhile, for the ACSR ORANGE 1120 conductor type with a resistance of 0.295 Ω and a cross-sectional area of 506 mm2, the highest power loss was on May 20 2024 at 3.1% and the lowest power loss was on May 28 2024 at 1.6%. Based on research, the power losses of the ACSR Zebra conductor are greater than the ACSR ORANGE 1120 conductor.