The system operating at PLTD Tanjung Belit is an isolated system system using diesel engines to meet the availability of electricity in the upstream Rokan area. However, along with the use of fossil fuels, PLTD needs to be dedieselized to meet the availability of electricity in the sand area. In an effort to dedielize PLTD and switch the load to a 20 kV system, the sand of the sand makes the system undergo a change in the existing conditions that cause the Voltage Drop in the striated feeder with values that exceed the Fall Voltage tolerance limit as in the bus voltage ranging from 17.85 kV to 17.90 kV. The condition (State) of the bus is in the range of 89.24% to 89.45%. After scenario 1 is applied, namely Tap Changer, the bus voltage ranges from 18.01 kV to 18.05 kV. The condition (State) of the bus is in the range of 90.03% to 90.26%. The bus with the highest voltage (18.05 kV) is DD. 09 and SMPG, which also had the best condition (90.26%). In the application of scenario 2, namely the reconfiguration of the network the voltage falls ranges from 17.89 kV to 17.99 kV. The condition (State) of the bus ranges from 89.43% to 89.94%. Once applied, the bus voltage varies from 18.04 kV to 18.14 kV. The condition (State) of the bus ranges from 90.21% to 90.72%. The bus with the highest voltage (18.14 kV) is DD. 15, which also had the best conditions (90.72%). Changes in the voltage profile are caused by several factors such as lack of generating power, conductor length, and also the type of conductor used, not only that, this condition causes power losses in the conductor but the value is still relatively stable with a value of 0.2% so it does not have much effect on electrical conditions.