Dynamic Positioning is a control system that can maintain ship position to the object on the horizontal axis. With the degree of freedom of the ship, the Dynamic Positioning system maintains the position of the ship from sway and surge movements. With the degree of freedom of the ship, this system maintains the position from sway and surge movements. On its operation, there is closed bus and open bus where the open bus has advantages of reliability and closed bus have better fuel efficiency. The term short circuit fault is used to explain that the conductor is briefly connected. There are two values of short circuit current failure that must be evaluated. The maximum value of the short circuit current will be related to the short circuit current in the terminal around the protection device. The minimum value of this current is important to use when selecting the current-time curve for circuit breakers and fuses. On this paper, the author use impedance method that's based on the IEC 60909 standard. Based on an experiment that held in laboratories, each load variation and scenario have their own trend value. The highest initial symmetrical short circuit current that obtains both on impedance method and conventional method were found at 2nd scenario and 60%-60% load variation, the value that obtains in impedance method is 2.5158 ampere and the value that obtain on with conventional method is 3.91 ampere.