Efficiency value is a measure that can inform us that a machine that operates can be said to be efficient or not. This study aims to find the efficiency value of the electric generator on the fishing vessel KM. Maradona. In addition, this study also aims to find the average percentage value of electric current on each phase of the generator and also to find the average value of the percentage imbalance of load sharing in three-phase electrical installations in KM. Maradona. From the calculation, it is found that the percentage of imbalance of three-phase electrical installations KM. Maradona when the generator operates can reach 31.11%. From the calculation, it is also found that the average percentage load on the electric generator of KM. Maradona maximum value is 22.35% with an average current value of 25.50 Ampere. Directly proportional to the maximum average current value, the maximum electrical power value of KM. Maradona is only at 16.80 kVA with an efficiency value of 22.40%.