Three-phase induction motors are one of the most widely used electrical machines in industry due to their simple construction, low maintenance costs, and high performance. However, motor efficiency is significantly affected by various power losses, such as copper losses, iron core losses, mechanical losses, and stray losses. This study aims to analyze the efficiency of a three-phase induction motor with a nominal power of 55 kW, a voltage of 380 V, and a current of 105 A using the loss segregation method,
which separates the power loss components based on test results. The analysis results show that the smallest losses are in the stator and rotor copper losses, while iron core
losses and mechanical losses are relatively larger. Calculations show that the motor efficiency at full load ranges from 92.28% to 93.21%, which still meets the IEC standard for motor efficiency with standard class (IE1). Thus, the loss segregation method has proven effective for the performance of three-phase induction motors and can be used as a reference for improving and increasing the operational efficiency of electric motors in industry.