Load imbalance in a three-phase four-wire system can increase neutral current, conductor heating, and reduce utilization of distribution equipment. This study aims to: (1) determine the level of current imbalance and compare measured neutral current with the theoretical resultant; (2) calculate the apparent power associated with neutral current and its percentage relative to transformer capacity; and (3) determine load-balancing priorities based on electrical indicators. A quantitative descriptive case-study approach was applied using secondary data from the PI0483 Distribution Substation on the Merapi Feeder in Indralaya. The 100 kVA transformer supplies two circuits, with R-S-T phase currents of 26-15-16 A for Circuit I and 71-85-38 A for Circuit II. The results show imbalance levels of 24.56% and 27.49%, respectively. Measured neutral currents were 13 A and 47 A, while theoretical values were 10.54 A and 41.80 A. At an average phase-to-neutral voltage of 234 V, the apparent power associated with neutral current was 12.25 kVA based on calculated currents and 14.04 kVA based on measured currents, equivalent to 12.25%-14.04% of transformer capacity. Circuit II is prioritized for load balancing because of its higher imbalance, neutral current, phase-current range, and neutral-current apparent power. These findings highlight the importance of load redistribution and monitoring.
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