Assessing the impact of three-phase rewinding of a failed single-phase motor on efficiency improvement and energy saving

Induction motors, particularly single-phase induction motors (SPIMs), represent the major consumption of power in the household sector. SPIMs that fail during their life cycle represent the best opportunity to improve their efficiency by replacing or repairing them. Although replacing faulty motors with new and efficient ones results in significant energy savings, this replacement is uneconomical due to its high initial costs. Additionally, this option requires extensive energy and materials to manufacture, resulting in a considerable environmental impact. This article aims to introduce a three-phase rewinding of a failed SPIM using a rewinding algorithm that significantly improves the machine's efficiency and performance in an economically viable way. The 0.75 HP single-phase capacitor-start induction motor has been rewound to convert it into a three-phase motor with the required 110 V line voltage and 50 Hz frequency. The economic analysis implies that the rewound machine's life-cycle cost is 6% and 18% lower than the purchased SPIM IE1 and existing SPIM by below efficiency class respectively. The rewound motor achieves a payback period of 1-1.6 years for different motor loading levels, based on the world average electricity price, indicating an economically viable solution.