การลดความสูญเสียในการบำรุงรักษาเชิงป้องกันมอเตอร์ กรณีศึกษาโรงงานแยกก๊าชธรรมชาติ

Abstract

This research aimed to reduce loss of preventive maintenance for 239 important motors from totally 350 motors in a gas separation plant. This activity was performed according to Total Productive Maintenance (TPM) project in this plant. The research methodology followed the step of QC Story. Failure Mode and Effect Analysis (FMEA) was also used for analysis of root causes and to propose the improvement methods. The analysis of the reliability of the system by applying reliability engineering was performed. The result from the analysis by FMEA found that bearing part was highest RPN (Risk Priority Number) score. The result from the analysis by reliability engineering showed that the reliability of motors in the redundancy system in a case study plant remained 89% after running the system for period of 5 years (40,000 hrs). Therefore, the guideline of new preventive maintenance method was proposed by extending the interval time to overhaul those critical motors. The condition based maintenance (CBM) method was introduced. The result from FMEA analysis was used to define and improve preventive maintenance actions. The results of this study indicated that the extended interval time of motor overhaul in the study period was effective since there was no breakdown during monitoring period. This could reduce preventive maintenance cost by 73.47% (while target was 40%). Finally, new standard with the extended interval time for overhaul motors in a case study plant was set.