removing water optimal performance long run expensive repairs optimal temperature perform efficiently carefully dried efficient methods latest methods rrr electricals potentially fail costly repairs corrode leading short circuits environmental factors reduced efficiency electrical distribution key components critical process transformer drying time moisture oil reduces oil resulting oils integrity oils ability transformer moisture transformer oil operational lifespan transformer oil dehydration increased transformer lifespan transformers internal parts heat dissipation efficiency transformer replacements saving vacuum system moisture dehydration important moisture mineral oil acts insulating oil inside oils insulating properties insulation preventing overheating longer period reducing cooling properties benefits particulate matter ensuring steps vacuum dehydration