Electrochemical power converters (rectifiers) are robust, reliable dc power supplies when first installed. They produce tens of megawatts of power 24/7 and have a typical design life of more than 20 years. Because industrial managers have become accustomed to this reliability, they often allow demands in other parts of a plant to divert maintenance resources from these machines that are so vital to production. Rectifiers are custom made, and a lack of maintenance often results in extensive downtime and costly repairs. This article provides a review of maintenance procedures and industry best practices, based on manufacturers&#x02019; recommendations, 25 years of rectifier industry experience, and lessons learned within a wide variety of operating electrochemical plants.