Evolving CP System Management: Creation of an Automated Screening Framework for RMU Analysis

Abstract This study presents a framework for establishing the upper and lower DC current thresholds for rectifiers by leveraging Remote Monitoring Unit (RMU) data to enhance system-wide monitoring and identify abnormal operational behavior. Historical RMU amperage data was consolidated, cleansed and a 30-point moving average methodology was applied to smooth the data. Statistical truncation removed fringe values at the lower bounds of the refined dataset to improve clarity and increase accuracy of the calculated DC current limits. Rectifiers across the entire asset management portfolio were then catalogued and DC current range was graphically represented on a histogram to perform system-wide screening and identification of outlier extremes. Program subject matter experts (SMEs) were provided with priority sites for review to determine if intervention or manually revised DC current limits were required. The finalized thresholds were integrated into the corrosion prevention database and programmed into the physical RMUs enabling field technicians to assess cathodic protection (CP) system performance in real time. Additionally, a visualization tool was developed to facilitate efficient review of the established limits alongside historical current readings and relevant metadata for each RMU. With implementation of automation, rectifiers exhibiting normal operational behavior will no longer require annual adequacy analysis, while rectifiers showcasing concerning DC current trends will be flagged for SME assessment. This framework enables predictive integrity management, fosters intelligent investment decision-making and streamlines monotonous manual site-by-site analysis traditionally performed by program SMEs.