Electrical Troubleshooting Quiz — May 18, 2021
A production line of moderately high importance (number 8 among 22 lines for revenue) has been modified numerous times over the years. Many of the mechanical parts, such as arbors, brackets, and travel rails, have been made in the machine shop.
Controls also have been fabricated and retrofitted to this line, including proximity switch-actuated doors and dampers, temperature-controlled fans, and line speed controls that interact with VFD-controlled motors. The line has undergone several PLC upgrades.
There were good reasons for all these modifications, but they are poorly documented. Some are documented with only hand sketches and notes on paper. Others have some rudimentary CAD drawings available. The preventive and predictive maintenance procedures are similarly sketchy.
Over the past few months, this line has had an excessive number of unscheduled shutdowns due to the failure of some component or subsystem. How can you get downtime back under control?
You need to conduct a Pareto Analysis on the downtime failures. Put them on a set of spreadsheets that you can sort by frequency, subsystem, failure cause, PM tech, and repair tech.
Now you can analyze and characterize the failures. You will probably find one cause that stands out across all subsystems; perhaps, by frequency, it accounts for 80% of all failures.
Or perhaps one subsystem stands out as the primary point of failure. If you impose one analysis on top of another (perhaps using a line display versus a bar display), you may find a correlation between one type of repair and two repair techs versus that repair and all the other repair techs.
Focus on the problems that stand out. Solve for cause and correct deficiencies in the documentation related to the problem.
About the Author
Mark Lamendola
Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.
Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.
Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.