Luminant is the largest power producer in Texas and the company’s mining division is the state’s leading producer of lignite coal, producing roughly 33 million tons per year to meet the fuel needs of our lignite plants. Mine Maintenance Support Services (MMS) is responsible for providing support for 15 draglines, 10 loading stations, 45 conveyors, Luminant’s railroads and 500 pieces of mining rolling stock spread across eight separate mines in Texas. The area encompassing the mines stretches nearly 325 miles from northeast to central Texas.

Luminant’s MMS group is the driving force behind implementing, maintaining and auditing its condition monitoring program and, over the past few decades, the MMS team has helped develop it into a world-class program. We like to consider the MMS group as many faces, but one name.

Our goal is asset preservation. We do this by identifying changes in the condition that indicates a potential failure (P-F curve). Each of these characteristics is measured, analyzed and recorded to help our team recognize trends and take appropriate actions before they become an issue.

Our corporate maintenance standardization initiative, Conduct of Maintenance (COM), allows us to allocate funding, using reliability centered maintenance (RCM) analysis, to do the right tasks at the right time in an efficient, cost-effective and safe manner. Over the past four years, we have seen an eight percent improvement in asset availability and an 18 percent reduction in maintenance spend.

The COM was also developed to help standardize fleet-wide procedures with a repeatable and measurable workflow process that would improve reliability and availability. The new program also uses metrics to track progress and set goals. Maintenance superintendents, supervisors and technicians are given goals based on factors they can control, instead of factors they cannot, such as reducing maintenance costs.

Employees of each MMS department have different levels of expertise, which combined provide quality electrical engineering support; mechanical engineering support; technical support; maintenance control that maintains the mining computerized maintenance management system (CMMS); and RCM and predictive maintenance (PdM) reliability support, planning and performance, training, supplier quality and project management support.

MMS unifies the functional departments of each site with the support organizations to maintain mining assets and improve asset health and reliability. The MMS toolbox consists of many activities to prolong and maintain the life of our assets, including:

• Condition-based maintenance (CBM);
• PdM and non-destructive testing (NDT);
• RCM

Figure 1: Site equipment and reporting grade

Figure 2: Heavy equipment dragline grade

Luminant’s condition monitoring program is broken down into several departments, equipment, components and systems, including:

MAINTENANCE CONTROL

• Monitors and maintains all data coming and going from our CMMS.
• Mining CMMS (MAC/MAXIMO)
• COM – Work management guidelines and rules to live by
• Maintenance-Compliance Assisted Visit (M-CAV)
  • Yearly site assessments;
  • Review scoring, planning, scheduling and Preventive Maintenance (PM) optimization (RCM courtesy);
  • CAV measurements;
  • Corrective Action Process;
  • Corrective Action Program (CAP) overview – Closeouts identify Corrective Actions (CAs) and owners and are then posted on Safety Tracking Program (STP) site for weekly review with a status of M-CAV;
  • Year-end updates – For each section review, bring Systems Maintenance Engineer (SME) all questions for scoring, validity and improvements; communicate changes to sites;
  • RCM – Data.
• Standardization Information Sharing – Training new employees and working with training group.
• Information Sharing – Manager, superintendent, planner, first line and tech meetings.
• Planning Strategy – Absorb scheduling role, share day-to-day activities, training, office locations, review with managers, superintendents and supervisors.
• Metrics.

MOBILE EQUIPMENT MONITORING

• Mining Power Optimization Center (POC) provides us the capability to run numerous reports for specific evaluation including, idle time, location, haul cycle time, equipment operating parameters and fuel burn for engine performance monitoring. Mining POC tracks and manages all equipment alerts and warnings, which are sent by email and text to designated mine personnel. Software report samples are shown in Figures 3 and 4.
• Total Tire Care (TTC) – Track and evaluate large mining tire performance. Manage the inventory, performance and forecast usage of all equipment tires, from forklift size all the way up to our largest earthmover tires, critical to maintaining equipment operation. Key indicators are tracked for each individual tire, including pressure, tread depth, position on the equipment, remaining life and value remaining.

Figure 3: Equipment health report

Figure 4: Site health report

OIL ANALYSIS TRACKING AND REPORTING

• Contamination Control, Bulk Tank and Point of Use (POU) – The single greatest opportunity for increasing component life and lowering operating costs is to effectively manage fluid cleanliness. Several key initiatives are in progress at Luminant to improve our fluid cleanliness, including specialized software for oil analysis tracking and reporting.
• The ISO cleanliness standard has improved from an average of 21/19 to an average of 18/16, which is a 700 percent improvement.
• The use of all oils and lubricants, as compared to August 2011, has decreased by 65,000 gallons and resulted in $520,000 in cost avoidance.

Figure 5: Assembly Line Preventive Maintenance (ALPM) oil sample station

Figure 6: Bulk oil filtering system

HEAVY EQUIPMENT MONITORING

• Dragline Booms (I-beam and pressurized pipe) are monitored by taking data from the motors. It is also looking at strain gage data from intermediate suspension lines and other data sources to evaluate damage created in the boom due to loading of the boom – both static and dynamic loading. This system takes into account any shocks or other dynamic phenomenon that occurs as the machine is in operation and in near real time. Through the use of a boom model, the interface indicates areas where damage is occurring and alerts the user to areas of potential risk due to aggregated damage. This data can be used, along with our camera footage that watches work going on around the machine, traffic, or personnel on the ground while the machine is digging and viewing the machine house while running. It has been utilized by the mine sites as part of a root cause analysis (RCA) event or to help correct errors. Wireless, online air pressure boom monitoring is used to help locate leaks from cracks in the main boom and mast cords. We use the data to help determine the urgency for scheduling an inspection and repair.
• Dragline and conveyor motors are monitored for real time temperature, vibration, voltage, current and other process values. Motor components are also audited internally twice a year for on-site repairs or for outage replacement.

PDM/NDT TECHNOLOGIES

From ultrasonic, ultrasound, infrared (IR), vibration, magnetic particle, liquid penetrant, weld inspection and electrical motor analysis are used to monitor and evaluate components. Currently, 100,000 points are inspected and monitored yearly across the eight mining sites.

Figure 7: Infrared leaking insulator

Figure 8: Ultrasound inspections on bearings

Note: Ultrasound is used with Luminant’s IR program to help find early stage corona and tracking during days or nights.

Through successes and challenges, we have obtained a significant amount of data, which has helped build and modify procedures and processes in condition monitoring. Sharing our results with original equipment manufacturers (OEMs) of heavy and mobile equipment has led to new and better designs in some components, which has helped the industry as a whole. One premature failure is one failure too many in our industry, but continuing to deploy sustainable technologies and measuring our results will guide us to the next level in condition monitoring.

We believe that where you have started is just as important as where you are now. As far as the future, we believe the best is yet to come.

Past, Present and Future....