In October 1998, El Paso Electric Company's Power Generation Facility in El Paso Texas was honored with the prestigious RBM Excellence Award.* The annual RBM (Reliability Based Maintenance) Award is presented to the plant or company that utilizes a world class Predictive Maintenance (PdM) program, exhibiting outstanding performance in such categories as work processes, people skills, and implementation and integration of multiple technologies. A significant factor contributing to EPEC's RBM success is its onsite oil analysis program. A good oil analysis program catches faults before they progress to a stage detectable by even the best vibration analyst. The value of effective oil analysis has repeatedly proven itself at EPEC through impressive savings and significant cost avoidance. This article examines the evolution of EPEC's oil analysis program and the role it played in helping them to achieve RBM excellence.
Historical Background. El Paso Electric Company has been providing electric power to communities in the Southwest since 1901. With more than 281,000 customers in West Texas and Southern New Mexico, EPEC also sells electricity to wholesale customers in New Mexico, California, and contractually to the Commission Federal de Electricidad de Mexico, the national electric utility of Mexico.
In the early 1990's, with the threat of government deregulation of the utility industry becoming a reality, power generation management at EPEC realized that to remain competitive and to better serve customers, they would have to look at ways to improve equipment reliability in their power plants. With an average equipment age of over 30 years, EPEC's maintenance team needed to develop programs to evaluate and monitor the condition of the equipment and take the necessary action to insure system-wide reliability.
In 1995 Power Generation Management at EPEC took an interest in predictive maintenance technology for the first time. Although the initial startup cost of $30,000 went to purchase software, vibration analyzers, an oil analyzer, and motor current testing equipment, the initial program consisted of only two employees who focused mainly on creation of databases and development of vibration routes. Oil samples were only taken on an "as needed" basis. The success of this initial program (mostly due to the vibration analysis) prompted EPEC management to recognize the first legitimate PdM department in 1996, and two employees and a supervisor were added. In 1997, the PdM staff grew to five when oil analysis and thermography were fully integrated into the program. 1998 saw the addition of an additional employee and the integration of ultrasonic analysis to the PdM arsenal.
Oil Analysis at EPEC. From its birth in 1995, the oil analysis program at El Paso Electric progressed through a steady evolution. In the beginning, oil samples were collected as needed from only a few pieces of equipment. In other words analysts only took oil samples when a machine exhibited some sign of a problem. Continuity was also a problem since maintenance personnel were periodically rotated out of the oil program. Then, significant savings directly resulting from the oil program provided the catalyst for upper management to take the oil analysis program more seriously. At this point, employees were permanently assigned to the oil program and sample points were added to EPEC's existing vibration database. Sample points were assigned for each production critical machine and for bulk oil storage. In the first year the program documented 92 oil contamination cases, which were compiled in a database where a cost analysis was performed.
Today at EPEC, oil is sampled from 393 oil sampling points on 121 different machines located in three separate plants. The majority of tests are performed on a monthly basis using a CSI Model 5100 Oil Analyzer and 100X microscope for routine screening and condition monitoring. Work is verified from time to time using the lube supplier and an independent test lab. The same person who takes the samples also runs the tests. All of the test results are automatically entered in the MasterTrend database, along with the usual vibration, motor current, alignment, and balancing data. All personnel in the maintenance and operations departments have access to the database. Any samples that fail are re-tested and a report with recommendation for the problem correction is sent to the maintenance supervisor, maintenance engineers, and planners.
In 1997 as part of the program, the maintenance team looked at the cleanliness levels on the large reservoirs (turbines/generators and bulk oil storage tanks) to see how the oil compared to targets using ISO standard 4406. It was discovered that the existing oil was nowhere near the desired cleanliness levels of ISO 14/12 for 5-15 micron levels. The team also looked at the filtration system and found that it was not adequate to meet current fluid cleanliness requirements. EPEC decided to upgrade the filtration systems from nominal cartridge-type to a high efficiency kidney-loop type.
In an effort to ensure adequate cleanliness, oil samples were sent to the oil supplier for extensive testing. Unfortunately, the oil failed many of the tests. Two units were running with oil very near its condemnation limit level. There were no records to indicate how long the oil had been operating in this condition. The best option was to go with an onsite reclamation and refortification offered by the lubrication supplier. Blend studies were performed to determine what it would take to bring oil back to target requirements. The blend studies suggested 30% new oil blend with the used oil to restore acceptable additive levels. Test results after oil reclamation indicated that the oil was now suitable for continued use with a guarantee from the vendor.
One of the most important parts of getting the program started was training in basic lubrication and contamination control. Through EPEC's training program, employees were taught that not all oils and greases are the same and do not always mix well. They also gained a good understanding of what size particles in the lubricant can cause damage. Training also addressed issues such as contaminated transfer containers and oil handling practices.
Another area targeted for improvement was lubrication management. Several lubrication manufacturers were invited to bid for EPEC's lubrication contract. Lubrication quality, vendor support, and price were among the more important selection criteria. After selection of a vendor, EPEC proceeded with a lubrication survey of all EPEC plants. The following actions were taken as a result of this survey:
The value of EPEC's oil analysis program becomes evident through a careful analysis of the numbers. In 1996, after the oil analysis program was implemented, the savings based on vibration analysis went down while the oil program saw a cost avoidance of $375,000. Again in 1997, as the oil program matured, the vibration savings went down as it became balanced against the $900,000 cost avoidance of the oil program. These figures provide compelling evidence of how valuable a modern oil analysis program can be and how oil condition is closely related to other condition monitoring technologies.
The Bottom Line
El Paso Electric Company's PdM program has resulted in a cost avoidance of $8.8 million over a period of three years. The total is broken into the following categories for each year.
1995 Cost Avoidance: $3.1 Million
Vibration Analysis: $2.8 Million
QA/QC and Root Cause: $.3 Million
1996 Cost Avoidance: $2.5 Million
Vibration Analysis: $1.7 Million
Oil Analysis: $375,000
1997 Cost Avoidance: $3.1 Million
Vibration Analysis: $500,000
Oil Analysis: $900,000
QA/QC: $1.1 Million
It is important to note that over the three-year period, the vibration analysis program was not losing its effectiveness, but rather oil analysis provided an early detection of problems that would have later led to vibration faults. No single program can continue to deliver additional savings year after year that equals the impact of the first year or two. It requires the addition of new capabilities, in this case oil analysis, to further the performance gains. It is equally important to maintain the established condition monitoring programs to avoid a return to the pre-program maintenance cost levels. Continuity of effort and program growth to the point of optimization (profit maximization) are key to success.
Conclusions. The oil analysis program has been a successful and integral part of EPEC's PdM/RBM program. Since inception three years ago, the integrated condition monitoring program has delivered a documented $8.8 million in cost avoidance. Because maintenance cost avoidance has no associated cost of goods sold, these dollars go straight to the bottom line profitability of the company. Reduced Equivalent Forced Outage Rate (EFOR), increased Equivalent Availability Factor (EAF) and improved safety record provide further evidence of the program's success. EPEC has additionally seen improved labor utilization and decreased production insurance premiums as a result of improved equipment reliability. These clear indications of success at EPEC provide compelling evidence that a well conceived reliability management program that utilizes a multiple technology approach increases bottom-line and top-line performance, and that oil analysis is a key player in achieving that success.
*Sponsored by CSI