Up Time Magazine- June/July 2008

precision maintenance upload Smart Maintenance Promoting Predictive Maintenance for Equipment Reliability by Brian Thorp Y our predictive maintenance program is up and running. You have had some good finds and saves, but are you putting all of the information you collect to use? There is a lot more useful information in that data than just lubricant quality, trends, and failing components. Aside from the reliability aspect that predictive maintenance can provide, there are significant cost savings potentials available though effective “smart” maintenance – Doing the right thing, at the right time, and for the right reason. motors was substantial as well. There is approximately 550 gallons of oil for all of our oiled motors. The actual cost of the oil times 4 (industry average real cost) equals, $15,400 per year. While this may not be that much money per year, when you take into consideration we can run three to five years without changing oil, you are now looking at $46,200 to $77,000 total savings over this time period. The bottom line is: Smart maintenance, less human intervention, cleaner running motors, less chances for oops and ingression of debris = cost savings. There are many other pieces of equipment that can benefit from CBM for “smart maintenance”. We have three Cooper-Joy, three stage centrifugal compressors (Figure 2) which ran for five years (40,000 hours) without an oil change. When this equipment was being installed the O.E.M. recommended a 5,000 hour oil change frequency. After contacting the manufacturer and qualifying our oil analysis program the 5,000 oil change was waived based on oil analysis for CBM. These three compressors now have the oil changed during the five year rebuild. This is a savings of over $110,000 (4 X’s cost, industry average real cost) for the five year period. Another piece of large reservoir equipment, our 25,000 CFM blowers (Figure 3) provide air to convert our scrubber slurry to synthetic gypsum. These had O.E.M. guidelines of 5,000 oil changes that were waived based on oil analysis for CBM. The oil was changed at the 40,000 hour interval based on a RVPOT which indicated the oil was at 25% of its original value. With three of these blowers, this is a cost savings of over $184,000 for the five year period (4 X’s cost, industry average real cost). Our twelve coal ball mill gear reducers are the last equipment to be referenced for CBM oil changes. Originally set up for six month oil changes on a PM, these accounted for almost 750 gallons of oil per year. We now average 2.5 to 3 years before an oil change is needed based on oil analysis. These gear reducers are june/july 2008 So what is effective or smart maintenance? Of course, you would consider CMMS, preventive maintenance, planning/scheduling, and maintenance procedures to name a few. Webster’s collegiate dictionary describes it as: Effective: producing a decided, decisive, or desired effect, and Maintenance: the act of maintaining, the upkeep of property or equipment. This article will primarily focus on the additional information that predictive maintenance can provide to help you work towards achieving effective “smart” maintenance. Oil Analysis and Condition Based Maintenance (CBM) Most electric motors have small volume lubricant reservoirs and thus, oil analysis is generally done for equipment condition rather than lubricant quality. Why not use it for both? Our oiled motors where originally set up with a one year frequency PM for oil changes. Even with good lubricant handling practices there were still significant swings in the ISO code cleanliness. The high spike was generally right after an oil change with the cleanest being right before an oil change. We have all heard about the dirt in circulation of a hydraulic system and the damage it causes. A motor may not have the same flow as a hydraulic system, but the slinger rings do a great job of circulating wear debris within the bearing reservoir. Of course, this causes wear to the shaft journal and the slinger ring showing up as iron, chromium or brass in the oil analysis. Unfortunately, most motors do not have circulation systems or filtration to remove wear debris. Once they are there, they must slowly settle out to be stirred up again during an oil change. Figure 1 graphs show the particle counts on oiled motors before and after of CBM. As can be seen by these graphs, once CBM was established for the oiled motors, the particle counts dropped noticeably and has remained low. The cost savings associated with the CBM for the oiled 46

Table of Contents Feed for the Digital Edition of Up Time Magazine- June/July 2008

Up Time Magazine- June/July 2008 Contents Upfront Upclose: The True Cause of Most Machine Failures Information Technology: Finding Future Perfect Lubrication: Building an Oil Analysis Winner Maintenance Management: Hidden Ways to Increase Safety Infrared: Air Barriers Lower Energy Costs, Increase Profits Motor Testing: Efficient Motor Repair, Part Deux Precision Maintenance: Good Maintenance, Smart Maintenance Reliability: Common Errors in Root Cause Analysis Ultrasound: Avoid the Baghouse Blues Vibration: Don't Let Your Sensors Get Eaten Alive Upgrade: Lining It All Up

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