October 20, 2005
The Best Offense Is A Good Defense
We offer the contamination control solution that helps you optimize your fluid power, cut back on your maintenance costs & meet your most vigorous production demands. The Des-Case breathers simply replace your standard filler/breather caps to defend your systems against opposing contaminants.
Des-Case offers a full line of disposable, steel, & specialty breathers to meet the needs of any industrial application.”
Please call Des-Case at 615.672.8800 or…
October 20, 2005
Maintenance Tip: Mounting Resonance
A sensor’s high frequency usable limit is a function of the resonance of the accelerometer. Sensors with a higher resonance will generally be small, light weight, and specially designed. These transducers will then be usable to read high frequency vibration signals.
However, the mounting method of the sensor will have a significant impact on its “as installed” resonance and high frequency limit. Each mounting method has an associated resonance. If the mounting resonance is less than the sensor resonance, the high frequency limit of the sensor will be compromised.
In general, the more intimate contact between the sensor and machine surface, the better chance the “as installed” resonance and high end response will be in line with the sensor specifications.
For more information on vibration sensor mounting, including the specific capabilities of 6 different mounting methods, read Wilcoxon’s Technical Note 21: “Mounting Considerations,” in Wilcoxon’s extensive online Knowledge Desk.
October 20, 2005
Family Analysis Alarming Methodology White Paper
Insight Services has developed a white paper on their family analysis alarming methodology that they are offering free of charge for Reliabilityweb.com visitors.
Insight Services’ white paper on their family analysis alarming technology in oil analysis explains how they are uncovering machine problems sooner. This method has been in proven use for over a year and a half and customers are really starting to understand the importance of dynamic alarm levels.
October 20, 2005
Reliability Centered Maintenance (RCM) Tip
How to Select RCM Facilitators
One of the most important phases in starting a successful RCM effort, is selecting the right people to facilitate the analyses. Your RCM facilitators will provide several key functions that will determine the future success of your RCM effort. As a result you should take some time and consider the following traits displayed by the best RCM facilitators.
1. Most important, your RCM facilitators should be driven and likable. A good personality combined will keep people on task and in the room. It should be a must that these people have shown the ability to facilitate an orderly meeting.
2. Your facilitators should be highly motivated self starters who have a vision for what the future of maintenance should look like. Your RCM analyses will take some time to complete and implement so your facilitators will need the strength and patience to continue to push forward towards that future vision.
3. Your facilitators should have a good knowledge of several trades, electrical, mechanical, instrument, and pipe. While it’s not required to be an expert in each, the more you know of each the better off you are as a facilitator.
4. Your RCM Facilitators should have a thorough understanding of Reliability and the use of different Reliability Tools.
5. Your RCM Facilitators should be highly respected by their peers. If you can select your facilitators from within the organization they will have credibility from the start and won’t have to spend time building it.
Companies with successful RCM efforts take the time to use a process for selecting their RCM Facilitators.
Tip provided by Doug Plucknette
Reliability Solutions
Tel: 585-349-7245
http://www.reliabilitysolution.com
October 20, 2005
Motor Testing Tips
Finding Broken Rotor Bars
Broken rotor bars and cracked end rings are issues every predictive maintenance technician faces at some time. There are several sophisticated technologies that can be employed to diagnose rotor bar issues including dynamic testing and vibration analysis, but there is a simple technique anyone can use that works quite well (assuming the rotor is not “skewed”).
Apply a single-phase voltage equal to approximately 25 percent of the nameplate voltage and monitor the current of one phase as you slowly turn the rotor. The current will remain reasonably steady as the rotor passes through the magnetic field until it passes the broken bar. At that time, the current will drop decisively since that bar is not capable of conducting current. Once the broken rotor bar has passed through the magnetic field, the current will quickly return to the same level it was tracking.
Tip provided by Baker Instrument
Tel: (800) 752-8272
http://www.bakerinst.com
October 20, 2005
Vibration Analysis Tip
If there is a dramatic change in the amplitude of your vibration readings, a rotor rub could be the suspect. A rubbing rotor may change the stiffness of the rotor, thereby changing the natural frequency. The equipment may now be running in a resonant condition due to this change in natural frequency.
Tip provided by LUDECA, INC.
ALIGNMENT * VIBRATION * BALANCING
http://www.ludeca.com
Tel: 305-591-8935
October 13, 2005
Everything You’ve Wanted to Know About Oil Analysis - Pre-Conference Workshop
LubricationWorld - Collocated with
The 20th International Maintenance Conference
December 6-9
Tampa Florida
Certificate Workshop led by Ray Thibault, CLS, OMA and Kevan Slater and Paul Goldman and Ray Dalley
Dec 6
8:00 am - 3:30 pm
A one day comprehensive oil analysis workshop will give you the essential knowledge to understand how to optimize equipment reliability and lubricant life through the proper use of oil analysis.
We have brought together a team of oil analysis experts for the workshop to provide you with the latest techniques in understanding and effectively using oil analysis.
The following are a list of topics which will be covered:
• General Introduction and Oil Analysis Testing Techniques - Ray Thibault – LTC
• Proper Sampling Techniques and Hardware- Kevin Slater- Schematic Approach
• Wear Debris Analysis- Ray Dalley- Predict
• Procedures to Properly Set Up an Oil Analysis Program – Paul Goldman – MRT
• Report Interpretation- Panel
• Question and Answer- Panel
LubricationWorld and IMC-2005 include over 14 full day workshops, 50 short courses and learning zone sessions and over 100 solution providers.
Please call toll free (888) 575-1245 in the US or…
October 13, 2005
Motor Testing Tip
Synchronous Motor Testing
One of the most challenging areas to test on a synchronous motor are the rotor coils. Traditionally, the most effective method was to apply AC voltage (normally 120 Volts) across the coils and measure the voltage drop across each coil. Variations greater than 5% are considered poor and the coil(s) can be replaced. The problem has been the danger of applying the AC voltage, the requirement to disassemble the machine and time.
Modern Motor Circuit Analysis (MCA) technology utilizing phase angle (Fi) and current/frequency response (I/F) can provide a rapid fault detection. With this MCA test, all testing is performed directly through the stator windings. When testing, if the Fi phase tests vary more than +/- 1 point from average and/or the I/F phase tests vary more than +/- 2 points from average, turn the shaft at least 10 degrees. If the test results rotate, then a short exists in the rotating fields. If the test results show the original pattern, then the fault exists in the stator.
Once a fault is detected in the rotating fields, in order to detect which coil(s) are bad, an MCA impedance test is performed across each coil. Any impedance more than 5% different from an average coil indicates a shorted coil. While it is recommended that all of the coils are rewound, replacement of bad coils can allow the machine to be operated through to a planned shutdown.
Tip provided by ALL TEST Pro
http://www.alltestpro.com
Tel: 800 952-8776 or 860 395-2988
October 13, 2005
Integration: A Reliability “Buzzword”?
We seem to be hearing more talk about “Integrated Reliability” – why?
DMSI has prepared a short article that explains why and breaks down the elements of an integrated reliability program. Learn about integrated reliability to ensure you make the correct choices.
Click here if you would like more information or to download the presentation
October 13, 2005
Root Cause Analysis (RCA) Tip
IS RCA INDUSTRY SPECIFIC?
Many people believe that their choice of RCA methods will vary depending on the industry they are in. These people do not realize that true RCA has nothing to do with the environment, but its common denominator is the human being. The nature of the event is irrelevant. What is important is the logical, deductive discipline of the human thought process. The same thought process will be used whether a person is investigating an explosion of a crude unit in a refinery or an unexpected death in a hospital.
Tip provided by the Reliability Center Inc.
http://www.reliability.com
Tel: 804-458-0645
