When using airborne ultrasound to record readings for trending such as bearing readings, be sure to use the same instrument and serial number of both the ultrasonic receiver and contact probe. Some of the ultrasonic instruments in the marketplace are not "repeatable" from one unit to another. If you lose or break a contact probe and receive a replacement, be sure to disregard those previous readings if the newer contact probe or instruments are not within an acceptable range of 2-3 db's. Some contact probes can vary widely. In other words you may or may not replace a good or failing bearing causing an unexpected downtime. If multiple models exist within your plant be sure to compare the readings to a known source and record those readings for reference.
Tip #2 - Ask your Ultrasonic vendor about repeatability!
Tip provided by Ultra-Sound Technologies, LLC
http://www.ultra-soundtech.com
Tel: (770) 517-8747 Phone
Find a one day Airborne Ultrasonic Workshop near you
The slickest way to correct for softfoot is illustrated in "Shaft Alignment Handbook", Second Edition by Peter Piotrowski.
This method uses stainless steel shims modified in one of the following shapes:
Full Shape - unmodified
L Shape - One leg cut off
Front Side - Cut off both legs
One Leg - Separate a full length leg from full shim One Corner - one corner of a One Leg shim With these shapes, any soft foot can be eliminated with a minimum of shimming. This technique minimizes the chance of developing "squishy foot".
The first step is to measure each foot with a feeler gauge at the 4 corners. Using the example in the book, we'll shim one foot. The measurements are:
A= Inside Left = 0.012"
B= Inside Right = 0.024"
C= Outside Left = 0.018"
D= Outside Right= 0.030"
Find the smallest reading which is 0.012" at "A".
Add a 0.012" Full Size shim under the foot.
Subtract 0.012" from all the measurements.
A = 0.012" - 0.012" = 0
B = 0.024" - 0.012" = 0.012"
C = 0.018" - 0.012" = 0.006"
D = 0.030" - 0.012" = 0.018"
Again, find the smallest reading greater than 0. This time it is "C" at 0.006".
Since "A" is already = 0, no shim is needed at this location. All the other locations will benefit from a 0.006" shim. This new shim will be an "L" shaped shim with the part of the leg under "A" cut off.
Subtract 0.006" from all the readings greater than 0 A = 0 B = 0.012" - 0.006" = 0.006"
C = 0.006" - 0.006" = 0
D = 0.018" - 0.006" = 0.012"
The smallest reading greater than 0 is "B" which is 0.006"
A 0.006" shim is added under "B" and "D" by cutting a One Leg shim.
Subtract 0.006" from the values greater than 0.
A = 0
B = 0.006" - 0.006 = 0
C = 0
D = 0.012" - 0.006 = 6
"D" is the only shimming left. A One Corner 0.006" shim is placed at "D".
This completes shimming at this foot. Shimming the other 3 feet is a repetition of these steps.
Tip provided by Jon McFadden
Vibration Analyst
Kimberly-Clark Corp.
Purchase the Shaft Alignment Handbook by John Piotrowski
March 9-11, 2005
Clearwater Beach, Florida
Time is running out to register for the most important RCM focused event of 2005!
The Reliability Centered Maintenance Managers' Forum is a focused RCM event where maintenance and reliability professionals learn from each other through a series of informative learning sessions, short courses, networking opportunities and an optional full day workshop.
Participants will discover exciting new ideas and learn helpful techniques for implementing or improving reliability centered maintenance.
• Learn everything you need to build a world class Reliability Centered Maintenance Program
• Discover exciting new ideas and learn helpful techniques to jumpstart your Reliability Centered Maintenance program
• Learn how Maintenance & Reliability Professionals just like you are creating results with RCM
• Meet leading RCM service providers
• Learn how to track and report the business improvement results of your RCM program
To register please call 239-985-0317 or...
Many motor management programs focus on: Energy efficiency; Repair vs replace decisions; Maintenance and Predictive Maintenance; and/or, Motor storage. However, few focus on motor life and reliability.
The objective of any true motor management program is to extend the effective useful life of the motor system combined with continuous improvement of the system. This includes:
• Energy improvements
• Motor system maintenance
• Motor system reliability
• Repair vs replace decisions
• Covers the incoming power to the driven load
Definition: Motor system maintenance and management is the philosophy of continuous improvement of all aspects of the motor system from incoming power to the driven load. It involves all components of energy, maintenance and reliability from system cradle to grave.
Tip provided by
Howard W Penrose, Ph.D.
T-Solutions, Inc.
http://www.tsoln-inc.com
Tel/Fax: 860 577-8537
More Motor Management Resources
Delivering Basic Care Information to Operations Staff
One of the keys to success in developing an asset basic care system is to have operations and maintenance work together to develop information collection and reporting procedures that both can live with.
Often, operations have a well-developed system in place to view plant status, using systems such as HMI (human-machine interface) displays and plant data historians (like PI from OSISoft). Acceptance of an electronic asset basic care program can be greatly increased if the data being collected by handheld computer can be automatically routed to the operator's data system.
One oil refinery converted a very extensive paper-based inspection to an electronic asset basic care program. One of the primary goals was the ability to automatically deliver the asset status information to the operators via their control room software. This was accomplished using information directly collected from handheld electronic units. This allowed the operators to get immediate access to basic care findings without generating and reading reports, or by looking up status information in another software package.
This tip provided by Design Maintenance Systems Inc.
DMSI
http://www.desmaint.com
Canada Tel: (604) 984 3674
Download an Asset Basic Care Presentation from DMSI
Combined Companies Launch
On January 18, 2005, Oracle announced, at an event at its headquarters with more than 48,000 joining by Webcast and phone, how the nearly 50,000-strong combined workforce of Oracle and PeopleSoft will provide unparalleled innovation and support to 23,000 applications customers throughout the world.
Spectrum vs. Cepstrum
When a spectrum contains several sets of sidebands or harmonic series, it can be confusing due to the overlap. Try using a Cepstrum. A cepstrum is a spectrum of a spectrum. In the cepstrum, they will be separated in a way similar to the way in which the spectrum separates repetitive time patterns in the waveform. Try using a cepstrum on your Gearboxes and rolling element bearings.
Tip provided by LUDECA, INC.
Distributor of the new VIBXPERT data collector/vibration analyzer
http://www.ludeca.com/vibxpert.htm
Tel: 305-591-8935
Download the Taking Accurate Vibration Measurements Case Study at Ludeca.com
Understanding and using inductance measurements:
If you measure the inductance of a 3-phase motor with the rotor removed the measurements should be balanced. In an assembled motor, mutual inductance between the stator and rotor causes the inductance to increase. Depending on motor design, there may be an inductance unbalance between phases that can be 20% or higher. Moreover, the measured inductance of each phase and the amount of unbalance will vary with the position of the rotor.
By measuring inductance at 24 or 36 equal rotor positions on all three phases through 360 degrees of rotation, and graphing the results, rotor health can be evaluated for conditions including broken rotor bars, high resistance joints and eccentricity (rotor air gap).
However, since many motors will exhibit inductance unbalance and this unbalance can change with rotor position, inductance alone is a poor indicator of winding health. In Addition, most winding faults in a 3-phase motor will not show a significant inductance unbalance until the winding has developed a short.
Static inductance measurements when combined with impedance measurements from a low-level sine wave instrument are useful for detecting either contaminated or over-heated windings.
Tip provided by ALL-TEST Pro, A Division of BJM Corp
http://www.alltestpro.com
Tel: 860.399.5937
Don't miss this opportunity to spend three focused days in the wide world of Reliability Centered Maintenance.
Reliability Centered Maintenance Managers' Forum
March 9-11, 2005
Clearwater Beach, Florida
• Learn everything you need to build a world class Reliability Centered Maintenance Program
• Discover exciting new ideas and learn helpful techniques to jumpstart your Reliability Centered Maintenance program
• Learn how Maintenance & Reliability Professionals just like you are creating results with RCM
• Meet leading RCM service providers
• Learn how to track the results of your RCM program
It is Spring Break in Florida and Clearwater Beach Hotels are filling up fast - so please register today at 239-985-0317 or...
How to avoid CMMS/EAM System Failures
Failure #9 Inadequate training/documentation
Many companies will still purchase software and try to “learn by the manual.” This is a very costly and time-consuming way to learn how the software functions. It is best to have the vendor’s training personnel train your people. If you allow your people to flounder or to let the vendor’s programmers train your people will spell sure disaster.
It takes a certain type of person to train for software use, and part of the selection process should include the evaluation of the vendor’s training personnel. Again, reviewing the training programs of Companies already using the software will ensure the program produces satisfactory results. Training and documentation also suffer when Companies try to reduce the cost of system implementation. One of the first areas they reduce is the amount of training or the number of sets of documentation. This practice results in poor utilization of the system.
Tip provided by GenesisSolutions
Terry Wireman, CPMM
Tel: (203) 431-0281
http://www.GenesisSolutions.com
iPresentation Tutorial Invitation: Conducting an Effective EAM/CMMS Training Program
Software giant SAP (sap.com) is intensifying its focus on the Enterprise Asset Management (Maintenance Management) market.
With the broadest solution for EAM currently on the market, SAP and partners are introducing new functionality in the areas of:
• Planning and Scheduling
• RCM support and integration with the Work Identification – Execution cycle
• Fully integrated Maintenance Cost Budgeting and analysis
• Role-based intuitive portals ensuring easy transaction and information access with visibility on asset condition
• EAM Business intelligence solutions
SAP’s Service and Asset Management unit is taking an aggressive approach to push SAP’s market leadership in this area. As they have shown in CRM (where SAP has now toppled Siebel as market leader), when SAP focuses its attention on a market, its only a matter of time.
Evidence of this new intensity comes in the SAP-centric EAM conference running in Tucson, AZ from March 20-23, 2005 [ www.sap-centric-eam.com ]. Organized by event experts Functional Asset Solutions in conjunction with SAP, this event features impressive content from SAP customers in North America, updates on strategic plans from SAP’s Service and Asset Management Unit and showcases new EAM functionality from SAP and its technology partners – NRX, Meridium, Impress and more. The show is rounded out with the key service providers around this space – the “globals” - Accenture and IBM and specialist players such as New Dimension Solutions.
One senses that the SAP juggernaut is rolling in EAM. EAM business processes run across the enterprise – work management touches financials, HR/HCM, materials management/SCM, customer service/CRM and really every part of the enterprise making SAP’s vaunted integration all the more important. SAP’s best-of-breed competitors have relied on slinging mud around usability and esoteric maintenance/reliability functionality. Given these new offerings it appears that SAP has closed any apparent chinks in its armor in these areas and offers huge advantage to new and existing customers in the depth and breadth of value in terms of license fees.
We suggest you kick the tires and the winter blues in Arizona in March – this looks like a very interesting event in a lovely corner of the country (especially in March!)
For more information please visit the conference website at http://www.sap-centric-eam.com or call us at 914-509-5355.
Learn More about the SAP-centric EAM conference online
Motor Overheating in VFD Applications
Overheating is one of the primary causes of early motor failure. Variable frequency drives (VFDs) generate pulse width modulated output signals rather than smooth sinusoidal waveforms. The extra harmonic content in these signals is dissipated as heat within the motor. In fact, a VFD driven motor running at nameplate frequency and load will run 10C hotter than the same motor driven by a sinusoidal source. One approach to this type of problem is to derate the motor to compensate for the harmonic heating. Another is to specify an “Inverter Duty” motor.
VFD applications running at frequencies less than nameplate (lower speeds) present another problem; internal fan speed is reduced, resulting in increased motor temperature. Once again, derating may be required to compensate for the increased temperature. Or the addition of an external fan may be necessary. Additionally, some drive manufacturers provide tables to help match a drive to a motor for a particular application.
Tip provided by Baker Instrument
Tel: (800) 752-8272
http://www.bakerinst.com
A hazardous environment, as defined with regard to a combustible atmosphere, is one that could burn explosively with the addition of energy sufficient to cause ignition. Hazardous environments are broken down into categories by the National Electrical Code in order to define conditions that can cause ignition of the combustible atmosphere. These categories include combustible gases and suspended dust and particulate. Equipment can be evaluated and certified as Intrinsically safe for operation in various hazardous environments.
Some vibration monitoring applications require the transducer to be installed in a hazardous environment. In these applications, the transducer must be unable to ignite the surrounding atmosphere. A transducer that is intrinsically safe cannot develop enough energy – either through heat energy, or through spark energy – to ignite the hazardous environment, whether operating normally or under fault conditions. A transducer approved as Intrinsically Safe can be installed directly into the hazardous environment.
To learn more about hazardous environments, or Intrinsically Safe vibration monitoring, go to http://www.wilcoxon.com
Download the Vibration Calculator
A Distance Learning Course by Steve Thomas
Companies initiate change programs all of the time. Some succeed but many more fail to accomplish their stated goals. Previous failure can make future efforts even more difficult due the audience becoming skeptical.
Of all types of change, reliability focused efforts are perhaps the most difficult to initiate and conduct. These initiatives often meet significant resistance because there are always those who did well working in a reactive maintenance environment. Lukewarm support is often the most that can be expected from those changing to the new reliability based approach. How a manager manages the change will be the difference between success and failure.
This course teaches the basic skills required to break down the barriers encountered by reliability focused change efforts.
The next course begins on April 1, 2005 - Register today as number of students is limited.
To register or learn more about courses please email: info@masteringmaintenance.com or call toll free (888) 230-5280 or...
Thermographer’s Checklist.
Do you have what you need when you go in the field? It is always better to be prepared then to be caught with unexpected “surprises” in the middle of an inspection.
It is a good idea to create a Thermographer’s checklist and keep this handy. Stick it on your wall, put it on your desk, input it in your PDA, or post it somewhere close at hand.
Some examples:
• Plenty of charged batteries! Make sure that you are prepared the night before with your batteries and make sure to have enough to last.
• Free space on your digital media. Whether your system has Flash Cards, CF, SD media, or on board storage, make sure that you have enough space for your day of data collection.
• Digital camera (and batteries.) Many IR cameras these days have visual cameras built in (some with flash capability.)
• Voice recorder or a place to take notes. Again, many thermography systems have on board voice storage as well as method to take notes (i.e. via a PDA). Otherwise, you can always bring a note pad!
• A route list of what needs to be inspected. If your IR system has a PDA, you can upload this directly into your camera.
• Proper protective gear and safety apparatus. Make sure to bring your hard had, safety glasses, gloves, and whatever else you require.
• Lenses? Perhaps you have long distance or wide angle applications and need additional optics. Check with your manufacturer.
• Any authorization forms.
If you plan ahead, you can certainly save time in the long run.
This tip provided by Electrophysics
Manufacturer of EZTherm and EZTherm Pro Cameras
http://www.electrophysics.com
Tel: 973-882-0211
Check Out The Technology Overview for Microbolometer Detectors by Electrophysics
If jackscrews are not available to move a machine laterally, consider using a pair of large carpenter's pipe clamps, tensed against each other and the base. This way you can carefully and precisely control the movement of a machine without having to hit it with it a hammer. However, if hit it you must, then use a shot-loaded, deadblow hammer and never a steel-faced sledge hammer. Again, this will help to protect the machine and you can control the move better while using lighter blows.
Tip provided by LUDECA, INC.
Distributor of the new Optalign PLUS Series 'Modular' Shaft Alignment System
http://www.ludeca.com
Tel: 305-591-8935
Precision Shaft Alignment: What's the right method for you?
Jacking Bolts
If using jacking bolts for your side-to-side corrections, always remember to back off the jack bolts on the opposite side. Remember that once you are done with your side-to-side correction, we recommend to always back off all jackscrews after the alignment is completed and the anchor bolts are tight. If movement is known to occur, it will always be in the path of least resistance, which can be targeted for.
Tip provided by LUDECA, INC.
Distributor of the new ROTALIGN ULTRA alignment system http://www.ludeca.com/ultra.htm
Tel: 305-591-8935
Please visit Ludeca's Case Study Library
How to find hot spots faster
In this day of fairly sophisticated thermal imaging systems, all with numerous features and benefits, sometimes the basic concept of how to most easily find hot spots eludes many thermographers. Some folks prefer to utilize color palettes when they perform surveys, others prefer to utilize black and white. One popular alternative is to utilize what some people call the “highlight” palette, or a fashion of this.
Basically, this is a black and white palette which either has the pure white, which represents the hottest parts of the image replaced with a solid color. Typically this is red. Alternately, the coldest parts of the image are typically indicated with a different color, usually blue. (In addition, the operator can place a colored isotherm on a black and white image to have the same effect.)
The operator then can change his settings so that the colored part of the image (red-hot) will be slightly higher than ambient, or a suitable reference. An example: if one was looking at an electrical panel and the panel was, in general 95ºF, then the operator could set the highlight to be at 96ºF. Therefore, only hot spots above 95ºF will appear to the operator as distinct color on a black and white background.
This allows the operator to quickly locate hot spots and focus in on the problems.
This tip provided by Electrophysics
Manufacturer of EZTherm and EZTherm Pro Cameras
http://www.electrophysics.com
Tel: 973-882-0211
Check Out The Infrared Imaging Tutorial by Electrophysics
CMMS/ EAM requirements for Utilization
This maintenance tip focuses on what is required for a CMMS/ EAM system to be fully utilized. The first consideration for full utilization is accurate data loading of the CMMS/ EAM system databases. Even as a company implements a CMMS, data collection begins. Consider the various modules used in a comprehensive CMMS/EAM System:
Equipment
Inventory
Purchasing
Personnel
Preventive maintenance
Work order
Reporting
The equipment module. To use this module properly, a company must identify each piece of equipment—or facility location—that they want to track costing and repair information. For example, when making repair/replacement and other cost decisions, they need the financial information stored in the equipment history. Data entered into other system modules will ultimately determine the accuracy of the financial information.
The inventory module. This module requires the identification of the spare parts carried in each store at the plant or facility to use this module. The necessary data required includes, but is not limited to:
• Part number
• Part description (short and extended)
• On-hand, reserved, on-order, max-mm, etc.
• Locations
• Part-costing information
• Historical use.
Information from the inventory module ensures the CMMS/ EAM System will contain accurate material-costing information for each piece of equipment or facility location.
The purchasing module. This module is associated with the inventory module, and it provides the maintenance planner with a window into the ordering information. What is some of the information this module must include?
• Part number
• Part description
• Part-costing information
• Delivery information, including the expected delivery date
• Related vendor information
• The ability to order non-stock materials.
The importance of this module becomes clear when the planner begins to plan a job and does not know when they will receive the part. Also, this module is important for estimating job cost since it provides the new part cost.
It is quickly apparent that without accurate data loading in these modules, the CMMS/ EAM system will not be fully utilized. This topic will be explored further in part 2 of this Maintenance Tip.
Tip provided by GenesisSolutions
Tel: (203) 431-0281
www.GenesisSolutions.com
iPresentation Invitation: Successfully Selecting, Implementing and Utilizing CMMS/EAM Systems
VibrationSchool.com offers a 100% free short course "Introduction to Vibration Analysis" course based on the popular V-Trainer Vibration Analysis Training Course on CD-ROM.
Hydraulic Cylinder Leaks – Leaks inside rams are often the result of contaminated hydraulic fluid. Particles lodge themselves between the wiper and the cylinder wall eventually causing the seal to fail and the cylinder no longer holds its pressure. Ultrasound inspectors are trained to pinpoint these internal leaks using either contact stinger probes or magnetic sensors. Under pressure, a good cylinder should be quiet while in a leaking cylinder hydraulic fluid will pass the seal at the point of the breach creating gurgling, popping, or swishing sounds. Adjust the sensitivity of the detector to the highest level possible and position the magnetic sensor or contact probe in the approximate area of the ram’s wiper. Be sure to listen on all sides of the cylinder to ensure nothing is missed. Identifying hydraulic leaks ultrasonically can save several hours of labor by directing the repair to the correct area quickly.
Tip provided by SDT North America
Toll free: 1-800-667-5325
Tel: 905-349-2020
Join the International Ultrasound Users Group
"That's the way we have always done it!" is a common refrain when asked why a great deal of maintenance work is done the way it is.
With RCM you will practice a detailed process that will ensure you are doing the right work to increase reliability and safety. Most of the time you will find that a maintenance program based on Reliability Centered Maintenance will actually reduce cost and increase availability over time as well.
Take three days to immerse yourself and your team in the world of Reliability Centered Maintenance with 12 Real World RCM Case Studies, a Reliability Incident Management Short Course and the new RCM Scorecard Workshop. The Reliability Centered Maintenance Managers' Forum will jumpstart your journey to an improved maintenance program.
Please join us on March 9-11 at the Sheraton Sand Key resort in beautiful Clearwater Beach Florida. Register before February 11 to take advantage of great hotel discounts. Call 239-985-0317 to register for The Reliability Centered Maintenance Managers' Forum or...
Register for the Reliability Centered Maintenance Managers' Forum online
Motors powered by PWM drives can develop “pinhole” shorts in the windings. These faults will cause the drive to trip and can often be a challenge to detect and confirm. For example, conventional measurements of winding resistance using a digital multimeter and insulation to ground resistance using a meg-ohm meter will give acceptable readings. When the drive is put in bypass mode the motor will often operate on line power. As a result the fault is often mistakenly diagnosed as a drive problem.
Testing with Motor Circuit Analysis can detect these faults. They will appear as unbalanced measurements in either phase angle or current frequency response. Quickly and positively detecting or ruling out these faults can save hours in diagnostic time, and avoid the lost production time and costs associated with making a wrong call.
Tip provided by ALL-TEST Pro, A Division of BJM Corp www.alltestpro.com
Tel: 860.399.5937
Understand How Your Equipment Fails
We frequently hear folks say, “If only I knew the MTBF of my equipment I could set up a PM to repair or replace it before it breaks.” True, it is important to understand the frequency of your failures, but it is just as important to understand what type of failures you are having.
Failures fall into three basic categories; infant, random, and Wearout. Maintenance policies based on frequency alone have a high probability of failures. Why? Because a large portion of the equipment population fails in ways that make time based replacement or overhaul are counter productive.
Infant failures are caused by some quality issue related to spares quality, quality of maintenance, or quality of operation. Time based replacement or overhaul in this case will actually induce failures in the system.
Random failures occur at a constant frequency that is not related to time in service. Time based replacement or overhaul in this instance is ineffective at preventing the occurrence of failures. For random failures there is a 63% chance that a failure will occur before the MTBF.
Tip provided by Bill Keeter, CMRP
ARMS Reliability Engineers - USA, Inc.
Tel: 888-673-8360
www.armsus.com
Download a short presentation on Understanding Weibull Failure Characteristics
Correctly Identifying Turnaround Issues Maximizes Value of Fluid Analysis Results
The value of fluid analysis results diminishes significantly with time as the condition of both the fluid and the equipment being testing continue to change. As a result, turnaround time is often the number one priority when it comes to choosing a testing facility. But if and when turnaround becomes a problem, how do you know where and with whom the real issues lie?
Ask yourself the following questions and find out if you’re doing all you can to identify those issues AND resolve them.
• Are you setting sampling schedules, sticking to them and effectively training everyone involved in the process?
• Are you taking good samples at the right time and providing your laboratory with complete and accurate information?
• Are you sending samples to your laboratory the day they’re taken via a trackable shipping service?
• Does your laboratory share in the responsibility for maximizing turnaround?
Tip provided by POLARIS Laboratories
Tel: (317) 808-3750
www.polarislabs.com
http://www.polarislabs1.com/fluid-analysis-turnaround.htm
Improving vibration sensor performance
For magnetically mounted accelerometers, keep your magnets clean and free from metallic chips with the use of the sticky side of Duct Tape or packaging tape. Removal of this debris will improve sensor performance. Occasionally, rub your sensor magnet on 400 to 600 grit sandpaper to remove any high spots, this will maximize the contact area, thus improving the sensor performance.
Tip provided by LUDECA, INC.
Distributor of the new VIBXPERT data collector/vibration analyzer
www.ludeca.com/vibxpert.htm
Tel: 305-591-8935
http://www.reliabilityweb.com/forms/ludeca1_reg.htm
The new Des-Case® Disposable Steel Breather is the ideal desiccant breather for mobile equipment. With 1-micron filtration and a rugged metal housing, the DC-DS breather is durable, resistant to vibration, and can withstand high temperatures.
The unit is available with several adapter options, including a proprietary design feature for extreme humidity and high outflow applications, which creates a virtually sealed system.
By prohibiting entry of dirt and moisture, mobile equipment operators can attain significant cost reductions. Not only from extended oil drain intervals, but through prevention of premature component failure and by limiting rebuilds.
E-mail Des-Case: breathe@des-case.com or...
http://www.des-case.com/DCDS_tech.pdf
High-Frequency VFD Application Issues
Modern variable frequency drives (VFDs) contain insulated gate bipolar transistor (IGBT) output devices. The switching action of the IGBTs generates waveforms with very fast rise times, increasing the possibility of over-voltages, electromagnetic interference (EMI) and bearing currents.
Impedance mismatches between motor windings and cable leads in a VFD application may result in waves that are reflected at the motor terminals. These reflections produce peak voltages that are nearly twice the magnitude of the inverter output voltage. This is especially true for long cable runs. Over time, the constant over-voltage condition may degrade motor insulation. Decreasing lead lengths, or applying motor terminal filters, inverter output filters or series reactors between the inverter and the motor terminals may alleviate the problem.
Fast switching IGBTs generate oscillatory currents at frequencies up to several megahertz, radiating EMI that can interfere with other electronic equipment. This EMI can also be conducted from the VFD back to the power source. Radiated EMI may be reduced by installing a common-mode choke or transformer between the inverter and the motor, and by bundling the ground wire with the phase leads. A common-mode choke or transformer installed between the power source and the inverter may reduce conducted EMI.
High-frequency inverters induce large voltages on a motor shaft. These voltages result from electro-static coupling between the rotor and stator windings, where normal bearing grease insulates the inner and outer races. Charge can accumulate on the shaft and eventually discharge through the bearing. Over time, these discharges damage a bearing, pitting balls and races. Mitigation techniques include a shaft grounding brush, ceramic bearings or conductive grease.
Tip provided by Baker Instrument
Tel: (800) 752-8272
www.bakerinst.com
http://www.bakerinst.com/BIC_Web/FAQs/FAQ_Low_Voltage_Compacitance_vs_AWAIV_Meg_ohm.htm
Operations and Maintenance Working Together?
A key point to successfully developing an asset basic care system is to have operations and maintenance work together to develop information collection and reporting procedures that both can live with.
One of the quickest ways to turn off operators is to present basic care information strictly through a maintenance point of view. If operators are given exception reports that are built solely to meet the needs of maintenance planning and scheduling, they will quickly conclude that they are carrying out the data collection work for the maintenance and reliability group.
Its important to sit down with the operators while the basic care program is being designed, to understand just what information the operators want to see in their basic care reports. Often, operators want reports that contain the same data as the reports received by maintenance, but formatted and ordered in different ways.
If your basic care data collection system is manual (pen and clipboard), and the reporting is being done by spreadsheets, make sure that the data entry spreadsheets are designed to allow multiple other spreadsheets to access the data for reporting.
If your basic care data collection system is electronic (using handheld computers), it's helpful if your software system has a built-in report editor, to allow different report formats to be derived from the same data.
This tip provided by Design Maintenance Systems Inc.
+1 604 984 3674
www.desmaint.com
http://www.desmaint.com/contactUsAssetBC1.html
Improved technique for temperature measurement of electrical anomalies.
As a practicing thermographer I like to employ a technique that we at Colbert Infrared Services refer to as “squeezing”. The squeezing technique has several advantages in allowing you to better diagnose the problem, while obtaining the hottest temperature of the fault.
The first step in this procedure is a firm ability to adjust the infrared imaging device using the sensitivity and level, not just hitting the auto adjust button. While looking at the electrical problem, the thermographer uses the level and sensitivity to adjust the infrared camera so the electrical component and the hot spot have the highest thermal resolution possible.
For example, when using the gray scale pallet (where white is warmer and black is cooler), the thermographer would adjust the camera so that the entire temperature scale or color bar is used to zero in on the hot spot and electrical component.
In doing so, the hot spot would appear white or light gray and the electrical component would appear dark gray to black. This would also result in the background appearing black because its temperature would be below the lowest part of the temperature scale.
The thermographer would then bring the level up just a little bit more until the hottest spot is brought into the mid grey level then change the viewing angle to see if you could see the hot spot getting lighter in color indicating a warmer area of the hot spot.
It is very important to not just move the camera side to side while changing viewing angles but to also move the camera angle up and down while viewing the hot spot. If after changing the angle you see the hot spot getting saturated white, continue adjusting the camera as above until a point when you change angles you do not see the hot spot getting white. It is important to try and keep the sensitivity fairly narrow while locating the hottest area. The angle that the infrared camera is usually moved in is following the conductance pattern of the anomaly.
Now when you measure the temperature (using the proper emissivity) you know that you are measuring the hottest spot of the problem. The squeezing technique also allows multiple thermographers to obtain the same readings because it assures that the hottest spot is being measured.
Tip Provided by Tarry Wolfe, Colbert Infrared Services
Sales Representative for Mikron Infrared, Inc.
http://www.irimaging.com
Tel: 888-506-3900
http://www.maintenance-tips.com/forms/mikron_request_2.htm
Deficient implementation planning
Implementing a maintenance system takes resources. These resources may be financial, if you are having the vendor or a consultant do it. Otherwise, your necessary resource will be labor from your staff.
Implementing tile systems takes time. It does not happen overnight. During the implementation, it takes labor to gather data and to input it. Failing to realize this, some managers have promised quick implementations and paybacks. When they could not deliver this, they were dismissed or transferred. Most vendors who have been in the marketplace for any time at all have documented implementation plans. Ask for copies of the implementation plans for review. By reviewing these plans, you will see how long the implementation should take for an organization like yours.
Tip provided by GenesisSolutions
Tel: (203) 431-0281
www.GenesisSolutions.com
http://maintenanceconference.com/cmms/
Overcoming a Common Barrier to Implementing a Reliability Improvement Strategy
“We don’t have enough resources to implement a reliability improvement project.”
It is a common problem in every maintenance organization. The assumption made by many maintenance managers and supervisors is that they do not have enough resources to implement a reliability improvement project. Our general nature is to focus our attention on things we are held accountable for. If management never asks, the level of effort expended on the project drops exponentially.
The answer - senior management needs to actively sponsor reliability improvement projects, providing adequate resources and exercising accountability. The strength of the business case will secure active management sponsorship. Properly structured reliability improvement projects achieve results quickly. Implementing first on the highest risk assets, payback is rapid, typically less than one year. Within three years, optimizing asset reliability typically realizes a return of 5 - 12 times the investment in the project. And allocating the required resources quite simply becomes a necessary part of the solution.
For change to take place energy must be put into the system and dedicated resources must be used to initiate the project. Fires are not extinguished over night. In the short term, we must continue fire fighting as well as initiate fire prevention (on a selected small subset of the asset base). Soon, the reliability improvement effort will pay off. System by system, the movement to a proactive, condition based approach to maintenance makes life better. Proactively managing equipment reliability is a logical, common sense approach to maintenance.
Tip provided by Ivara Corporation.
www.ivara.com
http://www.ivara.com/main.php?tID=1&sID=1&lID=0
PdM-2005
The Predictive Maintenance Technology Conference
September 19-22, 2005
The Atlanta Sheraton
Please consider sharing your success stories, knowledge and experience at the Predictive Maintenance Technology Conference by submitting your idea for a paper and presentation. The latest date for sending your idea for a paper is February 15, 2005.
This conference is a focused learning event people who work with:
• Vibration Analysis
• Infrared Thermal Imaging
• Airborne Ultrasonics
• Predictive Motor Testing
• Oil and Wear Particle Analysis
Speakers receive a VIP pass for PdM2005 at no cost. Submission of an abstract indicates the author’s commitment to attend and present the paper. Please do not submit an abstract if you cannot attend and present.
Successful authors will be notified by February 28, 2005, and will be sent manuscript preparation guidelines and conference registration information.
Email a paper title and 2-3 paragraphs about what will be covered and what the attendees will take away (learn) from the session to tohanlon@reliabilityweb.com or...
http://www.maintenanceconference.com/pdm/call_for_papers.htm
Measuring Lubrication film thickness in double-roll spherical roller bearings.
One of the most common bearing installation faults that affect lubrication film thickness is the installation and set up of the tapered bore, double-row spherical roller bearing using a split tapered adapter in a mounted unit, i.e. Pillow Block Bearing.
The tapered adapter is used as a wedge device to hold the inter race of the bearing on to the shaft. All bearing manufactures have recommended clearances for applying this type of bearing. This type of bearing in a pillow block housing is very common on larger fan applications and is a very popular style for many other applications.
If the tapered sleeve (adapter) is drawn up to far by over tightening the spanner nut (a very common practice) the internal clearance of the bearing will be removed thus reducing the lubrication film thickness. Even though these bearings are running with no apparent fault or vibration alarm detected by using normal FFT technology the reliability of the machine has been put into jeopardy because the operator cannot see the film thickness problem. Lubrication film thickness can be measured to determine the true condition of the bearing during start up without setting a baseline and treading. Differentiating bearing surface damage faults and lubrication film thickness faults is powerful knowledge.
Tip provided by John Phelps
SPM Instrument, Inc.
Tel: 541-687-6869
http://www.spminstrument.com
http://www.spminstrument.com/support/publications/articles/
DMSI has prepared a presentation and white paper to get you started on tracking ALL your lubricated assets and keeping them operating effectively. It’s based on the integration of lubricant management and analysis. All readers are invited to download the white paper and view the presentation online.
http://www.maintenance-tips.com/forms/dmsi_request.htm
Next Course begins February 1, 2005!
Join Vibrationschool.com instructors for a 8-12 week distance learning course that blends web based information, a V-Trainer CD ROM with actual case studies that teach real world problem solving skills, weekly assignments, self study assessment quizzes, and coaching via email.
http://www.vibrationschool.com/distance_course.htm
As Eli Goldratt stated in "The Goal", an expert is not someone that gives you the answer, but rather someone that asks you the right questions. This concept is relevant in RCA because one of the greatest values of RCA, is the learning by the team members when they have to ask the right questions, and search for the answers themselves. RCA approaches that provide the answers (which they cannot possibly provide all the answers, everywhere), eliminate the element of learning derived from RCA. This all depends on what the goals of the organization's RCA efforts are.
Tip provided by The Reliability Center
www.reliability.com
Tel: (804) 458-0645
http://www.reliabilityweb.com/forms/proact_reg.htm
RCM-2005
March 9-11, 2005
Clearwater Beach, Florida
Tel: 239-985-0317
What’s included in a 3 day RCM-2005 pass:
• 1 – Full day RCM Scorecard Workshop
• 12 - RCM implementation Case Study Presentations
• 2 hour Reliability Incident Management short course
• Free Welcome Cocktail reception
• RCM-2005 Dinner banquet
• Breakfast for 3 days
• Lunch for 3 days
• Free Internet Computer Stations
• Prize Drawings
• CMRP Certification Opportunity
Plus Valuable Take Home Tools:
• RCM-2005 Printed Proceeding Book
• RCM-2005 Proceedings CD including slide presentations
• RCM Scorecard Manual
• RELIABILITY Magazine Copy
• Audio CD Interview with Mac Smith Co-Author of RCM: Gateway to World Class Maintenance
• Nowlan & Heap’s original RCM report on CD ROM
• Navair, NASA and Corp of Engineers RCM Manuals on CD ROM
Jumpstart your maintenance program. Learn what works – learn what doesn’t in the complex world of Reliability Centered Maintenance from experienced people who have already made the journey.
Please call 239-985-0317 to register or…
http://maintenanceconference.com/rcm/
When using Induction Heaters to heat bearings, make sure that the tops of the vertical post are clean; this will make for better contact of the horizontal crossbar. Applying a thin coat of the petroleum jelly will also help. This prevents vibration from occurring and possibly false brinelling the work piece being heated.
Tip provided by LUDECA, INC.
Distributor of the EDDYTHERM bearing heater http://www.ludeca.com/eddytherm.htm
Tel: 305-591-8935
http://www.ludeca.com/eddytherm.htm
Simplify Thermography Electrical Inspections
There are a few basic aspects of thermal problems you want to capture while out in the field. First, get the best thermal image you can.
• Check to see you have the correct image composition?
• Can you see the hot spot with enough resolution; are other phases or other reference points within the frame needed?
• Are you close enough to make a reasonable measurement?
• Check with the vendor about the distance to spot size specification?
• Is the temperature scale set properly?
Most cameras have an auto exposure setting. In some cases a hotspot is so severe that the automatic exposure will select the lowest gain resulting in an image with little contrast. Better to let cooler portions of the image go out of range then hot areas.
Don’t set emissivity value below 0.5. While all systems allow lower settings most users will not be able to make an accurate measurement due the complex nature of shiny objects.
Record the load. After finding a hotspot it is critical to understand the severity of the fault. A 5° temperature rise at 5% load maybe more critical than a 50° C rise at 100% load. Check the load.
Tip provided by Electrophysics
Manufacturer of EZTHERM Cameras
www.electrophysics.com
973-882-0211
http://www.electrophysics.com/Browse/Brw_ProductLineCategory.asp?CategoryId=96&Area=IS
When kitting and staging parts for jobs, it is very helpful to attach a tag with the work order number printed clearly on it to BOTH the equipment and the kit. This makes it easy for the craftspeople to match the parts with the job. Bright orange tags work especially well.
Tip from 5 Pillars: Maintenance & Reliability Professional Review Course
MasteringMaintenance.com
Toll Free: 888-230-5280
http://www.masteringmaintenance.com/DK0411.htm
Selecting Range of 4-20 mA Velocity Transducers
In selecting a 4-20 mA velocity transducer, ideally the user should be able to answer the following three questions:
1) What is the normal overall vibration level of the machine?
2) What is the limit for unacceptable vibration?
3) Is over-range capability for trending desired?
If the user does not have answers to any or all of these questions, the ISO standard can be of assistance in determining the best 4-20 mA velocity transducer. Smaller machines (under 100 HP) can likely be monitored using a full-scale range of 0.5 IPS peak to cover most monitoring and trending needs. Machines over 100 HP would usually be best monitored using a transducer with a full-scale range of 1.0 IPS peak.
Tip provided by Wilcoxon Research, Inc.
Toll Free: 1-800-945-2696
Tel: 301-330-8811
http://www.wilcoxon.com/knowdesk.cfm
Vibration Analysis Distance Learning
Introduction to Vibration Analysis Course Number VS101
Next Course begins February 1, 2005!
By enrolling in this class, you will receive the following materials:
• The V-Trainer Library CD (the main class text). This CD contains over 300 pages of instruction written in simple, down-to-earth terms to make this complex subject understandable.
• The book Vibration Spectrum Analysis by Steve Goldman. This book provides a more technical text and is used mainly as a supplement to the CD.
• Online Course Resource and Research Area
• Condition Monitoring Discussion Forum
• Access to a live instructor via email or pre-scheduled group teleconference sessions.
Total course time to complete by devoting 2-3 hours per week: 8 weeks - 12 weeks
To learn more or to register please call 239-985-0317 or...
http://www.vibrationschool.com/distance_course.htm
In-rush/Start-up Analysis
When performing a start-up test using current analysis technology it is important to separate the mechanical and Electrical influence on the current signal. If an electrical problem such as a stator fault exists, it will have an influence on the instantaneous in-rush current.
Mechanical problems such as a locked rotor or load related anomaly will have no effect on the instantaneous in-rush current but may extend the start-up time. The instantaneous in-rush current is expected to be 5-7 times the full load amperage and on many designs can be 10 times FLA. The in-rush current should be identical to previous tests minus minor changes due to winding temperature.
Tip provided by PdMA
www.pdma.com
Toll Free: 1-800-476-6463
Tel: 813-621-6463
Failure #7: Insufficient testing of software
This failure is related to the previous one. Just as you check out vendors and their services, you should check out the software for the desired functionality. All too often, companies have purchased software based on what they saw during a demonstration. Then, once they have the software, they find it doesn’t do everything exactly as they thought it should.
The best method to use in avoiding this failure is the testing of the software for a period of time, typically called a pilot. Usually a week or two is sufficient. However, to be fair to vendors, it is best to have their trainers on site during testing. This precaution ensures you are using software packages correctly and not overlooking any of their capabilities. Also, expect to pay for a trainer’s time while he or she is on site.
During tests, be sure the right people test the software. It does not do much good for managers to test software if they are not going to use it every day. It is best to use the planners, supervisors, stores clerks, etc. these end users quickly will let you know how the software works amid whether or lot it helps them to do their jobs.
This issue becomes even more important, when you are purchasing customized software. The failure to check the customized package against the specified requirements has led to many problems for both the users and the vendors.
Tip provided by GenesisSolutions
Tel: (203) 431-0281
www.GenesisSolutions.com
http://www.reliabilityweb.com/forms/gene_reg.htm
Electrophysics EZ Therm High Performance Infrared Thermal Imager Features:
• High Resolution Image
• Brilliant Color Display
• Accurate Measurement
• Simple User Interface
• Lightweight – easy to hold design
• Visible Flash Camera
• Optional wireless image transfer
• A price you will not believe
Find out how much you will save on your next high performance thermal imager! Enter your guess online and Electrophysics will automatically enter you into a drawing for an iPAQ PDA (a $700 value).
http://www.electrophysics.com/eztherm/
Sometimes when analyzing a spectrum, it is difficult to differentiate between unbalance, looseness and misalignment. Their signatures all have a 1 times RPM peak and multiples of running speed peaks, excluding pure unbalance. One way to quickly decipher what is causing excessive vibration is to look at the time waveform. For instance, unbalance will display a sinusoidal pattern, whereas looseness will show random impacting.
Tip provided by LUDECA, INC.
Distributor of the new VIBXPERT data collector/vibration analyzer http://www.ludeca.com/vibxpert.htm
Tel: 305-591-8935
http://www.reliabilityweb.com/forms/ludeca3_reg.htm
Compressed Air Leaks – Start your leak inspection program by finding the big leaks first. While performing an ultrasonic leak survey in a complex system of piping smaller leaks can be masked by larger ones. Find, tag, and fix the gross leaks first. Once the gross leaks are fixed the system pressure will rise, especially in the area where the leaks were. Now return to that zone and re-scan. First confirm that the tagged leaks were indeed repaired properly. Satisfied by that, remove any leak tags from previous surveys and continue to scan the area for more leaks. Because system pressure has increased, the smaller, more difficult to find leaks will produce more ultrasonic turbulence making them easier to find. With the competing ultrasound from the repaired gross leaks are gone, a final inspection is now possible.
Tip provided by SDT North America
Toll free: 1-800-667-5325
Tel: 905-349-2020
http://www.sdtnorthamerica.com/new/what's_new.htm
Prefill piston pumps and motors to prevent "infant mortality".
When installing a piston pump or motor, always fill the case of the unit with clean hydraulic fluid prior to start-up. Failure to do so almost guarantees dry-start failure. If the unit is mounted in a vertical position and the case drain line is flexible, use this technique to fill the case:
1) Position the pump or motor horizontally (case drain port up) within reach of the case drain line.
2) Fill the unit with clean hydraulic fluid through the case drain port.
3) Connect the case drain line.
4) Mount the unit in position.
Tip provided by Brendan Casey
http://www.insidersecretstohydraulics.com/
RCA RESULTS ARE ONLY AS GOOD AS THE SUPPORT THE EFFORT RECEIVES: No matter the “brand” of RCA that you use, it is doomed without proper management support. Sure a pocket of excellence here and there may exist, but from the learning perspective for the organization, the RCA effort will not expand and strive. Most management’s feel that there commitment to RCA is done when they provide a few dollars for RCA training or software. From this point they feel that when the student leaves the training, they will be instant RCA experts who can now analyze “world hunger” type problems with absolute accuracy and in an hour. For those of us who have attended various RCA training’s, we know better. Managements must realize that in order for an RCA effort to succeed, they must:
A. Write the “fat” check to demonstrate support
B. Educate themselves in what their people are learning and approve the concepts they will implement
C. Designate a “Champion” of the effort
D. Outline their expectations with milestones stated
E. Institutionalize RCA by issuing an RCA policy and/or procedure (this will survive when the fast-track manager leaves and ensures the effort does not die with his absence)
These are a few of the “core” management responsibilities required to ensure that RCA is not only successful in the short-term, but is embedded in the culture in the long-term.
Tip provided by Robert Latino
The Reliability Center
www.reliability.com
Tel: (804) 458-0645
The Reliability & Cost Analysis Seminar in Houston March 14-18 will feature three courses: Weibull Analysis, led by Wes Fulton and Dr. Robert Abernethy, Analysis of Accelerated Test Data, led by Dr. Wayne Nelson, and Life-Cycle Costing, led by Paul Barringer.
Please call Clarion at (713) 521-5929 or...
http://www.clarion.org/weibull/weibull05/weibull05.html
In managing your workflow use your CMMS’ Work Request function as a review step prior to turning the request into a Work Order. This keeps duplicates and preplanned (as in, it will be taken care of in the upcoming shutdown) corrective maintenance from becoming part of the system. As these Work Requests are reviewed and approved they become Work Orders and move into the unscheduled planning phase until becoming part of the planned and scheduled backlog. Unapproved Work Requests should remain in the system for no longer than 2 weeks with a comment explaining why they were not approved. Then when the requestor inquires as to the status of their request and provide the Work Request number the information is readily available.
An excellent way to keep track of the Work Requests, the status of Work Orders and manage workflow is to use the scheduling function of your CMMS.
Reader Tip provided by Mike LeCompte
Maintenance Systems Development, LLC
Tel: 843-576-1433
www.maintsysdev.com
http://www.maintsysdev.com/pages/364357/index.htm
To save the threads of a stud when you need to grab hold of it. Since double nutting tends to damage the threads and doesn't always provide enough hold, and you may not have room to double nut in some cases. What I have done in the past is take a nut of the same thread size and weld it to the Jaw of vice grips, then cut the nut in half using hack saw. The gap created by cutting the nut provides plenty of holding power and will save the threads from damage.
Reader Tip provided by Christopher Dibble
Manufacturing Mechanic
Thanks Christopher - your Maintenance-Tips hat is one the way.
http://www.maintenance-tips.com/forms/submit_a_tip.htm
GenesisSolutions, a professional services company specializing in industrial asset optimization, has opened an online resource library including recent articles, maintenance white papers, recommended maintenance book list and useful web links.
You are invited to bookmark this site as a "favorite" and return often as new resources are added throughout the year.
Look for the Resource Library link from the homepage.
http://www.genesissolutions.com/genesissolutions.html
Report the good news – and the bad.
There is nothing wrong with pride in a job well done. Don’t be afraid to tell everyone in the plant just how effective your Reliability program is and how you prevented a catastrophic event using Reliability technologies. Use charts on the bulletin boards and a column in your company newsletter to show your pride. However, be certain to publish your failures as well. If you missed a gearbox failure or the loss of a bearing forced an unscheduled outage, be prepared to tell the story. Perform an assessment and publish why it was missed or why the failure occurred. Maybe your equipment does not have the dynamic range to get to that part of the data, maybe the motor was not monitored because of budget and time constraints. Maybe you could have caught it using vibration analysis, but were just doing ultrasonic readings. Whatever the cause, admit the painful truth and show what is being done – proactively- to make certain that this does not occur again, even if it is upgrading equipment or just providing additional training. It will give you far greater credibility in the long run.
Tip provided by National Reliability Systems
Jack Dischner
jdischner@nationalelectrical.com
http://www.nationalreliabilitysystems.com/
When aligning machines, it is usually impossible to achieve absolute perfection; therefore, some misalignment must be accepted, provided this remaining misalignment is small enough that it causes no harm; by definition, this window of permissible misalignment is your alignment tolerance.
When leaving misalignment on a machine, ideally you would like to leave the correction at the front feet equal to or less than the correction required at the back feet, with the corrections having the same sign (+ or). Such a result always means the alignment is getting better as you approach the coupling; you always want the centerline of rotation pointing towards the point of power transmission.
Tip provided by LUDECA, INC.
Distributor of the new Rotalign ULTRA Laser Shaft Alignment System
http://www.ludeca.com/ultra.htm
Tel: 305-591-8935
http://www.reliabilityweb.com/align_iq2/aligniq_reg.htm