April 05, 2007 Motor Testing Tip
The Importance of Motor Identification Labeling
Does your facility assign and attach a permanent ID number to the motors used in your facility?
If not, you should consider starting this practice so you can track your motor assets cradle to grave. In many facilities, a motor will be used in several different applications during its lifetime.
For example, a new motor arrives at your warehouse where a permanent identification number is attached; a quick incoming motor test is done to set a motor health baseline and then is put into the storeroom. Later it is used to replace a failed motor that is driving a condensate return pump. The motor is added to a route for periodic motor testing.
Over time, the bearings get over-greased and the subsequent contamination is seen via the change in circuit impedance causing the electrician to recommend a clean, dip, and bake of the motor. The motor is pulled, sent out for service, and returned to the warehouse. Upon return from the motor shop, it is again tested to ensure the work was performed properly and placed back into the storeroom. A month later, it is pulled and is used to drive a scrubber circulation fan.
By having a permanent identification number attached to the motor and using that number to identify the asset in the Motor Diagnostic Software, the electrician will be able to keep the entire previous motor test results collected for that motor, regardless of what application it is being used in. If the motor ever ends up requiring a rewind, new baseline data can be collected and compared to the pre-rewind data to again ensure that proper repairs were done and that the motor returned from the motor shop will perform to its nameplate expectations. This new test data is used to set a new baseline that all subsequent tests will be compared to.
The net result of this process is you will have complete historical test data for this motor that will be valuable for diagnosis of motor system faults that may occur in the future, regardless of what motor system it is installed in.
Tip provided by BJM, ALL TEST Pro
800 952-8776 or 860 395-2988
http://www.alltestpro.com
April 05, 2007 MARCON-2007 by the University of Tennessee
May 8-11, 2007
Knoxville Marriott
Knoxville Tennessee
3 Pre-Conference Workshops:
* Reliability Engineering Principles by Paul Barringer, Barringer & Associates, Inc.
* Human Error Reduction – Robert Latino, Reliability Center, Inc.
* Creating Value through Maintenance and Reliability: Proven Methods to Deliver Bottom Line Results by Paul Casto, Eastman Chemical and Dr. Rupy Sawhney, UT College of Engineering
34 Reliability Improvement case studies from organizations like Northrop Grumman, Sandia National Laboratory, Alcoa, Duke Energy, Michelin, Eastman Chemical, US Army, The National Gas Co. of Trinidad and Tobago and Agrium.
MARCON-2007 offers extraordinary learning and professional networking in a relaxed setting in downtown Knoxville.
To register please call 865-974-9625 or…
April 05, 2007 Even More Feedback From Recent Filter Tips
We have a hydraulic power unit that has 4 “kidney” cooling/filtration loops.
The filters specified are 3 micron, with a 25 psig bypass in the filter head. A pressure switch gives a dirty filter reading and warning at 20 psig. At some point, a vendor substituted an apparently equivalent filter element from a different manufacturer.
After the substitution, we began getting dirty filter warnings on a frequent basis. Investigation showed the differential pressure across the substitute filter was much higher then the original - the pressure drop on a NEW substitute filter was 15 psid - meaning even cold oil had the potential to cause the dirty filter alarm.
Reverting to the original filter solved the problem. The lesson to learn is that, despite claims, not all equivalent filters are truly equivalent.
Ed Allen
Assistant Manager
6 Flags
April 05, 2007 RELIABILITY Magazine 12th Year
It’s A Celebration!
In appreciation of the outstanding efforts of the Reliability community and their support for RELIABILITY Magazine over the past 12 years - YOU are invited to subscribe for one year at a special rate of just $25. That is a 75% savings!
April 05, 2007 Root Cause Analysis (RCA) Tip
Avoiding a disconnected RCA analysis tip:
When conducting Root Cause Analysis (RCA) investigators can get caught up in the apparent causes of the failure.
This can come in the form of interviews that contain repeating comments about the reason something failed that make logical sense.
When you hear these kinds of comments realize it may be conventional wisdom you are hearing. You must treat the interview as information that may provide some insight to possible hypotheses for your analysis. Hypotheses have to be verified as to whether or not they occurred. If you base your entire analysis on conventional wisdom you are in the box before you even begin your analysis.
This can lead to a incomplete analysis because other possibilities are not considered.
Tip provided by Mark Latino
Reliability Center Inc.
http://www.reliability.com
April 05, 2007 Alignment Tip
What non-repeatability may be telling you.
Regardless of what type of alignment system or method you use, corrections should never be attempted if the readings don’t repeat within an allowable tolerance. Here are some things to check for when this happens;
a) Make sure all components and bracketing are secure to the shaft, that nothing is rubbing, and that all equipment hold-down bolts are tight.
b) If possible, increase the measuring average of the laser to compensate for ambient vibration. Dial indicator users cannot compensate for this effect.
c) Tooling used to turn large machinery may be deflecting the shaft and influencing readings; use the Multipoint method of taking readings if your laser system offers this.
d) Wait for recently run machines to cool off to ambient temperature and all thermal gradients within the machines to stabilize before taking readings.
e) After eliminating all of the above, you may very well still have machinery issues such as bad or excessively worn bearings.
Tip provided by LUDECA, INC.
ALIGNMENT * VIBRATION * BALANCING
http://www.ludeca.com
Tel: 305-591-8935
April 05, 2007 Use Business Intelligence to Improve Equipment Reliability
Use your EAM/CMMS system to record equipment failures and capture which components were involved and what conditions caused the failure. Once you have started recording this data you can then use Business Intelligence applications to perform a Pareto Analysis that lists the equipment in the most often failing to least often failing sequence and also perform a Pareto Analysis on the cost of the failures to see the most costly to least costly failures. You can then work on the costliest or most prevalent failures first to focus your efforts where they payoff.
To learn more please call (864) 458-3333 or…
April 05, 2007 Bearing Lubrication Tip
Check those rebuilt motor bearings ! ! !
A couple years ago we noticed that we had a couple premature motor failures after bearing rebuilds. As a result we started checking the rebuilt motors as they arrive from the shop.
We found that on a few the bearing housings were not thoroughly cleaned at the shop. A small stainless rod ( tig welding rod ) is used to probe down the grease tube to the bearing and slowly removed. The grease / debris is wiped on a white grease rag. If there is visible contamination in the grease tube area (usually burnt grease) then it may be throughout the bearing or it will be pushed into the bearing the first time that the motor is lubed after it is put in service.
After seeing our results the rebuild shop added some procedures for their techs to ensure that the housings are cleaned and that new lube tubes are installed.
Tip provided by Jerry E. Baker
PdM Lubrication,BIO-PDO
Tate & Lyle, Loudon TN Plant
Thanks again Jerry! Your Maintenance Tips hat is on the way!
