SMRP Chicago Chapter October 15 2009 Meeting

October 15, 2009, SMRP Chicago Chapter Meeting.

SMRPMeet.pdf

From the MotorDoc: Something Lite (Reflection)

Once in a while I like to consider something philosophical. Following is a piece I wrote to break through writer’s block a few weeks ago while working on a project for my writers’ group. Yes, it does even happen to me.

REFLECTION

Howard W Penrose, Ph.D., CMRP

I sit, trying to think what to write as I gaze across the pond outside my window. The two fountains at either end spray high into the air in the sunlight with only occasional clouds obscuring the rainbow that fades in and out from the nearest one. The colors deepen and lighten then fade out completely, then come back again.

The ripples move out from each fountain in a circle, rebound against the irregular edges of the pond, then back in again. The chaos collides with the chaos from the second fountain such that a regular pattern forms on top of the pond. Every once in a while a breeze comes up changing the pattern, causing the wavelets to shimmer and dance.

Reflections of the surrounding homes dance within the pattern. Shapes without solid edges until you look up slightly. A flock of birds fly from roof to roof in regular intervals, land on another roof, take off again and swoop over the pond and onto another roof. It is almost clockwork. They find shade, huddle under an overhang, then start their dance all over again.

The branches of the evergreens around the pond sway in the breeze. It is cool, but not too cool, fall-like weather in August. The pinecones dance as if they are bells. I hear the tinkle of a wind chime and the bark of a small dog.

The birds swoop by my window. I am starting to recognize the lead bird, it seems to be the same one, waiting for his troops to land, then ordering them all up and off again. Their flight is reflected as a new pattern of light upon the ripples in the pond. This time, one stays behind and, now, flies to a different rooftop. Will the others follow?

I gaze back down towards the pond. All of those peaks and valleys colliding with each other, driven, yet responding if only to cancel each other out or change direction, even slightly. As if they reflect personal interactions. Lives begun, changed, extinguished, outside forces reflecting upon them and others as they change direction.

As we pass through life, we are reflections of our experiences. We are ripples, rainbows, wind and blurred mirrors of our surroundings. We travel and change each other in different ways, affecting those around us and others in turn. Sometimes we add, sometimes take away, sometimes cancel. We each live our peaks and valleys as we progress, sometimes we shine and sparkle, sometimes we fade.

But we are all reflections of each other.


I hope you enjoyed. Lots of information in this newsletter so keep on reading!

Sincerely,
Howard W Penrose, Ph.D., CMRP

Find me on Twitter (http://twitter.com/motordoc and http://twitter.com/IEEE_DEIS), Facebook.com and LinkedIn.com

A Review of Motor Management

A variety of concepts related to the term ‘motor management’ have been presented within industry since the 1990’s. Many of these programs are actually ‘energy-efficient electric motor retrofit or repair/replace’ ideas that actually only make up a small portion of the overall industrial opportunities when properly managing electric motor systems. Normally, such things as preventive and condition-based maintenance and other motor-system opportunities are left out of the program with a very narrow view of the overall system. While it is important to view energy and environment when making electric motor decisions, it is more important to focus on the reliability, life-cycle and business-related considerations for overall corporate success.

Presently, over 20% of the USA Gross Domestic Product (GDP) is invested in maintenance programs with over half of that amount due to improper maintenance. An additional $2.5 Trillion in business opportunity was lost as a direct impact of poor maintenance practices. A majority of the systems affected are part of plant electric motor systems.

For more information, see the article “The Concept of Motor-System Maintenance and Management,” and related motor management articles in our articles archive: http://www.motordiagnostics.com.

What Infrared Can Tell You About Your Electric Motor

Infrared can be used to thermally evaluate equipment. However, it requires direct contact of objects and line of sight for the system to work. In many electric motors, there are ribs between the frame and stator core which acts as an air thermal insulator. The result is that the surface temperature of the motor may be radically different than the actual winding temperature. At the same time, bearing inner and outer races are in direct contact with the bearing housings and shaft providing more accurate temperatures for evaluation and trending.

So far as the overall temperatures of the electric motor, there are a few temperatures that make up an electric motor’s operating temperature:

- Ambient Temperature: environmental temperature immediately around the motor. This limit, often 40C, is a limit for heat transfer from the motor.

- Temperature Rise: generated by the losses of the motor during operation and is directly related to the load of the motor. Basically, if the load rises, the temperature increases.

- Total Temperature/Operating Temperature: the combination of the ambient temperature and rise. As described, this value will vary with load.

The temperature limits for an electric motor are based upon the insulation class of the motor and bearing grease limits for the associated components. For instance:

- Class A = 105C – based upon the original oil and paper or tar and paper insulation systems

- Class B = 130C – commonly found in older standard efficient electric motors

- Class F = 155C – commonly found in energy and premium efficient electric motors

- Class H = 180C – often relates to insulation systems for high temp applications or motor repair

- Class N = 200C – high temperature applications

For motors that have service factors of 1.0, the allowable total temperature is the insulation class temperature minus 10C. For motors that have service factors of 1.15, or better, the allowable total temperature is the insulation class temperature. For example, if a motor has a Class F insulation system, a 1.0 service factor has a temperature limit of 145C and a 1.15 service factor has a temperature limit of 155C.

The temperature limits are not reflected on the surface/skin of the electric motor, as some believe, because of air gaps and the design of an electric motor to eliminate the heat generated by the losses of the motor. Different designs will generate different levels of losses and heat dissipation. The temperature limits, instead, related directly to the winding temperature of the motor. This requires either a direct line of sight of the motor windings or the motor core.

Thermal imaging has been used to identify specific point losses on an electric motor, with limited results. For instance, you have to know the loading of the motor at the time of test. Plus, in the case of totally enclosed fan cooled, or totally enclosed blower cooled, the skin temperature of the motor will vary from the fan end towards the drive end of the motor. This does allow the thermographer to identify cooling issues in these types of motors (ie: damaged fan or plugged cooling).

So, what can infrared tell us about our electric motors?

- For motors of constant load they can be used to identify ‘differences.’ However, significant temperature increases identify systems that have already failed;

- Bearing temperature by looking at the shaft and housing temperatures;

- Cooling issues;

- Severe faults;

- Can be used to determine where thermal issues are from.

In many cases, the use of just infrared technology can take significant time to evaluate or identify what is wrong and will often not provide enough detail to show how out of tolerance something is. For instance, thermal imaging may identify misalignment. However, what is good or bad? How out of tolerance is the alignment? For that you would have to perform an alignment check. Meaning – the right tool for the right job.

Does this make thermal imaging the wrong tool? No. It may be used as a system of scanning groups of equipment in order to identify gross defects which may be addressed through the application of the proper technology or inspection.

Consideration for Electrical Signature Analysis in Variable Frequency Drives

For some reason, variable frequency drive driven equipment seems to carry a mystique for analysis. In truth, it just requires the user of diagnostic technologies the ability to expand the way they think when they look at data. Fault signatures and peaks are just the same as a standard motor, with the following exceptions:

- Currents should be balanced within 7% because voltage must be balanced on the output of the drive. If there are voltage related unbalances, then the drive should be evaluated, if a current unbalance exists without a voltage unbalance, then the motor and connections should be evaluated. It should be noted that the allowable current unbalance is meant for certain winding designs that are common in ‘smaller’ (less than 250hp) motors that have ‘concentric’ windings versus larger machines that have ‘lap’ windings.

- Expect very high harmonic content because of the type of voltage and current waveforms that exist. In most cases, this requires the application of filters or shaft brushes to avoid shaft currents.

- The line frequency and speeds will vary from test to test or during the same test. Evaluating and confirming the line frequency and operating speed, either through the signature or separate readings, is important as virtually all faults are related to one or the other. It is also important for when performing trending readings.

- You have to look past the electrical ‘noise’ that will exist in higher frequency data analysis to identify the issues in the system. This means knowing the fault signatures that you are looking for or practiced pattern analysis (covered in Electrical Motor Diagnostics: 2nd Edition).

There are other considerations that we will cover in future newsletters.

On Change Management

One of my favorite subjects is change management. There is just something about it that can be considered both a powerful tool and a terrific weapon against competition. In either case, it must be remembered that both weapons and tools can be turned on the wielder, should either be misapplied.

Change invokes fear in many people, even when it is to their benefit or does not affect them at all. Unfortunately, many see the fact that there is fear, protectionism, or negative reaction as a positive response that change is occurring. This is a bad indicator for progress or positive change.

The use of change as a tool requires the architect of that change to have specific goals or series of goals in mind with each change being an effective step towards those goals. The application of change without goals or proper planning is simply chaos that cannot be managed in a process type environment. The result can be a reduction in quality, timeliness, and lost opportunities such as missing issues within a system. Solid processes in production or service in industry, manufacturing and personal environments allow for specific measurements, such as key performance indicators, and a methodology to identify areas for improvement. Once thought of as a way to 'keep people on their toes,' chaotic environments do not allow for proper measurement systems and generate environments of high stress.

So, how do you identify and manage change in a positive manner?

Often the 'change agent,' or manager/consultant brought in to make the change finds a potentially overwhelming situation. There may be a lack of documented processes, the documentation does not meet the processes, or the whole system may be in complete chaos. There are choices that must be made: where to start? How much to take on? Sudden and abrupt change? Or, slow and steady?

Based upon the agent's experience, there may be some quick changes that can be made to improve the situation and make it manageable. The next step is to gather information and records as well as observing the processes and business environment. While doing this, the agent must also determine the goals of the organization, not just by what is written, but by the actions of the leadership – actions speak louder than words, written or spoken.

Once that direction is determined and the agent has the 'lay of the land,' then the real work begins. First, determine what goals are going to be set in near, mid and long-term (immediate, months and years). Next, what measures can be used to determine if the goals are being met and the associated gap? Before getting down to the real changes, gage the acceptance of the company to change by implementing a relatively minor change in policy or process that impacts a large segment of the organization. This assists in determining: 1) where resistance will come from in the larger picture; 2) who will be of value during the change process; 3) will leadership support the programs? All of which will help determine the time-line and if a change management program is feasible in the company.

Do not take on everything at once! Select a specific program or project and maintain a steady pressure on it until it begins to operate on its own. Basically, prepare the next project once the first one is self-sustaining. Otherwise, the implemented changes will slip backwards.

Beware the idea of coming in, as a change agent, and laying about with unplanned or reductionist changes to the system, as is a common practice when trying to show immediate progress. You must also communicate the changes, support the personnel implementing the changes, help some workers through the challenges of dealing with change, and deal fairly, but aggressively, with those who deliberately attempt to prevent the change, especially those who undermine the effort in order to support hidden agenda that are contrary to the goals of the company.

Personally, I have never understood the motivation for that last statement, but have seen it often enough to be concerned. Why would personnel (leadership or otherwise) want to harm the company or organization that supports them? But it happens, and those persons should be eliminated from an organization quickly! They tend to be an insidious poison that eats away profits and effort through personal politics or undermining efforts through rumors and counter-productive activities.

When we go back and review those programs that have been successful within industry, and those companies that are highly profitable and in demand, a common thread exists: they each have solid, but flexible, processes that support their programs. For instance, you may have heard of the 'Toyota Way,' and the time when Japan was dominating over USA quality and cost. Those successful programs were not implemented in an environment of chaos. They were implemented during times of tightly controlled and measured processes and attention to detail. The same goes for companies like Nucor Steel and others who not only took charge of their processes but also identified the importance of the most flexible systems: people.

In this there is a fine line. You need to support the people who implement and move within the processes and changes that need to be made. At the same time, you need to tightly control the processes, set goals and policies, and determine the measurements those personnel must work within. Lean too far with flexibility without constraints in one direction and you have chaos. Too far the other direction, you have autocracy with the organization paralyzed during times when decisions must be made.

What are the rewards? A company that has clear processes and flexibility, or culture of change, can adjust to virtually any business climate. They can also prevent the competition from latching on to any specific issue, providing a solid defense in the marketplace, while showing a tremendous offense by being able to respond to customers easily while the customer knows exactly what to expect. With solid measurements and consistent processes, quality and time issues can be quickly identified and addressed.

Seeing as business is civilized warfare (ok, sometimes civilized) the concept can be re-enforced by looking at such conditions. If you have a force of structured, disciplined, process driven, fighters, such as the Romans at the height of the Roman Empire, against an angry mob, who is going to win? The group that knows exactly what to expect of themselves? Or, the chaotic mess?

Know yourself and win 50% of engagements, know your enemy and win 50%, know yourself and your enemy and win virtually every battle.

As process and change begin to occur towards the goals that you have set for your organization, it is important to keep a constant level of energy aimed at the systems put in place. If a system is changed and then abandoned, as with all systems of order, they will tend back towards chaos. Basically, any orderly system is subject to entropy. To properly maintain your system, buy-in is important across all levels within the organization.

So, as we come upon a new age of prosperity, which are you? Does your organization act as an angry mob? Or are you organized, disciplined, and flexible?

The future is here. Are you ready?