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11/4/2016 1 Comment How smart can a dumb motor get? I have a friend in the industry who gets upset when someone tells him “My AC motor quit running right”. His response is always something like, “It’s not the motor. The motor is dumb. If you apply the proper power and if there’s no issues on the load side, it’s gonna do what it’s supposed to do or not run at all”. Which is essentially true. Sorry motors, but your just not all that smart. Except maybe DC and servo motors. Even with those though, the brains are mostly in the drive controls.
Could an AC motor be made smart? You could argue that by applying a VF drive it’s now smart. It will speed up and slow down on demand. But those are normally mounted several feet away or even in the next room so not an integral part of the motor. Not that it couldn’t be mounted in an oversized junction box but why do that? Drives are typically electronic devices and prefer a nice comfy control room environment away from the heat, vibration and contamination that those dumb old workhorse motors live in. It could be done though. Who knows, maybe someone is already doing it. Okay, so our motor can speed up and slow down by itself, now let’s imagine it’s smarter yet. It senses incoming current and controls start up torque very slowly to avoid stressing its copper muscles and insulation ligaments. No mechanical stresses from the winding flexing in this smart guy. And once up to full output, current and voltage are sensed and kept in near perfect balance through an integral variac or some other new technology. This is all already doable and being done in a few cases but external to the motor with surge suppressors, chokes, variacs, soft starts, etc. Now let’s look at the smart mechanical features. Ultrasonic sensors could tell the motors brain its bearings are needing a fresh squeeze of lube and it’s automatically added. In fact, let’s get smarter yet and measure the bearings operating temperature and have it add an appropriate rated compatible grease for the current operating conditions. The ultrasonic sensors would also detect when just the right amount of grease has been added. Of course, our smart motor also protects itself from outside contamination with mechanical seals on both ends. Stray shaft currents are mitigated with insulated ceramic coated bearing housings and integral grounding devices. And the cooling system is thermostatically controlled with high speed fans and high surface area fins to quickly dissipate the heat and keep the temperature just right regardless of the motors operating speed. This will also improve efficiency by eliminating the drag caused by the cooling fans rotation when it’s not needed to run continuously. Yeah that’s all well and good you say but what if the motor wasn’t installed properly and there a misalignment issue? That’s where the integral “SmartBase” comes into the picture. With pressure sensors on the bearings the motor automatically adjusts itself with a series of tiny electric jack screws to maintain perfect alignment and load balance on the shaft. But let’s not forget external communication and the industrial internet of things. If the smart motor needs a human to intervene when it’s systems fail or aren’t enough to self-correct it calls or texts you and asks for your help. Not just a generic call for help but something like, “I’m sensing pressure on the right side of my drive end bearing and can’t seem to correct it. I’ve run my diagnostics and it seems the drive side horizontal jack screw is non-responsive”. Or maybe the request for human intervention is just for a simple task like replacing a lube cylinder. Then the call might go something like, “I’ve just dispensed the last of my high temperature grease. Please replace in the next 10 days before my next lube cycle”. Maybe despite all of the smart features in this motor it still needs an occasional recondition. It could alert you to this fact and send notifications to production and the plant manager predicting when the bearings will fail and start damaging the motor if not shut down and removed. It could even notify the repair shop what parts will be needed and when the motor will be available to be sent in. Although some of this is probably impractical, as the cost of sensors comes down and new products are brought to market who knows how smart our dumb friend will become.
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 Condition based monitoring of your plants assets can get pricey. American MTS has many of the devices needed for this currently in our toolbox including vibration analyzers, a laser alignment kit, ultra-sonic test equipment, infrared cameras and a variety of electrical test equipment. We have invested more than $250,000 in these tools so our customers won’t have to. This large upfront investment in equipment and training to learn how to use and understand the data collected from them makes setting up a condition based monitoring program cost prohibitive for smaller companies. Are there other options with a lower price point and learning curve for the do-it- yourselfers? We were asking ourselves the same question. This led us to research different options currently available. After looking at several lower cost options we decided to become distributors for the one that we believe gives the best bang for the buck. ITT has developed a device called the i-ALERT2 that is smaller than the palm of your hand, will continuously monitor vibration and temperature while costing much less than traditional options. In fact, for less than $500 you can monitor your asset from your smart phone or tablet. Let’s take a closer look at this powerful little tool.  As you can see from the above picture the i-ALERT2 has a very small profile that makes it easily installed in tight places or on smaller applications. In addition to its small profile, the device is also water resistant, has a battery life of 3-5 years depending on usage and communicates to your smartphone or tablet with a free app. Like Yoda from Star Wars, you can’t judge the i-ALERT2 by its size.  The i-ALERT2 can be installed in several configurations including epoxy, magnet, or hard mount with a tapped hole. Vibration is measured in three planes: horizontal, vertical and axial. Whenever possible, the light should be in-line with the shaft to ensure these coincide with the app. Once you have decided which method of installation is right for you and it is set in place; simply remove the sticker from the device and it will begin working its monitoring magic. Once the sticker is removed it powers up and begins taking readings. The device will track vibration and after 25 hours of run time will automatically set its own alarm parameters 25% above average recorded values. You can also alter these parameters within the app if you are experiencing frequent unwarranted alarms or want even tighter monitoring bands. After confirmation of change the app will communicate with the i-ALERT2 to set the new limits. You’re now locked and loaded.  The lights on the i-ALERT2 provide a quick reference guide. The device will flash three different colors LEDs. While everything is running well and inside acceptable parameters it will flash green. If a measurement is above the alarm set points the light will flash red and the time and date of this occurrence is recorded. While the app is communicating with the i-ALERT2 the light will flash blue. Now that everything is set and running, what’s next? Well, that’s really up to you. You can use the device by watching the lights to know when there is an issue. You can create a periodic route to download the information from your i-ALERT2 for trending data over time. If alarm conditions are occurring, you can compare the FFT graphs to readily available sample charts or send the data to American MTS and we will analyze and report back our findings to help you determine what steps are needed to correct the issue. The device automatically checks for alarms every five minutes and records FFT vibration and temperature data once per hour.  As you can see this simple device can make a world of difference in allowing you to keep a close eye on your assets health. If used properly the i-ALERT2 can help you catch a failure long before it becomes catastrophic greatly reducing the repair cost and eliminating unplanned downtime. At American MTS we are constantly striving to help our customers reduce stress and rest easier. We believe that this powerful device is worth considering to help you feel more at ease when you kick off your boots at the end of the day.
  Larger, more sophisticated manufacturing companies have been enjoying the benefits of condition based maintenance practices for many years. Unfortunately, the cost of purchasing analytic equipment, training and implementing these programs have prevented many small and mid sized companies from gaining traction in this cost saving methodology. New technologies on the market today are changing this dynamic creating opportunities for all maintenance departments, large and small, to reap the rewards of a more proactive strategy. Before exploring some of these new products lets first define some terms that are used by reliability professionals, sometimes with great debate as to their differences. For this discussion, we will assume the following: Preventative Maintenance (PM) – the practice of taking proactive steps to prevent asset failures and unplanned downtime. These could be time based or condition based in nature but the end goal remains the same. Predictive Maintenance (PdM) – an element of preventative maintenance that uses historical performance or operating condition data to predict when an asset will reach functional failure. Condition Based Maintenance (CBM) – the practice of periodic or continuous monitoring of an asset's health through temperature, vibration, sound waves, power usage and other methods to help make decisions on when to perform repairs or maintenance. Simple time based PM is a common practice that consists of adding lubrication, cleaning, checking tightness, etc. Most companies employ at least some form of this even if it’s not consistently carried out. The problem with time based PM, in addition to getting skipped if there are other “fires” to put out, is that you may be lubricating an item that doesn’t need it wasting time and lubricant. In the case of certain equipment such as an electric motor you may end up hastening its failure rather than preventing it.  This is where condition monitoring comes in. You might say, “We monitor the condition of assets, when the bearing starts squealing we tell production we need to shut the machine down and fix it.” Okay, technically that fits the definition. But production may say that you can’t take it down for two weeks – or more. Two days later, in the middle of the night, you get that dreaded call. The machine is down; it’s costing $2000 every hour, customer orders are now behind and it’s your fault. Sound familiar? This is where asset heath condition monitoring can provide a different outcome. That squealing bearing was giving clues many weeks or even months prior. Using devices that can pick up these clues gives you more time to plan. Up until recently the only way to do this type of condition monitoring was to spend $30,000 - $40,000 or more on equipment, $5000+ on training and then prioritize what needs to be monitored. Then hope that cutbacks or the person who received the training leaving for greener pastures doesn’t sidetrack your efforts. Far too many companies have equipment sitting on a shelf somewhere that no one knows how to use or exactly what it does. There are other ramifications of not doing condition based monitoring that make the investment given in the previous example a bargain. It’s possible that the machine failing could present a health risk. There’s the cost of downtime from production lost and idle employees. Oh, and if that bearing is squealing chances are good there will be expensive damage to it's housing or shaft. But still, convincing management of this can be challenging. Today there are new options with a smaller upfront investment. An entire industry of outside companies has cropped up that will come in and provide maintenance and reliability services. These companies will consult with you to develop an in-house program or provide a turn key solution where they do the monitoring and simply make you aware of troubling equipment trends. Even still, there will be a cost involved in setting up the program as well as the ongoing monitoring. Getting management to understand that this cost is an investment and not an expense can be difficult especially when cash is tight even though it will improve the company’s financial position in the long term.  There is also a new group of products coming to market now that provide a low-cost point of entry and are very simple to operate. One of these is the i-ALERT2 from ITT. They mount on a pump, motor or other moving piece of equipment and continuously monitor the equipment health. There is a simple interface via Bluetooth to a smartphone or tablet application that allows you to create routes, collect data or simply set alarms that warn you very early that things are moving towards failure. Bearing companies and motor manufacturers are coming out with similar products. In many cases these solutions can be implemented for under $500 per monitored point.
For more critical applications or for those companies that can not or do not want to monitor things themselves, cellular or internet connected devices can provide off site monitoring and alarming capability. There are forward thinking companies developing algorithms that predict when an asset will fail from the collected data. The information gathered can then be combined with data from similar applications worldwide to improve the accuracy of the predictions. This sophisticated form of predictive maintenance will maximize asset operating life while reducing unnecessary repairs. To remain competitive in a global economy, companies must find new creative ways to maximize productivity and efficiency in operations. Eliminating unplanned downtime and reducing repair costs is a great place to start. Condition based preventative maintenance along with predictive strategies provides the tools to help make this happen.  If you were asked what asset absolutely could not stop running in your facility could you identify it? Right now, you are probably thinking through the equipment you have or maybe you already know. You just performed a basic criticality assessment. One of the most fundamental and important tasks you can do for your company is to identify which assets cannot unexpectedly shut down.
Unplanned downtime is the worst-case scenario for any manufacturing company. Lost production effects everyone in the company from scheduling to billing. Mitigating or eliminating unplanned downtime should be the goal of every maintenance technician. Knowing which assets must stay running based on the impact they have on plant production is the first step towards making your life easier. This critically assessment will help you determine which assets in your facility need to be monitored and what frequency of monitoring is appropriate. You will likely decide that some assets should have no monitoring and are best left to run to failure. The question asked at the beginning either made your minds gears turn or your thoughts went directly to the asset that must run. How did you make that call? What factors did you use to determine that asset was most important? There are many other factors besides production that play a role in determining the criticality of monitoring assets. Here is a quick summary of some factors that need to be considered. Are there health and/or safety concerns? Some assets can cause significant health, environmental, and safety issues if they fail. If your assets failure will cause any of these to become an issue then it needs to ascend the list of what is most important. While production loss can be very financially painful to the company an environmental or safety hazard can be much worse. No one wants to have an injured coworker or environmental damage occur during an unexpected asset failure. Will it cause lost production? One of the most stressful times for the maintenance staff is when a production line goes down. Because these outages can quickly cost thousands of dollars, every minute of lost production is cause for concern and in the maintenance world with the production/plant manager breathing down your neck those minutes seem like hours. In determining criticality of each asset, you need to consider how many people will be idled and how large an impact will it have on production if this asset is unavailable. This should be a heavily weighed factor when deciding where an asset falls on your criticality ranking. Is a batch of product likely to be ruined? In some plants, an extended outage can ruin thousands of dollars of product. For assets that have this vulnerability the cost of a ruined batch needs to be considered and appropriate redundant systems considered. Where this is too costly or not feasible, spare parts should be stocked and a high criticality ranking for monitoring should be considered. How vulnerable is the asset? An asset under optimal running conditions will run for quite a long time. Reality tells a different story. Often the conditions the asset operates at are less than optimal which shortens the mean time to failure. Understanding and identifying these assets is important to knowing how critical monitoring will be. Are spares readily available? It always seems like the most important assets are the hardest to quickly repair. No one wants to go to management and tell them that a critical asset has failed and a needed part replacement is days, weeks, or even months out. This can lead to expensive expediting costs and overtime patch work repairs to get back running. Maintaining adequate spares is important but this is not always feasible especially if the spare is very expensive. If the spare is inexpensive it should be kept on the shelf if possible. If spares are readily available and easy to change out then this asset will have a lower rating but if the spare is cost prohibitive, then the monitoring criticality rating will need to be higher. These factors all play into the criticality assessment of your plants assets. The more historical operating information you can gather as well as equipment manufacturers recommendations the easier completing this assessment will be. This is the first step in helping decide upon a course of action for condition based monitoring, preventative maintenance and predictive analysis. It’s also the starting point for raising the bar on the reliability of your equipment keeping your plant profitably running letting you sleep better at night. |
ArchivesCategoriesAuthorMichael Huber is President of American MTS an EASA accredited service company located in the Carolina's. |
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