Vibration Analysis / Ultrasound / Remote Monitoring / Infrared Thermography

PdM pitfalls and how to avoid them

Win major payoffs from PdM with a strategic, step-by-step approach.

By Bob Koehler

As an electrician for more than 30 years, I was intrigued when our reliability crew started to implement condition monitoring processes with a support system that valued contributions from technicians.

A new, predictive maintenance culture emerged before our eyes. Electricians used to change a smoking motor in an emergency situation. Now, motors were being changed as part of a planned work schedule with the right parts at hand. There was no production downtime rush.

I’ve seen the implementation of new technologies and training to understand these new tools’ potential, as well as greater interaction among management, engineering personnel, and craftspeople who are respected and valued – unheard of for an old electrician who has seen every “flavor of the day” management program.

There have been some who have resisted, but these individuals tend to soon find a way out and leave the work to those who appreciate a tough job that offers freedom and rewards. This is, after all, the maintenance method of the future.

Out of this new culture has grown a desire for constant improvement. The dividends are obvious to anyone who knows popular maintenance culture.

One of the great things about our facility’s transition to a PdM approach is that I was given opportunities for self-evaluation and testing in accredited technology and professional fields. I am a certified maintenance reliability technician (CMRT), and all eight of our reliability group members passed the CMRT test from Society of Maintenance and Reliability Professionals. It validated the level of the program’s operation. World-class benchmark practices – and the sharing of these both internally and with visiting business units – became expected.

Culture change is one of the most difficult things to implement. I had a discussion with a couple of our old-hand mechanics about the importance of the change from area-specific maintenance, where one technician owns one area and knows the failure modes to maintain reliability, to condition-monitoring maintenance. The ability to have techs come in and do a sweep of machinery health with new tools is the new world. To be competitive, you can’t afford to have one technician, no matter how dedicated he or she is, be confined to one area.

I asked the technicians what happens when the area maintenance person is off or when he or she transfers. Where’s the dedicated maintenance provider then? The logic is undeniable, but it’s a hard pill to swallow for a proud maintenance craftsman. Giving that same experienced technician condition monitoring tools will multiply his or her effectiveness.

Making these arguments will ease the pain of change, but it takes coaching from someone who understands the trenches to make a new approach and a new mentality stick. Reinforcing the program’s worth helps technicians focus on improving overall machinery health rather than obsessing over repairing one piece of failing equipment immediately. Craftspeople, especially old-school dedicated craftspeople, love to fix things. To limit that experience to one failure found leaves the 10 other failures that haven’t been found out yet.

Sharing success stories and experiences should be a tool for implementing PdM in other company locations. Besides helping avoid problems that have already been experienced in starting a PdM program, it gives hope to the techs who are encountering difficulties in changing culture and applying new condition-monitoring tools. To know that there are others who are experienced and who have been through similar circumstances and are willing to share and listen takes away from the isolation that maintenance technicians often perceive.

Keep in mind...

As you progress along your PdM journey, keep the following truths and best practices in mind.

A tech who has no training won’t know what is and isn’t important when gathering data. Guidance in data gathering and analysis is essential. I learned so much when I started, but I had an experienced motor tech to mentor me. Confidence is built on success.

Training in aspects of whatever test equipment is being used for condition monitoring is a necessity. Providing accurate and incisive analysis and reports will give a technician credibility. There must be a basis for craftsmen and planners to act with surety on technicians’ recommendations.
Get rid of the “How long until we fail?” mentality. Once an anomaly has been discovered above a set point for failure mode, planning to remove the equipment should start. Removing the equipment with optimum time for work that doesn’t interfere with production uptime and having jobs completely kitted and ready for the area maintenance craftsmen are vital to successful predictive maintenance.

Costs of replacement equipment should be calculated with savings of lower repair costs and downtime reduction from unplanned equipment maintenance.

An autopsy of equipment in failure mode reinforces the value of early removal. Findings should be documented with photographic evidence and by saving damaged parts. There should be a consistent methodology to autopsy. When there is a focus on expected points of failure, an unexpected piece of evidence could go unnoticed. Documented conditions may be re-examined for root cause of prior autopsy if all points are included for analysis.

Reporting PdM work done and PdM program successes in a newsletter or other format can be very helpful. In our case, sharing autopsy findings and IR pictures of before-and-after conditions was a powerful way to bring to light the possibilities of PdM condition monitoring. A picture is worth a thousand words. In addition, the people who are writing the checks need to see reward for their investments.

The problem with a successful PdM program is that asset owners and managers are looking at the bottom line and not always how you arrived there. It can be enticing to cut an equipment repair or an improvement when it seems that things are running smoothly and emergency work has been minimized. This desire for short-term savings, however, can result in a return of the costs that were being avoided by the PdM program.

Wide-ranging gains from PdM

Our facility saw numerous gains from the shift to a predictive maintenance approach. These came in part from training craftspeople to use PdM tools.

Here are three examples of how training craftspeople on the tools for and the value of predictive maintenance yielded  strong dividends.

Example 1: A DC crane hoist problem was making it necessary to have mechanical maintenance personnel perform several adjustments over a short period of time. The task to get the twin-series hoist brakes to open at the same time was causing downtime and production loss.
Although they seemed to be functioning well, one of the coils was losing portions of the internal coil loops, resulting in magnetic power losses. This was found only when the electrical reliability team was called in to consult on the problem. The standard VOM could not detect the variance in induction or micro-ohm readings.

After training, area craftspersons were able to detect inductance losses in brake coils during standard PMs using PdM tools. PdM technicians trained the crane crew to use the test instruments and understand the results. Results get recorded and trended for planned replacements when anomalies are found. Incorporating PdM into a PM program reduced unplanned downtime and hoist damage.

Example 2: During IR inspection routes for the power conversion system in a smelter rectifier station, PdM techs were finding failed diodes in large rectifier arrays via simple switch-inspection sweeps.

A low-cost IR camera was purchased, and PdM techs trained area electricians on IR inspection techniques. Area craftspersons then were able to check their equipment for peak performance and reliability. As a bonus, this also reduced the number of IR inspection routes for the PdM technicians.

Example 3: The electrical reliability group was asked to provide a single-point training session for area electrical maintenance groups. Several autopsy examples were displayed, and a standard kit for sealing, including directions and components for sealing all types of motors, was presented. The training gave the electrical craftsmen a view of what was to be done and how it affects motors’ life and reliability.

The training was well-received by most craftsmen and led to a standardization of motor sealing techniques in all departments. Central maintenance areas were stocked with sealing kits for use by electricians when needed. A plan was put in place for additional training, too, for new area electricians and new supervisors as well as a refresher for experienced craftspeople.

PdM’s value to American industry

The state of maintenance in American industry is still too largely reactive. Putting emergency work on problems that have already occurred and staying with PMs that haven’t proved to be effective for the sake of completing schedules are the hallmarks of a failed maintenance system.

The shape of the future is going to be maintenance technicians using precision condition monitoring equipment to focus maintenance work where it will be planned and scheduled. The reward for the new PdM workplace will be cost-effectiveness and safety. Reliable equipment arriving to maintenance centers for planned work outages creates an environment of safety and ensures that craftspeople can best focus on the job at hand.

New tools let craftspeople and techs understand that the health of their equipment correlates directly with company viability as well as their own job security. In addition, safety is enhanced in the workplace with a PdM program. Predicting failure and removing or repairing equipment before failure occurs is the goal of PdM. This work is performed on a planned basis, with all the means to correct the problem in place. The ability of corrective actions to occur without distractions keeps yes on the job. Loss of focus is a cause of poor job performance or injury on a maintenance task.

American industry can’t afford to ignore predictive maintenance’s potential for long-term viability in a global economy. It gives us a chance to show what is possible and to lead the way into the future.

A caution for those on the ground, however: Documentation of PdM savings is critical for obtaining continued support of a predictive maintenance approach. How often have we heard about cutbacks in maintenance resources once a new plant management team comes on board at an organization? New management won’t have shared in the blood and sweat that went into getting your plant in the reliable condition it is in now. And if you don’t have proper documented justification of past savings and cost avoidances, you won’t have a good response when new management asks to know the value added by maintenance. If you worked hard to bring your plant to the reliable condition it’s in now, establish a routine to maintain it and a documentation process to justify the wins. You may be lucky enough to have supportive management now, but remind your team that the justification routine is not for today’s management; it’s for tomorrow’s management.