Moisture, contamination and heat will deteriorate your electrical equipment over time so having a maintenance plan is a necessity. Your plan should prevent, retard or mitigate the harmful effects of these hazards, extending the longevity of your system. Determining the right maintenance strategy for you depends on risk and economic factors. With all of that in mind, should you choose reactive, preventative or predictive maintenance, or some combination of all three? In this article we explore the different maintenance strategies, including the benefits and drawbacks of each.
Which Maintenance Strategy Is the Best?
The answer is more complicated than you might think. Keeping in mind our goal, let’s first look at the different strategies or approaches to maintenance.
Run-To-Failure
Run-To-Failure (RTF) is not a maintenance strategy per se but more of a no-strategy approach. Degraded equipment is repaired or replaced only when the effect of degradation on process output becomes unacceptable. This is usually manifested in catastrophic failure. No explicit attempt is made to monitor performance or to avert failure, and the risks associated with ultimate failure are accepted. Because of the generally high reliability of electric power equipment installed in a benign environment, the RTF approach often provides satisfactory power reliability and availability in noncritical applications. This is also referred to as reactive maintenance.
Inspect and Service as Needed
Inspect and service as needed is a strategy one step up from Run-To-Failure. Operating or maintenance personnel inspect electrical equipment on a regular schedule. Under this approach, incipient failures are usually corrected before they become catastrophic, especially if the impact of a failure is considered unacceptable. There is often some informal monitoring of performance to predict future failures.
Preventative Maintenance
With the preventative maintenance strategy, established maintenance activities are performed at fixed intervals of calendar time, operating hours or operating cycles. Both procedures and schedules are usually based on manufacturers’ recommendations or industry standards. While the preventative maintenance approach ensures that equipment gets periodic attention, it does not necessarily prioritize maintenance according to safety or productivity significance, nor does it optimize the application of limited maintenance resources or take advantage of lessons learned from plant and industry experience. Preventative maintenance is currently the predominant approach among industries where productivity and safety are serious concerns.
Condition-Based Maintenance
The condition-based maintenance (CBM) strategy is also called predictive maintenance. It is an extension of the preventative maintenance strategy that uses nonintrusive monitoring and testing techniques to assess equipment condition. It utilizes planned maintenance tasks that are based on the equipment’s previous operating history and trending of the maintenance data. It is most effective when combined with a preventative maintenance program because it prioritizes maintenance based on the criticality of equipment, productivity, resources or lessons learned from experience.
Putting It All Together
The fact is none of these are a perfect solution. To accomplish our goal to prevent, retard or mitigate the effect of moisture, contamination and heat on our electrical equipment, it is best to customize a combination of all maintenance techniques to the specific application. We call this approach Reliability Centered Maintenance (RCM).
Let’s look at how this works with something almost everyone has — an automobile:
Run-To-Failure
- Wipers
- Lamps
Inspect and Service as Needed
- Fluids
- Belts
Preventative Maintenance
- Oil and Filter
- Exhaust
Condition-Based Maintenance
- Tires (tread measurements)
- Brakes (wear measurements)
Reliability Centered Maintenance
RCM in its original concept involved a heavy reliance on detailed failure modes and effects analyses; math-calculated probabilities of failure; and model development and accumulation of historical data. Because of the detail involved, it is highly labor-intensive, time-consuming and comparatively expensive.
The most appropriate applications of RCM are when the consequences of failure would result in a catastrophic risk to personnel safety and health, or to the environment, or could result in complete economic failure of an organization.
It is more realistic and cost-effective to adopt a streamlined RCM approach, recognizing its benefits while realizing that few building mechanical and electrical systems carry the catastrophic risk addressed in the rigorous RCM process.
Lower intensity more in line with the scale of a facility’s infrastructure also means lower costs. Streamlined RCM targets systems and components in order of criticality. It relies heavily on condition-based tasks and eliminates low-value maintenance tasks altogether based on maintenance and operations staff input and historical data.
Now you know why you need a maintenance program and which maintenance strategies are available. In the next article, you’ll find out how maintenance actually begins when the system is being designed and how you can ensure reliability before you even break ground on construction. If you’re ready to maximize the reliability of your system and ensure compliance with industry standards,
contact us!
Check out the first article in this four-part series on Reliability Centered Maintenance!
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