The four fundamental principles of effective electrical equipment maintenance are ensuring it remains dry, clean, cool, and tightly connected. Adhering to these principles helps prevent or reduce the rate of deterioration in electrical power and control systems. However, the degradation of electrical equipment is inevitable, and, if neglected, can result in electrical breakdowns and issues. To address these problems, a robust Electrical Preventive Maintenance (EPM) and testing program must be established to minimize potential accidents, unscheduled outages, and equipment breakdowns. Various philosophical approaches to electrical maintenance exist, including reactive maintenance, predetermined maintenance, predictive maintenance, proactive maintenance, reliability-centered maintenance, and smart maintenance. In this article, we will explore these approaches and strategies for maintaining electrical assets to enhance overall operational efficiency and workplace satisfaction.
Before delving deeper into the discussion, it is essential to define what maintenance entails. According to the British and European standard for maintenance management, EN 13306:2001, maintenance is defined as:
| "The combination of all technical, administrative and managerial actions during the life cycle of an item intended to retain it in, or restore it to, a state in which it can perform the required function." |
Meanwhile, the role of maintenance management is to determine maintenance objectives, strategies, and responsibilities, as well as execute consciously selected action plans to meet overall organizational and maintenance objectives. The standard also provides two crucial definitions for maintenance objective and maintenance strategy:
To reduce the likelihood of failures, unexpected interruptions, and equipment malfunctions, implementing an effective Electrical Preventive Maintenance (EPM) program is crucial. Both direct and indirect benefits can result from a well-executed and planned EPM program. Direct benefits include lower maintenance costs, reduced delays, and enhanced safety. Indirect benefits include improved worker satisfaction, superior workmanship quality, increased output, and better understanding of system flaws that stem from either system design or subsequent changes. In summary, a robust EPM program boosts overall engaged productivity and worker satisfaction while decreasing the risk of equipment failure. The various electrical power system devices and related equipment should undergo regular inspections, tests, repairs, and services as part of an effective EPM program. This can be achieved by establishing a maintenance department or outsourcing the work to a private company or independent contractors.
In maintaining electrical assets, it's essential to comprehend the various types of failures that can occur. This knowledge aids in determining when maintenance interventions are needed and which interventions are most suitable. There are five common types of failures in maintenance: functional, performance, degrading, catastrophic, and incipient failures:
Reactive or corrective maintenance follows the philosophy of "fix it when it breaks," also known as run-to-failure (RTF) or breakdown maintenance. With this approach, damaged equipment is only repaired or replaced when its impact on the process output becomes intolerable, usually when a major failure occurs. Small businesses without specialized maintenance personnel and larger, more sophisticated businesses with non-critical machinery and systems often use reactive maintenance.
Reactive maintenance is a fire brigade approach that accepts the risks of potential equipment failure without monitoring its performance or mitigating failure. Therefore, businesses should ask several questions to determine whether implementing corrective maintenance alone is sufficient, such as how the failure of a machine affects production, the impact of a sudden loss of a crucial function on the organization's overarching objectives, significant safety or cost considerations driving maintenance policy, and how a breach affects the maintenance department's reputation or the organization's profitability.
The "inspect and service as necessary" approach to maintaining electrical equipment is an improvement over the "run-to-failure" approach. In this approach, electrical equipment undergoes periodic inspection by plant operating or maintenance personnel, typically during routine plant visits. When the consequence of a failure is deemed unacceptable, it is standard procedure to fix it before it progresses to a disastrous level. This strategy strikes a balance between reactive maintenance and more proactive measures like predictive maintenance, making it a popular option for many industrial plants. It is widely used in numerous industrial production facilities. This strategy reduces equipment failure risk and downtime while remaining cost-effective for many companies by performing periodic equipment inspections and addressing issues before they become disastrous.
Predetermined maintenance is a time-based maintenance (TBM) approach, also referred to as scheduled, historical, calendar, or cycle-based maintenance. With this approach, predetermined EPM tasks are performed at regular intervals based on the schedule, working hours, or operational cycles. Predetermined maintenance activities are carried out on an ongoing basis by assigning lifetime distributions to components based on experiences, evaluations, manufacturers' recommendations, or industry standards.
While this strategy ensures that equipment receives regular checks, it does not always prioritize EPM based on its importance for safety or efficiency. It may also not make the best use of the limited EPM resources available or utilize the knowledge gained from plant and industry experience. Despite its drawbacks, scheduled EPM remains a favored approach among experienced plant operators where productivity and safety are significant concerns.
Predictive maintenance, also known as condition-based maintenance (CBM), relies on methods that can provide early warning signs of deterioration. This method also uses historical operating data in addition to trending maintenance data to anticipate equipment failures. Condition-based maintenance (CBM) combines condition monitoring, inspection, testing, analysis, and the necessary maintenance procedures. The primary goal of the CBM approach is to make maintenance decisions based on the asset's condition.
However, condition monitoring does not increase machine reliability or delay failure; it only informs us of its operational status so that we can prepare in advance to address any maintenance requirements. Implementing condition-based maintenance requires the ability to identify reduced failure resistance associated with any identified failure mode, unambiguous definition of potential failure conditions detectable by systematic and explicit tasks, and a reasonably consistent time interval between potential failure and actual or functional failure.
In contrast, proactive maintenance focuses on preventing equipment failure by improving design, installation processes, quality control, and scheduling of maintenance tasks. It adopts a life-cycle approach to maintenance and ensures that improvements resulting from best practices and experiences gained are incorporated into future designs and processes. Proactive maintenance also involves conducting forensic assessments to identify the root causes of equipment failures. To maximize maintenance efficiency, it integrates maintenance support activities into maintenance scheduling and employs RCM and predictive technologies.
RCM (Reliability-Centered Maintenance) is an approach to maintenance that aims to maximize equipment reliability and availability by integrating equipment condition, criticality, failure history, and life cycle cost to develop the most efficient maintenance techniques for each system, subsystem, and component. RCM is becoming increasingly popular compared to other maintenance techniques because it utilizes the advantages of four separate maintenance approaches: reactive, preventive, predictive, and proactive. To reduce the uncertainty associated with equipment reliability, it is an ongoing process that continuously redefines and refines each maintenance action.
RCM evaluates equipment condition regularly and uses the appropriate tools to calculate the margin to failure, deviations from the baseline, and actual equipment condition. This enables maintenance and operations personnel to pinpoint the most likely source of a problem down to the component level and assess the risk associated with continuing operation or maintenance postponement. Most of the time, condition testing like thermographic inspection is non-intrusive, allowing equipment condition assessments to be conducted while the equipment is in service and under load. RCM ultimately aims to achieve the ideal combination of the four maintenance approaches mentioned earlier to maintain optimal equipment reliability and availability.
Smart maintenance integrates all maintenance participants (or production assets), regardless of their physical location, into the overall maintenance function and the overall business function. It is sometimes referred to as connected PdM because, through the implementation of cloud-based services, IoT/IoS, and big data, among others, the production asset, on-site and remote engineers, and operation staff are all connected. Smart maintenance typically includes the use of sensors, data analytics, and machine learning algorithms to monitor equipment status in real-time, anticipate potential issues, and determine the most suitable maintenance techniques to minimize downtime and maximize equipment lifespan.
Since smart maintenance systems can be monitored remotely, technicians can receive real-time updates and notifications from any location. This enables operations and maintenance personnel to respond more quickly and effectively since they can immediately assess issues even if they are not on-site. Smart maintenance systems can automate various maintenance activities, such as scheduling periodic inspections or issuing work orders whenever specific criteria are met. As a result, technicians may be able to focus on more complex tasks and identify issues more quickly.
Smart maintenance can benefit a wide variety of assets, including building sites, transportation networks, energy infrastructure, and manufacturing machinery. It is an essential enabler of the digital transformation of maintenance, and as more companies use digital technology to streamline their maintenance operations, its importance will only grow in the coming years.
In conclusion, electrical preventive maintenance is crucial for ensuring the safety, reliability, and efficiency of electrical equipment. Implementing an effective EPM program can significantly reduce the risk of accidents, unplanned shutdowns, and equipment failure while improving operational efficiency and workplace satisfaction. There are different philosophical approaches to electrical maintenance, and each approach has its advantages and disadvantages. Selecting the right approach depends on various factors such as asset criticality, equipment reliability, and maintenance costs. The RCM approach is favored by many companies; however, most power utilities, manufacturing firms, and owners of plant facilities utilize a combination of these approaches. Ultimately, the goal of any maintenance program should be to minimize equipment downtime and maintenance costs while ensuring the safety and reliability of electrical equipment.