December 22, 2016 - Maintenance & Operations
In an increasingly competitive business environment, maintenance and engineering managers are often challenged by upper management to increase revenue and reduce expenses in their institutional and commercial facilities.
Operating expenses are often targeted, which can actually have a reverse impact on the bottom line. For example, in many cases, the maintenance budget for electrical infrastructure is reduced because electrical equipment is sometimes “out of sight, out of mind,” increasing the likelihood of costlier repairs.
The case for electrical maintenance
The definition of electrical preventive maintenance (EPM), per National Fire Protection Association (NFPA) 70B: Recommended Practice for Electrical Equipment Maintenance is, “A managed program of inspecting, testing, analyzing, and servicing electrical systems and equipment with the purpose of maintaining safe operations and production by reducing or eliminating system interruptions and equipment breakdowns.” (2016 Edition)
Managers must understand what the monetary impact of an unplanned outage means to their operation. However, when an event happens, the focus is usually on restoring power as quickly as possible and at all costs. Often, the tangible and intangible costs are not accounted for during the event. According to NFPA 70B-2016, Section 4.1.3, “Without an EPM program, management assumes a greatly increased risk of a serious electrical failure and its consequences.”
The aforementioned consequences do not only include financial costs. Worker safety is of far greater importance. A common cause of accidents is workers being placed in harm’s way. Exxon-Mobil conducted a study on maintenance-related accidents. The findings revealed a five times greater incidence of accidents when working on unexpected equipment failures than on planned, corrective jobs.
Relative to costs, Section 4.2.1 of NFPA 70B-2016 states, “A well-administered EPM program reduces accidents, saves lives, and minimizes costly breakdowns and unplanned shutdowns of production equipment. Impending troubles can be identified — and solutions applied — before they become major problems requiring more expensive, time-consuming solutions.” A simple everyday illustration is changing the oil in a car. A relatively minor expense every few thousand miles reduces the risk spending hundreds on engine repair.
With the case for keeping maintenance budgets intact now established, where to begin? The traditional viewpoint has been time-based maintenance activities, based upon manufacturer’s recommended guidelines. For electrical distribution equipment, the industry-accepted OEM frequency is once every three years. If equipment is installed in harsh or extreme operating environments, the maintenance schedule is mostly likely more frequent.
Fast forward to today’s increasingly complex, automated and connected systems. Developing the proper maintenance strategy can be a quite an undertaking, given the different types and manufacturers of equipment with a facility. Refer back to NFPA’s definition in paragraph two and note the use of the word systems. Keep in mind that any individual maintenance on separate pieces of equipment or components does not ensure a completely coordinated and reliable power system. Reliable electric power depends on all components within the system operating properly.
The goal: Safe, reliable power
In general terms, reliability is a property of an electrical power system that describes the likelihood that the system will successfully operate or perform as designed, constructed, and intended. Calculating the reliability of electrical equipment is more of a mathematical probability than an actual physical condition. In the most basic terms, if a piece of equipment is designed to continuously operate “X” years and it does, it is 100 percent reliable to “X” years. After that point in time, if there is an occasional breakdown, the reliability beyond the stated time is less than 100 percent.
An electrical system is as reliable as its weakest link. The more complex the system, the higher the risk of unplanned downtime. Think of each piece of equipment as one in a series, each with its own reliability rating percentage. It appears the series is 90% reliable, right? Actually, the reliability for this series is: 0.9 x 0.9 x 0.9 x 0.9 = .656 or 66%.
Managers may be unaware of the current reliability state of their electrical power system unless maintenance and test inventory data on all equipment is complete and readily available throughout the equipment’s service life. If documentation is unavailable or outdated, management may consider having a power system assessment performed by a professional engineer. A power system assessment determines the current state electrical system, its associated equipment, its functionality, and its reliability relative to the present needs of a facility’s functions and operations.
Reliability vs. reality
When budgets are tight and processes are critical, a reliability-centered maintenance (RCM) strategy may be a viable consideration. RCM focuses on the operation of the power system as a whole by identifying the functions and failure modes of assets that are most critical. Maintenance tasks are then determined and prioritized to minimize the possibility of failure. RCM enables facility management to make quantifiable decisions on maintenance costs, while increasing power system reliability.
RCM integrates preventive maintenance, predictive testing and inspection, run-to-fail and proactive maintenance techniques. Power system components are analyzed using the RCM decision tree, which yields four possible outcomes for any subsystem or component:
Implementing RCM is a multi-faceted, multi-functional process and requires an ongoing commitment. Companies looking to implement RCM should refer to the standard SAE JA1011, Evaluation Criteria for Reliability-Centered Maintenance Processes.
Conclusion
Even though reactive maintenance activities typically cost three to four times more, planned maintenance activities are often deferred due to high productivity objectives and tight maintenance budgets. An interactive calculator is available to assist electrical professionals in estimating applicable savings by increasing planned maintenance activities.
Whether the selected maintenance strategy is preventive, predictive, condition-based, or reliability-centered maintenance, proper planning and adequate resources are crucial. These include test equipment, personal protective equipment (PPE) and tools, and qualified personnel to carry out the maintenance tasks. An effective record keeping system — whether computerized or manual — is essential so testing results can be used over time to analyze trends.
Electrical outages are costly. They consume valuable production time, may cause equipment damage and, worst case, injuries to personnel. When it comes to electrical reliability, help ensure 2017 is safe and prosperous by making room in the OPEX budget for planned maintenance activities, and having a strategy in place that will optimize the spend and reduce unplanned downtime.
Jeramy Freeman has more than 10 years of professional experience in sales, marketing strategy, offer development, and product marketing with Schneider Electric. He earned a BS in Electrical Engineering and an MBA with a specialization in Marketing from North Carolina State University.
