Article reprinted from Electrical Contractor Power and Integrated Building Systems
Preventive maintenance plays an important role in how long a product will provide trouble-free service and, ultimately, how long it will last. Nothing lasts forever, so the saying goes, but with some care and regular servicing and maintenance, products can provide normal anticipated operation. A good example of maintenance that lengthens life expectancy is a vehicle. When a new vehicle is purchased, there is usually a scheduled maintenance plan established by the manufacturer to ensure the vehicle performs as expected and lasts. Of course, driving habits and attention to preventive maintenance schedules and manufacturer’s recommendations are factors that can determine how the product will perform and for how long. This article reviews some of the principle techniques used in preventive maintenance operations and reasons for establishing an effective preventive maintenance program and staying committed to it.
In the electrical industry, preventive maintenance is equally important as vehicle maintenance, if not more so. However, there is significant complacency out there and often an expectation from society that, once an electrical system installation is complete, it will provide adequate performance over the life of the system. Preventive maintenance is essential for electrical equipment. Lack of or ignoring electrical maintenance is often directly related to failures that can trigger unwanted downtime or even cause severe injury or death. The problem is that facilities maintenance staff often ignore or bypass the regular or routine preventive maintenance procedures and techniques that can minimize these unwanted consequences.
Justification for preventive maintenance programs
Electrical systems and electrical equipment deterioration is normal, and failure is inevitable over time. Failure from deterioration is typically a slow process, but severe conditions; overloading of systems, circuits and equipment; and excessive duty cycling can all accelerate the deterioration process. However, an effective preventive maintenance program can delay failure. Often, it is challenging to establish and maintain a reasonable budget for maintaining electrical equipment and systems. If everything is working, there is no problem. The whole idea behind a preventive maintenance program is to prevent anticipated failures. This is accomplished through regularly servicing equipment, identifying replacement intervals and scheduling outages to perform the replacements.
Planned investment in preventive maintenance procedures and techniques pays dividends in the long run. However, many don’t view it that way and choose to operate their electrical system and equipment to the point of failure, at which time, the expense can be extreme. It is always best for your customers to plan for it in the facility’s operations and budget. Obviously, an effective preventive maintenance program requires support and buy-in from management in addition to allocated funding.
There are two primary benefits from implementing effective preventive maintenance in a facility: (1) the direct benefits of preventive maintenance programs in the reduced costs of repairs and minimized or eliminated downtime and (2) safety for personnel and property damage. The first item is far easier to measure than the second, as it is hard to predict how a failure in electrical equipment may cause injury or death, but it can happen. Chapter 2 of NFPA 70E, Standard for Electrical Safety in the Workplace, provides important safety-related maintenance requirements. An effective preventive maintenance program provides various management responsibilities that will help keep repair and replacement costs down and production at desired levels.
Developing an effective program
Good economic judgment is necessary for developing an effective electrical preventive maintenance program. As indicated earlier, two objectives of such a program should be focused on enhancing safety and reducing equipment failure and loss. A crucial element is having responsible and qualified personnel to understand and implement the program. The program should include regular inspections, periodic testing and servicing of equipment, and effective record-keeping. When developing an electrical preventive maintenance program, a thorough survey and analysis will identify equipment and systems that are essential and will itemize them into a hierarchy of importance. Once the priorities are established, appropriate schedules can be developed. There are four basic steps that should be taken to develop an electrical preventive maintenance program. First, compile a list of electrical equipment in the facility. Second, determine which equipment is most critical for the operation. Third, implement a monitoring system for length of use and duty cycles, and identify signs of failure or fatigue. And fourth, determine the staffing needs and expertise of personnel that will perform the service and maintenance operations.
Electrical equipment—including motors, transformers, circuit breakers, switches, motor starters and so forth—should be thoroughly inspected and evaluated to determine where in the program they must be placed. Some good processes to implement during this analysis are identifying any visible deterioration, checking operating temperatures, visually inspecting electrical connections and verifying the connected load on equipment.
Another effective process to implement is infrared scanning of terminations to identify hot spots that may need attention and service. Thermography equipment can be expensive but can really be worth the investment. Since some facility managers may opt to not purchase this equipment or train personnel in its use, some savvy contractors provide these services. Another important aspect of equipment maintenance is to follow manufacturer’s guidelines for preventive maintenance.
Training and safe work practices
Contractors performing periodic maintenance and service of electrical equipment should have a thorough understanding of the electrical field and should be trained and familiar with the equipment and systems they must maintain and work on. Qualified and trained personnel understand the construction and operation of equipment and installations, and they have safety training to recognize and avoid the hazards involved. The definition of qualified person is the same in the National Electrical Code (NEC) as it is in NFPA 70B, Recommended Practice for Electrical Equipment Maintenance. This means that these people are familiar with how the equipment works and how to safely service and maintain it. Additional training may be necessary to achieve minimum competency levels. Employees should be trained in the proper use of tools and test equipment, specific work methods and techniques, job planning to safely perform the tasks, proper voltages, and proper use of personal protective equipment, to name a few. Training of staff that performs preventive maintenance operations and procedures is essential. It is important to identify training deficiencies and provide the necessary training.
In addition to training, preventive maintenance operations and tasks often require specific tools and test instruments. It is important that these types of equipment be maintained in top condition and working condition, specifically when it comes to electrical testing instruments. Additionally, specific training on the use of electrical testing instruments may be necessary for safe and effective use.
Instructions, schematics and single-line diagrams
Maintaining accurate records is an essential part of an effective preventive maintenance program. Some key documents that should be available, maintained and kept current are single-line diagrams for the facility, schematics for the connected equipment or machines in the facility, and any manufacturer’s instructions that deal with installation and maintenance requirement. Having these documents and keeping them current can be a demanding part of preventive maintenance, but good administrative skills and practices can be valuable in timesaving and efficient plan implementation.
The NEC is an installation code that is primarily prescriptive-based rather than performance-based. This means the rules contained in the Code are prescribing how to install equipment or systems to achieve desired or required performance. The NEC does have some performance requirements that relate to preventive maintenance programs or process. One such requirement is provided for emergency systems in Section 700.3, Tests and Maintenance. This section requires periodic testing on a schedule acceptable to the authority having jurisdiction to ensure that the emergency system is maintained in proper operating condition. This is an extremely important requirement, as the system must operate in an emergency. Emergency systems that have a generator as a power source are usually exercised periodically, either manually or by automatic exercisers. Similar requirements apply to battery-powered emergency systems. Written records must be kept of the periodic testing. The last thing a facility needs is a nonfunctioning emergency system during an actual emergency. Preventive maintenance programs can reduce the possibilities of system failures or failure to start and operate when called on. Similar periodic testing and maintenance requirements in the NEC also apply to legally required standby power systems (701.3) and critical operations power systems (708.6).
Many organizations have implemented effective preventive maintenance programs to their benefit. However, some owner and facility preventive maintenance programs are deficient, often to the point of failure that results in unwanted or costly downtime. Preventive maintenance is often ignored and considered too expensive to implement. In reality, it is a valuable investment that is measurable. Preventive maintenance can help avoid equipment failure, alleviate repair and replacement costs, and increase safety for personnel. It should not be treated as an unnecessary investment.
The NEC includes mandatory requirements for periodic maintenance of essential power systems. While preventive maintenance is not required for general, nonessential loads, it is recommended.
Various resources with information about preventive maintenance programs are available—some simple, some really complex. Refer to the information in NFPA 70B, Recommended Practice for Electrical Preventive Maintenance, for more detailed information about effective programs.