Sooner Or Later: Electrical System Failures

Invest in preventive maintenance, rather than a “run it till it fails” approach for electrical equipment.

By Michael J. Johnston
From the August 2018 Issue

Electricity is vital to society’s way of life. It enables the daily lives of citizens and allows businesses to thrive and be productive. This essential resource is taken for granted, often to a fault, in many circles. The “run it until it fails” approach is not a recommended philosophy when it comes to avoiding an outage and the associated costly downtime.

electrical equipment
(Photo: Courtesy of Valley Electric Company (VEC, Inc.))

Many believe that as long as the lights are on, there are no problems. A great approach for facility management relative to avoiding the dreaded outage is to understand and work toward achieving a planned outage of a known duration—in order to avoid an unplanned outage of unknown duration. This article takes a closer look at the importance of electrical system and equipment maintenance, preventive maintenance, and steps that facility owners and managers can take to keep the power operating normally.

Commissioning Electrical Systems

An important step in placing a building electrical system or equipment into service is commissioning. Many owners and specifying engineers require commissioning as part of the contract for a new project. The intent or purpose of commissioning is to ensure that all electrical equipment, components, sub-systems, and systems are installed according to contract documents, construction drawings, and specifications, to manufacturer instructions, and to industry-accepted standards, and that the equipment, components, sub-systems, and systems are complete, and that they receive adequate operational checkout and detailed testing, calibration, and adjustment by the installing contractor (general contractor or sub-contractors).

It is not the intent of commissioning to duplicate efforts or to require the general contractor or sub-contractors to perform any check or test twice. Checks and testing are expected to occur once in normal sequence of installation and startup procedures.

Commissioning building electrical systems is a systematic process of ensuring that all procedures, checks, and testing is rigorously executed and documented, and that all systems perform in accordance with the design intent and the owner’s requirements. This is achieved by verifying that the performance meets or exceeds the designer’s intent as documented in the project drawings and specifications.

The electrical commissioning process integrates the traditionally separate functions of equipment startup, control system calibration, testing and balancing, functional performance testing, documentation, and training. Commissioning could also include deferred functional and/or seasonal tests as approved or required by the owner.

The commissioning process does not reduce the responsibility of the installing contractors to provide a complete and fully functioning product. Any issues arising during the process which impact schedules, costs, or contractual obligations typically must be addressed by the owner or owner’s agent for resolution. In new construction, the owner’s agent could be the general contractor or electrical contractor. An essential part of the commissioning process is documentation. This serves as a baseline for a building owner and often provides specific information related to maintaining proper operation of the electrical system and connected equipment.

Deterioration Is Normal

Electrical systems and equipment are in a constant state of deterioration and wear from the time they are energized until the time they fail or are taken out of service for maintenance. What is meant by use of the term deterioration is usually insulation breakdown. Although in many cases the amount of deterioration or wear and tear on the conductors and equipment is sometimes minimal; nonetheless there will be some stress and wear over time. The amount of stress and deterioration is often directly proportional to the amount of load a system or equipment is carrying, and whether it is a continuous duty load or an intermittent one.

Maintaining an electrical system is an important step that can reduce the possibilities of failures and downtime. Preventive maintenance can include an expense, but should be viewed as an investment or insurance policy. Sooner or later electrical equipment that is not maintained will fail. When this happens, personnel safety and building safety can be affected. Electrical equipment failures can result in arcing events or explosions that can escalate into a fire and significant loss and downtime.

NEC Scope And Manufacturer Recommendations

The National Electrical Code (NEC) contains a general requirement in the scope that indicates it contains provisions necessary for safety of the installation. Compliance with the NEC rules and proper maintenance should result in an installation that is essentially free from electrical hazards, but not necessarily efficient, convenient, or adequate for good service or future expansion.

The NEC is the minimum set of requirements related to the electrical installation. Being the minimum, when the NEC is adopted into law, one must do at least that much. Many in the industry pay attention to the installation aspect of this scope statement but skim over the maintenance piece. Section 110.3(B) requires that listed electrical equipment be installed and used in accordance with any installation instructions included in the listing or labeling, which can include required maintenance. With the NEC including the word “used” in this section, it facilitates the use of any manufacturer’s instructions about maintaining the equipment for proper and continued safe use.

The NEC does not include many specific mandatory requirements for maintenance (though, there are a few that should be considered). What the NEC does include is requirements for installing essential electrical systems such as emergency systems, critical and life safety systems in healthcare, and uninterruptible power supplies (UPS) for electrical systems installed for critical operations power systems (e.g., data centers). These are few examples of systems for which the general maintenance language in NEC 90.1(B) has important meaning. Many lose sight of this.

There is another important NFPA standard related to proper equipment maintenance—NFPA 70B Recommended Practice for Electrical Equipment Maintenance. This is often not adopted into law by authorities having jurisdiction but can serve an essential role for building owners and facility maintenance personnel. The scope of NFPA 70B indicates that it applies to preventive maintenance for electrical, electronic, and communication systems and equipment. In the scope it is clear that manufacturer’s instructions are not trumped by the provisions in NFPA 70B. Systems and equipment covered by 70B are typical of those installed in industrial facilities, commercial buildings, institutional facilities, and even some large multi-family residential properties.

Electrical Safety And Best Practices

Maintaining electrical equipment and documenting that it is maintained according to manufacturer’s recommendations significantly reduces the possibility of system and equipment failures and injuries. Just the act of opening a large older piece of electrical equipment such as a switch or circuit breaker can result in failure and can even present an electrical safety hazard for those operating such equipment.

There is an important relationship between NFPA 70E Standard for Electrical Safety in the Workplace and NFPA 70B Recommended Practice for Electrical Equipment Maintenance. Equipment that is properly maintained in accordance with manufacturer’s requirements is less likely to present an electrical hazard, as described and covered by NFPA 70E, as in cases where equipment maintenance is neglected and run to failure.

A best practice is to be diligent about preventive maintenance, stay on schedule, and document periodic maintenance. Having maintenance records can assist greatly when hazard risk assessments must be performed. Another good practice to implement is to schedule periodic equipment and system infrared scanning processes to identify hot spots where potential failure is likely. This allows for a proactive scheduled outage to make repairs and avoid a failure.

There are important requirements in electrical codes, standards, and recommended practices that can be of tremendous benefit to those with the responsibility to maintain a building electrical system in full, safe operating order. If required periodic maintenance is ignored, sooner or later there will be a failure. Education and training are the keys to getting this right.

electrical equipmentJohnston is executive director of standards and safety for the National Electrical Contractors Association (NECA). He holds a BS in Business Management from the University of Phoenix, and is a member of the NFPA Standards Council and current Chair of the NFPA NEC Correlating Committee. Johnston is also secretary of the NECA Codes and Standards Committee. His career includes working as a journeyman electrician, foreman, and project manager. He also served as director of codes and standards for the International Association of Electrical Inspectors (IAEI) for over 10 years. Johnston is a member of the IBEW and is an active member of ANSI, IAEI, NFPA, SES, ASSE, the UL Electrical Council, the National Safety Council, and he is currently Chair of the NFPA Electrical Section.

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