You’re reading an outdated article. Please go to the recent issues to find up-to-date content.
Safety is an integral part of the electrical construction business and, as such, is an important shared responsibility between employers and employees. Implementing safety-related work practices is not optional. It is a requirement.
A trained and qualified work force is responsible for recognizing and avoiding workplace hazards. It is an essential part of establishing and maintaining a safe work environment. Qualified people must understand how to recognize and avoid electrical hazards by working on equipment and conductors only in the de-energized state.
Always disconnect the power before working on electrical conductors or equipment. This practice removes the electrical hazards and reduces the possibilities of injury or death. Why take chances when there is a safer way to perform the work?
Electrical industry cultural shift
Attitudes toward establishing an electrically safe work condition have evolved significantly over the years. In the 1940s, a common practice for testing voltages was a two-finger test. If we knew then what we know now, the industry would be further along with a better safety culture.
It is no longer acceptable to work “hot” or energized simply because it is inconvenient to shut off the power. Laws and safety standards mandate de-energizing the circuit and creating an electrically safe work condition as the primary means of protection; the first choice is to remove the electrical hazard(s). If energized work must be performed, it must be justified based on industry standards and safety regulations, following strict and safe work practices.
There are deep-rooted differences about de--energizing as the first choice before performing work on conductors or equipment, which is continuing to add to unacceptable injury and death statistics in the electrical industry.
According to the U.S. Department of Labor, an average of 9,600 serious electrical shock and burn injuries occur annually. In addition, there is about one electrocution per day. These statistics are unacceptable. In a study of electrical accidents, it was determined that most were associated with unacceptable and unsafe work practices and were avoidable.
The largest hazard is still electric shock, but arc flash injuries are the most gruesome, painful and life-changing. Such an injury can cause severe burns, scarring, tissue death, loss of limbs, blindness, hearing damage or loss, and more. The risk is far too great to keep taking chances and working on “hot” conductors and equipment; yet, many electrical workers continue this poor practice.
Performing unjustified energized work is more than a risk to the individual. An electrical shock or arc flash event that results in severe injury or death affects at least three entities: the electrical worker, his or her family, and the organization for which he or she works.
Arc flash events also can cause significant equipment and property damage. These risks are not worth it. The average cost of physical damage to equipment from this type of event is $50,000, while the cost of project delays, loss of electrical service and business interruption averages about $85,000 per incident.
Electrical safety programs
Section 110.3 of NFPA 70E 2012, the Standard for Electrical Safety in the Workplace, provides requirements for establishing and implementing an overall electrical safety program that directs activities suitable for the voltage, energy level and circuit condition(s). Key components of the program are the electrical safety program principles, safety controls, safety program procedures, hazard/risk evaluation procedures, job briefings and safety auditing.
Employers are responsible for providing safety-related work practices and policies and training employees to effectively implement these practices on job sites. Employees are responsible for learning the safety-related work practices and policies of the employer and for implementing them in daily operations on the job.
Achieving overall electrical safety is an important responsibility that employers and employees share. Both must contribute to obtain desired results. The safety-related work practices and procedures in NFPA 70E are intended to provide electrically safe work environments. Electrical workers must understand and apply basic safety requirements related to performing electrical work in a safe and efficient manner.
Employer and employee training are both necessary to attain compliance with the safety standards. Communication and education are the keys to an effective electrical safety program. It is important to reference NFPA 70E 2012 and to consult the applicable Occupational Safety and Health Administration (OSHA) regulations as needed to fully understand the minimum safety requirements that apply to both employers and employees.
Working energized or de-energized
It’s a common misconception that the question of whether to perform energized work is a decision one can make. The OSHA regulations and NFPA 70E are clear. With very few exceptions, the general rule prohibits working on energized circuits. The decision is already made. To perform energized work, one must justify to all responsible and liable parties why conductors and equipment cannot be de-energized. The decision to work “hot” is not for an individual to make nor is it a risk for an individual to take.
Establishing safe work environments
To work safely in any environment requires control of the hazards involved. The hazards associated with electrical work are shock and electrocution, arc flash, and arc blast.
The best choice for electrical workers is to always de-energize electrical circuits and equipment prior to working on them. Article 120 of NFPA 70E specifically addresses establishing an electrically safe work condition. Another guideline is the National Electrical Contractors Association’s (NECA) standing policy on safety, which indicates that, to achieve the goal of zero injuries in the workplace, employers and employees must work together to establish a zero-energy work environment whenever achievable.
There aren’t many circumstances that warrant working on energized circuits or equipment. Inconvenience is not an excuse to work on energized systems or equipment. The requirements in Section 130.2 of NFPA 70E indicate that circuits must be placed in an electrically safe work condition where employees are within the limited approach boundary or where employees interact with equipment where conductors or circuit parts are not exposed but an increased risk of injury from an exposure to an arc flash hazard exists.
Energized work is only permitted by exception where it is demonstrated that the task to be performed is infeasible in a de-energized state because of equipment design or operational limitations. It is a serious error and risk to confuse inconvenience with infeasibility. Contractors and employees must know the difference.
Examples of work that must be performed while the system is energized include testing (for example, troubleshooting operations or startup processes) of electric circuits that can only be performed while the circuits are energized. Testing a circuit or system for voltage or thermography (infrared scanning) is also a good example. Note that the process of establishing an electrically safe work condition (lockout/tagout) includes testing for the absence of voltage once the lockout/tagout process has been applied. Testing for the absence of voltage must be performed using an appropriate voltage detector and wearing the appropriate personal protective equipment (PPE) based on the amount of incident energy at the point the work must be performed.
Working while exposed to electrical hazards
The requirement for an electrical hazard analysis is covered in Section 130.3 and addresses arc flash hazards. This section provides the requirement for using an energized work permit in situations where it is determined that working on energized equipment or circuits are unavoidable. Section 130.4 addresses requirements for shock hazard analysis that must be performed. When working de-energized is infeasible or introduces increased risk or additional hazards, other requirements apply, including developing an energized work permit and properly protecting exposed employees with the appropriate PPE rated for the amount of incident energy involved. A good example of an acceptable energized work permit is provided in Annex J, Figure J.1. Additionally, Section 130.2(B) of NFPA 70E 2012 clearly states when an energized work permit is required and provides the exemptions from this requirement.
An important factor of performing justified energized work is to select the appropriate PPE based on the task involved and the hazard risk category based on the amount of incident energy in calories per centimeter squared. The amount of incident energy can be calculated using the formulas from IEEE 1584 and Annex D examples in NFPA 70E 2012. The required PPE also can be selected using the NFPA 70E Tables 130.4(C)(a) and the NFPA 70E “task-based” Tables 130.7(C)(15)(a) [Alternating Current] or 130.7(C)(15)(b) [Direct Current].
It is important to understand that the tables in Article 130 of NFPA 70E must be used in conjunction with the rest of the applicable rules in that article. The tables are not stand-alone references. Other requirements also apply. NECA offers a PPE selector, a task-based guide that provides the essentials of selecting the PPE suitable for the amount of shock hazards and incident energy involved. It simplifies the use of the applicable NFPA 70E tables to determine the required level of PPE for the job if justified energized work must be performed.
Regardless of past practices, it is not acceptable to work “hot” as a matter of convenience. Laws and standards mandate otherwise. Only by exception to this general rule should justified energized work be performed. If justified energized work is required, the appropriate level of PPE is required.
Always refer to applicable OSHA regulations and NFPA 70E for complete requirements for establishing an electrically safe work condition in addition to rules governing which work is not permitted to be performed energized.
JOHNSTON is NECA’s executive director of standards and safety. He is former director of education, codes and standards for IAEI; a member of the IBEW; and an active member of the NFPA Electrical Section, Education Section and the UL Electrical Council. Reach him at [email protected].
About The Author
JOHNSTON is NECA’s executive director of codes and standards. He is a member of the NEC Correlating Committee, NFPA Standards Council, IBEW, UL Electrical Council and NFPA’s Electrical Section. Reach him at [email protected].