Protecting Yourself from Arc Flash Hazards
Oct 18, 2014Dave Kreger | Electrical Construction and Maintenance
Nine things every electrical professional needs to know
Arc flash is the leading cause of serious injuries and deaths on the job in the electrical industry. In fact, as many as eight out of 10 electrical injuries are caused by burns that result from exposure to energy released from an arcing fault. Additionally, the
Institute of Electrical and Electronics Engineers (IEEE) reports that 2,000 workers are admitted to burn centers for extended injury treatment caused by arc flash each year. Even someone standing more than 10 ft from the fault source can be fatally burned. If your work requires you to install, inspect, operate, or maintain live electrical equipment — or work near such equipment — then you’re at risk for arc flash-related accidents and injuries. The frequency of arc flash-related incidents and the severity of the consequences have incited organizations, including the Occupational Safety and Health Administration (OSHA) and National Fire Protection Association (NFPA), to create new and more stringent requirements to protect employees and contractors working on or near live electrical equipment. Specifically, OSHA recently published its first-ever arc flash protection requirements for the electric power generation, transmission, and distribution industry, making significant changes to electrical safety requirements in high-voltage environments. Electrical workers need to play an active role in protecting themselves when working near energized equipment. In addition, the latest version of NFPA 70E: Standard for Electrical Safety in the Workplace has made changes to safety, maintenance, and training requirements. Changes were made to the ways in which electrical risks are evaluated to help prevent exposure to electrical arc flash hazards and to support compliance with OSHA requirements. How to Reduce Electrical Hazards in the Workplace Managing Arc Flash in Your Facility While employers are obligated by law to follow OSHA regulations for creating a safe work environment, electrical workers need to play an active role in ensuring their own safety on the job. This includes adhering to OSHA requirements and following the specific safety procedures and practices for working on live electrical equipment as outlined in NFPA 70E. The following best practices reflect the latest codes and standards. Keeping these in mind can help keep you safe at work and could even save your life.
Tip 1: Know what you’re dealing with, and get it on paper. Obviously, choosing to work on or near live electrical equipment increases your risk of exposure to an arc flash. You have both a right and a responsibility to understand those hazards. While OSHA and NFPA have long required employers to meet with contractors prior to work starting in order to communicate those hazards, NFPA 70E added a requirement in 2012 stipulating that the meeting between the employer and contractors must be documented. Documenting the meeting helps to ensure and validate that you have the information you need to stay safe on the job.
Tip 2: Understand arc flash severity and calculated boundaries. As part of the meeting between employers and contractors, employers must now provide contractors with information they need to make safety-related assessments, including arc flash severity and calculated arc flash protection boundaries. NFPA 70E requires employers to complete an arc flash risk assessment to determine if an arc flash hazard exists and to determine the arc flash boundary. This information allows contractors to make decisions related to the use of safe work practices and techniques and to select personal protective equipment (PPE) necessary to mitigate the risks. In the past, NFPA 70E was ambiguous about if it was sufficient to use tables supplied by the standard for the arc flash boundary distance (flash protection boundary) or if the distance would have to be calculated. However, several provisions in the latest version of NFPA 70E make it more difficult to defend the easier method of using the tables, especially for locations where the voltage is greater than 50V. The newest revision to 29 CFR 1910.269 requires owners/employers to estimate incident energy and even recommend the methods to use in certain circumstances, such as adhering to IEEE Standard 1584 for equipment operating up to 15,000V and using special analysis software for higher voltages. By calculating the boundary and providing you with the information, your employer ensures you understand when and at what distances PPE and safe work practices are needed to protect against arc flash hazards.
Tip 3: Be sure you are qualified for the job, and get training if you need it. NFPA 70E 2015 defines a qualified person as one who has demonstrated skills related to the construction and operation of the electrical equipment and installations and has received safety training to identify and avoid the hazards involved. Per revisions to NFPA 70E in 2012, only qualified persons can perform testing and maintenance within the limited approach boundary. Employers need to make sure that employees and contractors who work around (not just on) energized electrical equipment are safety trained, that retraining occurs at least every three years, and that the training content is documented. Electrical equipment operators, who may not necessarily be considered “qualified” electrical workers, need specific training to identify when PPE is required to operate (switch) electrical devices. Additionally, managers need to assess the safety training program effectiveness through auditing field work at least once a year to ensure compliance with NPFA 70E. While both OSHA and NFPA 70E require employers to provide and validate safety training, it is ultimately up to the individual worker to determine if he has the knowledge and skills needed to safely perform work on electrical equipment. In other words, if you’re not qualified for the job, don’t do it until you are properly trained.
Tip 4: Look for a sign. Read and understand arc flash labels. The 2002 edition of the National Electrical Code (NEC) introduced the requirement for marking flash hazards on electrical equipment in the field whenever the possibility of energized work exists. The information on these labels is designed to help workers make intelligent choices when selecting appropriate PPE. The latest editions of NFPA 70E spell out the types of equipment that need to be labeled, specifically switchboards, switchgear, panelboards, industrial control panels, meter socket enclosures, and motor control panels that are likely to require examination, adjustment, servicing, or maintenance while energized. Furthermore, the language of NFPA 70E 2015 has been slightly modified regarding what information needs to be included on field labels, stating that the labels should include: • Nominal system voltage • Arc flash boundary • At least one of the following: – Incident energy and working distance or arc flash PPE category (but not both) – Minimum arc rating of clothing – Site-specific level of PPE. If this information is not clearly available, contractors should inform the owner of the electrical equipment. NFPA 70E clearly indicates that electrical equipment owners are responsible for documentation, installation, and maintenance of the field-marked labels.
Tip 5: Dress the part. Use new arc flash PPE tables to choose arc-rated clothing and other PPE. NFPA 70E 2015 introduces a new format for selecting the appropriate arc-rated clothing and PPE for both AC and DC systems. In the past, the table method was somewhat cumbersome, and the new format is designed to simplify the process. Specifically, new task-based tables have been added for determining when arc flash PPE is necessary. For each task, the table indicates if there is an arc flash hazard (yes or no). The new table addresses risk but not severity of the exposure. For example, when you are operating a power circuit breaker after it has tripped and no true reason for the trip was discovered or corrected, PPE is required. However, it will take further engineering analysis by you or your employer to determine what type of PPE is required.
Tip 6: Make it safe. Verify an electrically safe work condition. Workers need to test and verify that a system is de-energized, including the lockout/tagout procedure. During this work, equipment is considered to be energized and workers must be informed of the level of PPE necessary for the job. Furthermore, NFPA 70E 2015 stipulates that workers need to use an adequately rated test instrument to test each phase conductor or circuit part to verify it is de-energized. Before and after each test, workers need to verify that the test instrument is operating satisfactorily through verification on a known voltage source. Test equipment manufacturers are labeling their equipment with the energy category for each device, and only Category III or IV instruments should be used on industrial electrical systems. While there might be many available “live” sources for verifying operation of a low-voltage instrument, higher voltage test points may not be available. The manufacturers of high-voltage measuring and detection devices also offer a separate portable test source to verify operation.
Tip 7: Get permission. Know when an energized electrical work permit is required. NFPA 70E 2015 states that an energized electrical work permit is required to be within the restricted approach boundary (RAB) or when interacting with an increased risk of exposure to an arc flash. This permit is a critical tool in helping workers determine the risks involved in performing a specific job or task. The permit needs to be carefully reviewed and signed by those authorizing the task, especially in instances when the work is not routine in nature, meaning that it’s performed less than once a year. The need for an energized electrical work permit is exempted when qualified persons are performing tasks such as testing, troubleshooting, or voltage measuring; thermography and visual inspection up to RAB; access/egress with no electrical work within the RAB; and general housekeeping up to RAB. Keep in mind that these exemptions are contingent upon the worker being qualified and on following appropriate safe work practices and using the necessary PPE.
Tip 8: Be well equipped. Use GFCI protection where required. In 2012, NFPA 70E added a requirement for the use of ground fault circuit interrupters (GFCIs) where required by local, state, and federal codes or standards. The 2015 version of the standards adds to the requirement by stipulating that GFCI protection needs to be provided for operating or using tools related to maintenance and construction activity with 125V/15A, 20A, or 30A circuits. At voltages greater than this, either GFCI protection or assured equipment grounding conductor program must be provided. Ask to review the written description of this program that is required by OSHA to be at the job site. The description should not only outline the required equipment inspections, tests, and test schedule, but should also include specific procedures adopted by the employer. If any questions or concerns arise, you may want to follow up with the person who has been designated by the employer to implement the program.
Tip 9: Know the status. Make sure electrical equipment has been maintained. To ensure safety, NFPA 70E added requirements in 2012 for conducting maintenance on electrical equipment. Previously, maintenance was only specified for overcurrent protective devices. Per the new requirements, a single-line diagram needs to be kept current and maintained in a legible condition, and all electrical equipment must be maintained in accordance with manufacturers’ instructions or industry consensus standards to reduce the risk of failure and the subsequent exposure of employees to electrical hazards. In addition, documentation is now required for overcurrent protective devices to show they have been maintained, tested, and inspected in accordance with manufacturers’ instructions or industry consensus standards such as ANSI/NETA 2011 Standard for Maintenance Testing Specifications for Electrical Power Distribution Equipment and Systems and/or NFPA 70B: Recommended Practice for Electrical Equipment Maintenance.” Per NFPA 70E 2015, the equipment owner (or the owner’s designated representative) is responsible for maintaining the electrical equipment and documents. To help employees assess the overall status of electrical equipment maintenance, test or calibration decals can be applied to the equipment to indicate the test or calibration date and overall condition of equipment. Contractors must consult these decals to see the last maintenance date and whether or not the equipment was found to be acceptable at that time. OSHA requirements and NFPA 70E are designed to reduce arc flash hazard risks and save lives. Employers are required to provide workers with safe working conditions along with the information, tools, and PPE they need to stay safe on the job. However, it is the responsibility of each individual worker to play an active role in ensuring his or her own safety. Understanding the latest NFPA 70E requirements, working together with your employer to better assess electrical risks, and complying with safety requirements will go a long way in keeping you protected at work and reducing the potential for devastating loss.