Linden, AL – Linden Lumber has been cited for two repeated and seven serious safety, health, and LOTO violations. OSHA found that workers were exposed to falls and unguarded belts, pulleys and machinery, according to their Oct 13, 2015 report. The Alabama lumber mill faces fines totaling $43,116 for continually exposing workers to potentially deadly workplace safety hazards that could cause amputations, falls and other injuries.
“It’s disappointing when employers that have been previously cited for safety violations continue to expose workers to those same hazards,” said Joseph Roesler, director of OSHA’s Mobile Area Office. Linden Lumber was previously cited for similar violations at this facility in February.
OSHA opened the inspection after learning of a worker being hospitalized for a broken leg when an overloaded piece of machinery shot out a piece of lumber. This inspection that occurred in May fell under OSHA’s National Emphasis Program on Amputations..
Serious citations were also issued to the employer for failing to provide safety procedures to prevent machinery from starting up during maintenance and servicing; not providing protective eyewear to workers; and improper storage of compressed gas cylinders. Additionally, the employer exposed workers to falls and multiple electric shock hazards.
Bristol, PA – An OSHA inspection at Covanta’s Bristol (PA) incinerator found 16 serious violations of workplace safety and health standards. The waste combustion facility is facing a $80,000 fine for dangerous workplace practices. energy-from-waste, waste-to-energy plant, waste combustion
The investigation was spurned by an employee complaint to OSHA. The violations include toxic metals in ash, the dangers of falls or working in confined spaces, and electrical and mechanical hazards.
In its finding, OSHA said Covanta “needlessly exposed its employees to the hazards of electrocution, fire, falls, slips and trips, crushing, being trapped or overcome in a confined space, eye injuries and cancer, lung or kidney damage.”
In July 2011, it also paid a $400,000 fine penalty after its Connecticut burn plant sent toxic dioxins into the air. It also paid a dioxin emissions fine in 2009.
The company said it intended to contest the OSHA’s findings. “The health and safety of employees is our priority at Covanta so we take the recent citations at our Bristol facility very seriously,” said a spokesman. “We have reviewed the citations closely and have filed a notice to contest because we disagree with the assertions made by the OSHA.”
Winesburg, OH – Case Farms chicken producing and processing company has been placed in the Severe Violator Enforcement Program of the U.S. Department of Labor’s Occupational Safety and Health Administration after the agency issued more citations and $861,500 in fines this week.
Case Farms is the leading supplier of chicken to national fast food and supermarket brands. In its inspection, OSHA found that Case Farms employees “are exposed to the dangers of amputation, electrocution, and hazardous falls on a daily basis.”
Case Farms was issued two willful, 20 repeat, 30 serious, and three other-than-serious safety and health violations. The violations stem from an inspection in February that found amputation hazards, lack of personal protective equipment, and numerous violations of electrical safety standards, among other violations.
In a press release, Dr. David Michaels, assistant secretary of labor for OSHA stated:“Case Farms is an outrageously dangerous place to work. In the past 25 years, Case Farms has been cited for more than 350 safety and health violations. Despite committing to OSHA that it would eliminate serious hazards, Case Farms continues to endanger the safety and health of its workers. This simply must stop.”
Case Farms issued the following statement in response: “We do not agree with the negative characterizations that have been made about our company and our employees” by OSHA. The company said it has 930 employees at the Winesburg facility, and its last lost-time injury there was on Sept. 16, 2014.
Despite this safety record, an OSHA representative said the agency’s investigation determined that “the company was aware of the dangers, but continued to expose workers to serious and potentially fatal injuries.”
Tacoma, WA – Manke Lumber Company Inc., of Tacoma, has been fined by the Washington State Department of Labor & Industries (L&I) for 25 serious and 11 general safety and health violations, totaling $87,120.
An investigation began in December of 2014, following the fatal injury of a worker at the facility. Jeffrey Busha died on the job at Manke Lumber when his clothing was caught by a rotating shaft that pulled him into a conveyor as he was trying to loosen jammed lumber. The fatal incident prompted L&I to do a comprehensive safety and health inspection of the entire worksite.
Manke Lumber was fined $6,600 for not safeguarding exposed shafts in four locations, including the conveyor where the worker died. The exposed shafts created the potential for workers to become entangled, which can cause severe injuries, permanent disability and death.
The investigation also found a serious-repeat violation with a penalty of $8,400 for not ensuring that bench grinders were guarded to prevent severe injuries to the hand and face. The company had been previously cited for the violation in 2013.
Additionally, Manke Lumber was cited for serious violations for hazards related to “confined spaces.” Confined spaces are enclosed areas where employees are required to enter to perform maintenance and repair. Examples include hoppers, conveyors and dryers. Entering confined spaces may expose workers to the risk of suffocation, toxic atmospheres, engulfment, entrapment or other harm.
When a confined space has one or more hazardous characteristics that could harm workers, employers must control access to the area and use a permit system to prevent unauthorized entry. Anyone working in or around a permit-required confined space must be trained and there must be safety measures and rescue procedures in place.
The employer was cited for 12 violations for confined space hazards and fined $14,400.
Additional penalties totaling $57,720 were assessed for violations that included failing to guard moving parts on belt sanders, bandsaws, sprocket wheels, and pulleys; exposing workers to falls into unprotected holes and openings in the floor and open-sided elevated areas up to 10 feet; electrical hazards; failing to remove worn and damaged web slings from service; and not storing wood dust properly to prevent fire and/or explosion hazards.
Creighton, PA – Kolek Woodshop, Inc. has been cited by OSHA for ignoring electrocution hazards. The fatal electrocution of Andrew “CK” Sakala Jr. on a roofing job in September 2014 was the result of his using a non-approved aluminum ladder which made contact with a 7,200-volt power line. Kolek Woodshop sent a second employee to complete the job 72 hours later, exposing that person to the same conditions that resulted in the electrocution death of Sakala.
OSHA said it identified one willful violation because Kolek exposed the second employee to the same hazards after the fatality. The company also failed to report the fatality to OSHA. The western Pennsylvania-based roofing contractor now faces penalties of $67,900. Don’t fall into the trap and hire a ‘cheaper’ contractor to get the job done. The last thing you want are fatalities on site. You’ll find an abundant amount of roofing companies Austin who are more than likely happy to travel. You could check them out for your roofing requirements.
Christopher Robinson, director of OSHA’s Pittsburgh area office, said it was “alarming” for the second employee to be sent into the same potential danger: “The blatant disregard for worker safety demonstrated [in the Kolek case] is horrifying and completely despicable…This company’s failure to implement basic safeguards resulted in tragedy.”
Electrical accidents happen from either electrical shock or electrical arc flash explosions. We have put some videos below from cameras catching live events as well as staged demonstrations to show you how dangerous these situations are. These are why people should look to an electrical residential expert when sorting these kinds of situations out.
We also want people to understand the importance of caring for their electrical appliances correctly, and getting industrial equipment tested. There are companies all over the globe who will come out to run tests on your equipment to ensure accidents like these never happen to you. From pat testing in Bolton to pat testing in Florida, there will be a company near you to help!
WARNING: Some videos are graphic in nature and are not suitable for children.
LIVE ACCIDENTS- Electrical Shock & Electrical Explosion Videos
Describing arc flash or electrical shock in technical terms is one thing, but being able to see its impact on video is quite another. Below are some good arc flash and electrical shock video clips that are staged or educational.
American Association of Safety Councils – The American Association of Safety Councils is an international association of safety council professionals whose mission is the enhancement of safety and health.
American Industrial Hygiene Association – serving the needs of occupational and environmental health professionals practicing industrial hygiene in industry, government, labor, academic institutions, and independent organizations.
National Council for Occupational Safety and Health – The National COSH is a federation of local and statewide “COSH” groups–Committees/Coalitions on Occupational Safety and Health. COSH groups are private, non-profit coalitions of labor unions, health and technical professionals, and others interested in promoting and advocating for worker health and safety.
National Safety Council – The National Safety Council saves lives by preventing injuries and deaths at work, in homes and communities, and on the roads, through leadership, research, education, and advocacy.
An Arc Flash is an electrical explosion due to a fault condition or short circuit when either a phase to ground or phase to phase conductor is connected and current flows through the air. Arc flashes cause electrical equipment to explode, resulting in an arc-plasma fireball. Temperatures may exceed 35,000° F (the surface of the sun is 9000° F). These high temperatures cause rapid heating of surrounding air and extreme pressures, resulting in an arc blast. The arc flash/blast will likely vaporize all solid copper conductors which will expand up to 67,000 times its original volume when it is vaporized. The arc flash/blast produces fire, intense light, pressure waves and produces flying shrapnel.
When an arc flash happens, it does so without warning and is lightning quick. The result of this violent event is usually destruction of the equipment involved, fire, and severe injury or death to any nearby people.
WHAT DETERMINES THE INTENSITY OF AN ARC FLASH ?
The energy released by the arc is a function of:
The magnitude of the current
Duration of the arc
It is important to note that the clearing time (or duration of the arc) can significantly affect the intensity of an arc flash whereby lower amperage systems can become more dangerous than a higher amperage system.
I ONLY HAVE LOW VOLTAGES, SHOULD I BE CONCERNED ABOUT ARC FLASH ?
Do not be fooled by low-voltage equipment! Most arc flash accidents happen at lower voltages as a fault is created by a technician working on electrical equipment. Low voltage equipment can also have the same arc flash hazard categories as high voltage equipment. It is not uncommon to have an arc flash hazard Category 3 or Category 4 on low voltage systems due to the long cleaning time of the protective devices.
WHY DOES AN ARC FLASH HAPPEN ?
There are a variety of reasons why an Arc Flash can occur, but most of them are human error and preventable. Many arc flashes occur when maintenance workers are manipulating live electrical equipment for testing or repair and accidentally cause a fault or short circuit. Improper tools, improper electrical equipment, corrosion of electrical equipment, improper work techniques, and lack of electrical safety training are just some of the events that can lead to a devastating arc flash or arc blast.
WHAT TYPE OF INJURIES CAN HAPPEN FROM AN ARC FLASH ?
The degree of injury is directly related to the power of the arc flash, the distance the person is at the time of the arc flash, and the protective equipment worn by an individual during an arc flash. Due to the force from the explosion of energy ( the blast ) and the intense heat, burns, concussions, collapsed lungs, hearing loss, shrapnel injuries, and broken bones are common injuries. Death can and does occur from these injuries, but is mostly associated with a blast.
It is estimated that 5 to 10 arc flash and blast explosions occur in electrical equipment every day in the United States with 2,000 people each year being admitted to burning centers for severe burns.
WHAT IS MY RISK IN BEING EXPOSED TO AN ARC FLASH ?
The exposure to arc flash depends on the following:
Number of times the workers perform a task involving exposed live electrical equipment
The complexity of the task performed, need to use force, available space, safety margins, reach, etc.
Training, skills, mental and physical agility, coordination with helper
Condition of electrical equipment
The available short circuit current and the condition and rating of the overcurrent protective equipment.
WHAT ARE THE COSTS OF AN ARC FLASH ACCIDENT ?
The average cost of medical treatment for survivors of arc flash incidents is $1.5 million. The total costs have been estimated to be $12 – $15 million, which includes the following:
Lost productivity of the worker
Equipment / Facility downtime
Fines and Fees
OSHA has fined some facilities over $400K alone for not being compliant with electrical safety regulations, but the bigger cost in this is the 3rd party lawsuit if the employer did not properly identify the hazards and warn the workers about them / provide proper PPE / train the workers. Recently building and business owners have personally been found negligent in some electrical accidents.
IF I'M WEARING THE PROPER PPE, I'M PROTECTED FROM AN ARC FLASH, RIGHT?
It is important to note that wearing the proper protective equipment is designed to limit burns to second-degree burns and that PPE is the last line of defense in risk control. Those who experience an arc flash and are wearing the proper equipment can still be seriously injured or even killed from the force of the arc flash blast. An arc blast can knock people off of elevated platforms or blow doors or shrapnel across the room, to which the proper arc flash PPE provides little to no protection.
HOW DO YOU DETERMINE THE CORRECT PPE ?
In order to select the proper PPE (personal protective equipment), incident energy must be known at every point where workers are likely to perform work on electrically energized equipment. There are two methods to determine the proper PPE:
1) Perform an Incident Energy Analysis (Arc Flash Analysis) – Performing an arc flash analysis should be done by a professionally licensed electrical engineer familiar with NFPA 70E. This method takes into account the available short circuit current, fault clearing time, and other variables to determine the incident energy, which is expressed in cal/cm2. Protective clothing rated for the incident energy levels can then be chosen to match the hazard.
2) Use the Arc Flash PPE Categories Method using tables 130.7 (C)(15)(A) and (B). These tables offer a guide to picking the proper PPE Category of clothing based on voltage, task, and equipment being worked. The use of this table is predicated on first knowing the available short circuit current and fault clearing time of the equipment, AND the results of these studies must meet the parameters of the chart. Due to the level of engineering required to use the chart, most companies elect to perform the Incident Energy Analysis as it is only one more step and more accurate than using the Tables.
HOW CAN I PREVENT AN ARC FLASH FROM HAPPENING IN THE FIRST PLACE?
Unfortunately, there is no way to completely prevent an arc flash from happening in electrical distribution systems. The best one can do is to mitigate or reduce the risk.
The Risk Control Hierarchy by NIOSH systematically reduces risk to its lowest practicable level by prioritizing ways to mitigate a given risk. Higher priority and weight are given to methods that seek to control risk by proactive means as close as possible to the root cause. Meanwhile, lower priority is placed on reactive methods of controlling damage after an incident has occurred. Specifically, the Risk Control Hierarchy ranks the most effective to least effective ways to reduce risk as follows:
Elimination — remove the hazard
Only work on energized electrical equipment, when absolutely necessary. De-energizing equipment removes the arc flash hazard, although there is some risk of arc flash and blast when testing to make sure that the equipment is de-energized.
Substitution — replace higher risks with lower risks. This can be done with two methods:
Arc Flash Study with short circuit study and protective device coordination study can identify how to reduce an arc flash hazard category for some equipment.
Technologies can be implemented to reduce risks. This includes equipment such as arc limiting fuses and remote racking technologies.
Engineering Controls — reinvent ways to limit/prevent the risk
This can be done by replacing it with equipment that will lower the incident energy, including but not limited to: adjusting breaker settings and redesigning electrical distribution systems. While most of these mitigations require electrical engineering analysis, steps that don’t require engineering can be taken as well, such as implementing electrical covers with infrared inspection ports.
Awareness — raise knowledge of risks and consequences thereof
Train all workers on the hazards of arc flash Although this is #4 on the Risk Control Hierarchy, it should be the first thing done and is mandated by OSHA regulations. It is only through training that workers will understand how to eliminate, substitute, or otherwise lower the risk.
Conduct an arc flash study to properly identify the hazards, boundaries, and required PPE
Administrative Controls — create regulations, work processes, etc.
Make sure that you have a written electrical safety program AND that it is understood by everyone AND that it is enforced.
Allow only Qualified Persons wearing the proper PPE and using the correct tools to work on or around electrically energized equipment.
Implement a preventive maintenance plan for electrical systems based on NFPA 70B. A proper preventive maintenance program will help identify or fix electrical hazards before they become big problems.
PPE — use Personal Protective Equipment as the last defense.
WHAT ROLE DOES PREVENTIVE MAINTENANCE HAVE IN REDUCING THE POTENTIAL FOR AN ARC FLASH ?
Preventive maintenance should be conducted on a routine basis to ensure safe operation. A preventive maintenance program not only helps the equipment work better, but it also identifies potential hazards before they cause an accident.
As part of a preventive maintenance program, electrical equipment should be thoroughly cleaned and routine inspections should be conducted by qualified personnel who understand how to uncover loose connections, overheated terminals, discoloration of nearby insulation, and pitted contacts. A comprehensive electrical preventive maintenance plan should also include:
Using corrosion-resistant terminals and insulating exposed metal parts if possible
Sealing all open areas of equipment to ensure rodents and birds cannot enter
Verifying that all relays and breakers are set and operate properly
HOW CAN SYSTEM DESIGN IMPACT ARC FLASH HAZARDS ?
The incident energy exposure caused by an arc flash can be affected by the system configuration, system fault levels, and exposure time. System fault levels can be reduced by changing the system configuration to reduce available fault current, and by using current limiting devices such as fuses, breakers, and reactors. Using faster-acting relays and trip devices can reduce arcing time or exposure time. A protective device coordination study should also be conducted to ensure proper device settings. Instantaneous relays could also improve clearing times, limiting the arc exposure time. Fuse ratings and characteristics should also be evaluated to determine if a smaller and/or faster fuse could be used to help reduce the exposure time.
WHAT IS A QUALIFIED PERSON OR A QUALIFIED ELECTRICAL WORKER ?
OSHA states that only a “Qualified Person” is permitted to work on or near exposed energized parts and that a “Qualified Person” is “one who has received training in and has demonstrated skills and knowledge in the construction and operation of electric equipment and installations and the hazards involved.”
Establishing “Qualified Person” status is mandatory for all individuals exposed to the hazards of electrical energy who are employed at US company locations including wholly-owned facilities as well as affiliate and leased facilities where the company has responsibility for facility operations through an operating (or similar) agreement.
The term Qualified Electrical Worker should not be used unless specifically referring to those programs which use it, such as Cal/OSHA high voltage safety. This term is not interchangeable with a Qualified Person.
DO I REALLY HAVE TO DO AN ARC FLASH ANALYSIS TO BE COMPLIANT WITH OSHA ?
OSHA mandates that employers identify electrical hazards, warn employees about the hazards and provide the proper protection and training related to the hazards. Compliance with OSHA is mandatory for all US companies.
While OSHA mandates that you warn workers of the arc flash hazards, they do not mandate “how” you must do this, so in theory, companies can implement their own way to identify the hazards and protect their workers from them. In reality, however, there isn’t much choice in other ways to properly identify the flash hazards. See NFPA 130.7 Table and Full Arc Flash Protection for other options.
The definitive line in this decision becomes very clear if an accident occurs. If a person is injured or killed and the employer knew there were potential electrical hazards and either chose to do nothing about it or chose not to follow industry standards and best practices, the company is subject to a lawsuit that can exceed $10 million and individual managers can be found negligent.
WHAT REGULATIONS GOVERN ARC FLASH ANALYSIS ?
OSHA mandates that employers identify electrical hazards, warn their workers about them and provide the proper protective equipment and training related to working around the hazards. These are the only official regulations. OSHA provides the employer “what” to do, but does not define “how” to do it. The role of NFPA 70E, IEEE, and NEC is to provide guidance on “how” to properly implement the OSHA regulations.
The regulations that govern arc flash are:
OSHA Standards 29-CFR, Part 1910. Occupational Safety and Health Standards. 1910 subpart S (electrical) Standard number 1910.333 specifically addresses Standards for Work Practices and references NFPA 70E. OSHA 29CFR 1910.335 (a) (1)(i) requires the use of protective equipment from the likes of SciQuip when working where a potential electrical hazard exists and 29CFR 1910.132(d)(1) which requires the employer to assess the workplace for hazards and the need for personal protective equipment.
NFPA 70E provides guidance on implementing appropriate work practices that are required to safeguard workers from injury while working on or near exposed electrical conductors or circuit parts that could become energized. Part II 2-1.3.3 regarding Arc Flash Study / Analysis states that an ” Arc Flash Hazard Analysis shall be done before a person approaches any exposed electrical conductor or circuit part that has not been placed in an electrically safe work condition”. This Arc Flash Hazard Analysis must be done to determine the level of Personal Protection Equipment PPE that a worker must use, and the Arc Flash Boundary in inches along with the incident energy found at each location. Each electrical panel must be marked with an ANSI z535 approved Arc Flash Warning Label.
The National Fire Protection Association (NFPA) Standard 70 – “The National Electrical Code” (NEC) contains requirements for warning labels, including ANSI compliance.
The Institute of Electronics and Electrical Engineers ( IEEE ) 1584 – Provides the Guide to Performing Arc Flash Hazard Study Calculations.
WHAT DOES OSHA LOOK FOR IN ARC FLASH COMPLIANCE ?
Compliance with OSHA involves adherence to a six-point plan:
A facility must provide, and be able to demonstrate, a safety program with defined responsibilities.
Calculations for the degree of arc flash hazard.
Correct personal protective equipment (PPE) for workers
Electrical Safety Training for workers on the hazards of arc flash.
Appropriate tools for safe working.
Warning labels on equipment. Note that the labels are provided by the equipment owners, not the manufacturers.
Companies will be cited and fined for not complying with these standards.
WHAT IS AN ELECTRICALLY SAFE WORK CONDITION ?
An electrically safe work condition is defined as a state in which the conductor or circuit part to be worked on or near has been disconnected from energized parts, locked/tagged out in accordance with established standards, tested to ensure the absence of voltage, and grounded if determined necessary.
WHAT IS NFPA AND NFPA 70E ?
The National Fire Protection Association is a non-profit organization and is the world’s leading advocate of fire prevention and an authoritative source on public safety, NFPA develops, publishes, and disseminates more than 300 consensus codes and standards intended to minimize the possibility and effects of fire and other risks.
NFPA 70E is a comprehensive standard that establishes best electrical safety practices standards on how to protect electricians from electric arc flash and arc blast exposure and resulting potential injury and death. OSHA has referenced this electrical safety standard in numerous cases. Many organizations have now designed an NFPA 70E Compliance Guide to help protect their electrical personnel from the hazards associated with arc flash.
OSHA adopted regulations on safe electrical work practices in 1990 based on NFPA 70E and is proposing a revised standard that conforms to the most recent editions of NFPA 70E. Given that the NEC (National Electrical Code) and OSHA have both started referring to it in their documents, citations are now being written based on NFPA 70E.
NFPA 70e applies to employees who work on or near exposed energized electrical conductors or circuit parts. This includes electrical maintenance personnel, operators, troubleshooters, electricians, linemen, engineers, supervisors, site safety personnel or anyone exposed to energized equipment of 50 volts or more.
WHAT IS AN ARC FLASH HAZARD STUDY OR ANALYSIS ?
An Arc Flash Study or Analysis is a calculation performed by Professional Engineer to determine the incident energy found at each location which determines the various arc flash boundaries and what personal protective equipment (PPE) must be used in approaching each boundary.
As part of the study, the engineer should also provide recommendations to reduce the incident energy/arc flash hazard category, which requires a short circuit study and a protective device coordination study.
An Arc Flash Study / Analysis should only be performed by experienced and qualified electrical engineers knowledgeable in power system engineering, IEEE 1584, NFPA 70E, and arc flash studies.
CAN WE DO A STUDY / ANALYSIS OURSELVES ?
Yes, you may conduct your own arc flash study, however, there are many issues to consider.
Conducting an arc flash study/analysis is a complex process and requires engineers familiar with conducting power analysis studies and arc flash analysis in particular. Properly collecting all the data is the first phase of the project, which is difficult for anyone to do if they are not first familiar with all the potential outcomes and pitfalls of conducting an arc flash analysis. The engineer that conducts the study needs to be proficient in conducting short circuit studies, protective device coordination studies and have a strong understanding of NFPA 70E and IEEE 1584.
Beyond technical qualifications, in-house assessments are something that plant managers or engineers have little time for, often resulting in the project not getting completed or conditions of the electrical equipment changing before completion, making the results void.
The biggest reason not to do the study internally is the cost of getting it wrong. If someone is injured or killed due to an arc flash and the analysis was incorrect and done by someone who is not considered qualified to conduct the study, the liability will rest with the person or group that performed the study.
For some larger organizations that have multiple and large facilities and are willing to invest in developing a team to perform the analysis and are comfortable with the liability, conducting the studies internally can help save money. For all other organizations, conducting an arc flash analysis internally typically has little or no upside compared to any cost savings.
CAN'T WE JUST -- USE NFPA TABLE 130.7 (C) (15) (A)
NFPA Table 130.7 (C) (15)(A) identifies arc flash hazard risk categories based on tasks being performed, voltage, and the equipment on which it’s being performed on. On the surface, this table appears to be an easy and low-cost solution, however, it has many conditions and potential problems.
Using the NFPA Table is acceptable if you know your short circuit current and fault clearing time AND these results fall within the parameters of using the table. If you do not know your short circuit current and fault clearing time of each piece of the equipment or the short circuit current or clearing times exceed the parameters of using the table, then the table can not be used and an arc flash study/analysis must be conducted.
Other problems with using the NFPA 70E table include;
The NFPA 70E Table does not address all tasks. If the task one is performing is not listed on the table, the table can not be used and an arc flash analysis must be conducted.
Actual engineering studies have found that the NFPA 70E table can suggest using far more protective equipment than is actually necessary. Working in Cat 3 or Cat 4 PPE can be hot, difficult, and result in loss of dexterity and vision. If the work does not require this for safety purposes, the worker should not be exposed to this. Further, those experienced in working on electrical equipment may realize that the table recommendations are over-protective and therefore, the table gets devalued or ignored because of lack of accuracy.
Labeling: Labels are still required to warn workers of the hazards and must include specific information. Using the table alone does not satisfy the label requirements. Labels still must be put on the equipment and they must be printed using a direct thermal printer so that they stand up to extreme environments and meet NFPA requirements.
No ability to mitigate hazards. Without doing an arc flash study, there is no ability to identify and mitigate the hazards down to a lower level.
WHAT SHOULD I DO IF I HAVE TO WORK ON EQUIPMENT THAT HASN'T HAD AN ANALYSIS OR I DON'T KNOW THE PARAMETERS TO -- USE THE NFPA 70E TABLE?
using the NFPA 70E Table as a guide when an arc flash analysis has not yet been completed or when your short circuit current and fault clearing time is known is significantly better than doing nothing at all, but is not a substitute for doing an arc flash study and is only a short-term solution.
CAN'T I JUST HAVE ALL MY EMPLOYEES DRESS IN CATEGORY 4 PPE WHEN WORKING ON ENERGIZED EQUIPMENT ?
More protection is not always better and this solution does not address the six points OSHA will consider.
Working in Cat 3 or Cat 4 PPE can be hot, difficult, and result in loss of dexterity and vision. Some workers argue that while working in Cat 4 PPE provides them more protection in the event of an accident, they are more likely to make a mistake and cause an accident when wearing Cat 4 PPE. If the work does not require this for safety purposes, the worker should not be exposed to this.
WHAT IS INCIDENT ENERGY AND INCIDENT ENERGY EXPOSURE ?
This is the amount of thermal incident energy to which the worker’s face and chest could be exposed at a working distance during an electrical arc event. Incident energy is measured in joules per centimeter squared (J/cm2) or calories per centimeter squared (cal/cm2).
Holding your hand over the hottest part of the lighter flame for one second is equivalent to one calorie.
WHAT IS AN ARC FLASH BOUNDARY ?
NFPA 70e defines a “flash protection boundary within which a person could receive a second-degree burn if an electrical arc flash were to occur”. It also defines incident energy as “the amount of energy impressed on a surface, a certain distance from the source, generated during an electrical arc event.” NFPA 70e requires the calculation and creation of a “flash protection boundary”. This imaginary boundary, which surrounds the potential arc point, specifies what level of personal protective clothing and equipment must be used by qualified workers who enter within that boundary.
WHAT IS A SHORT CIRCUIT STUDY AND MUST THIS BE PERFORMED IN CONJUNCTION WITH AN ARC FLASH ?
The short-circuit study is based on a review of one-line drawings by a professional engineer. The maximum available fault current is calculated at each significant point in the system. Each interrupting protective device is then analyzed to determine whether it is appropriately designed and sized to interrupt the circuit in the event of a bolted type of short circuit. Next, the associated equipment must be reviewed to ensure that the bus bar is adequately braced to handle the available fault current. Finally, the bolted fault currents are converted into arc fault currents for additional analysis.
A short circuit study is not required to complete an arc flash study, however, short circuit information is required in order to analyze an electrical distribution system to determine if changes can be made to mitigate arc flash hazards. A minor change in an adjustable breaker may make the difference in the result of an arc flash hazard category “4” or a “2”. The availability of the short circuit information is a standard output of an arc flash study calculation, however, there is a big difference between having the information available and doing a report. Arc flash mitigation can be completed with short circuit information, but without doing a study. A study is a value-added information to help a plant run more efficiently.
Most companies that complete an arc flash study/analysis also choose to get the short circuit study as well in order to take advantage of the information at a reduced cost compared to doing just a short circuit study. Future standards for conducting an arc flash will most likely include a short circuit study in order to help standardize the expected results of an arc flash program.
WHAT IS A PROTECTIVE DEVICE COORDINATION STUDY / ANALYSIS AND MUST THIS BE PERFORMED IN CONJUNCTION WITH AN ARC FLASH STUDY ?
A coordination analysis is the examination of the electrical system and available documentation with the goal of ensuring that over-current protection devices are properly designed and coordinated. Over-current protective devices are rated, selected, and adjusted so only the fault current-carrying device nearest the fault opens to isolate a faulted circuit from the system. This permits the rest of the system to remain in operation, providing maximum service continuity. The study consists of time-current coordination curves that illustrate coordination among the devices shown on the one-line diagram. Note that protective devices are set or adjusted so that pickup currents and operating times are short but sufficient to override system transient overloads such as inrush currents experienced when energizing transformers or starting motors.
A protective device coordination study is not required as part of an arc flash study, however, doing this analysis one can determine if minor revisions in breaker settings or equipment can lead to major reductions of arc flash hazards. No arc flash analysis should be completed without first doing a protective device coordination analysis in order to save money and to remove potential hazards.
WHAT ARE ARC FLASH HAZARD CATEGORIES ?
The hazard/risk category is specified as a number representing the level of danger, which depends upon the incident energy. The category ratings range from 0 to 4 where category 0 represents little or no risk, and category 4 signifies the greatest risk. Above category 4 (>40 calories/cm2) all equipment is considered too dangerous to work on energized because of the tremendous pressure blast.
WHAT IS AN ARC FLASH LABEL ?
The NEC® and NFPA 70E require the labeling of equipment to warn of potential arc flash hazards. Each panel must be marked with an ANSI-approved Arc Flash Warning Label to warn and instruct workers of the arc flash hazard, voltage, arc flash boundary, and required PPE (Personal Protective Equipment). Subject to the requirements of the facility and arc flash analysis, labels are attached for each analyzed point of concern.