Reducing Electrical Hazards
When safety becomes one of the design criteria for a project, it's a much more economical approach for that customer or company.
- By Jerry Laws
- Jun 01, 2016
Portable generators, power lines, and extension cords are all covered in OSHA's fact sheets about electrical safety for workers. They’re all intended to help workers recognize common hazards and take sensible precautions in order to work safely.
Shock and electrocution hazards are associated with the use of portable generators, as is a carbon monoxide asphyxiation hazard if a generator is being operated indoors or is not adequately ventilated. The hazard associated with overhead power lines to workers on roofs or lifts is failing to maintain a safe distance from the line, and more than 90 percent of the accidental contacts are with overhead electrical distribution lines. But underground lines pose an equivalent hazard; operators of large excavation equipment always should be aware of the location of both underground and overhead power lines before beginning an excavation. The U.S. Bureau of Labor Statistics estimates there were a total of 392,570 workers employed in U.S. electric power, generation, and transmission as of May 2015.
Tony Parsons, a technical consultant in power system engineering for Schneider Electric's Field Services unit, helps customers who are looking to upgrade or improve the performance of their electric power distribution systems, whether the equipment is malfunctioning or is near the end of its useful life. A professional engineer located in Austin, Texas, he works with customers on their existing electrical infrastructure and also for upgrades and modernization. And sometimes he and his colleagues are called in by a customer after a serious incident has occurred, he said during an April 22 interview.
"Unfortunately, there have been some cases where we're brought in to do an assessment following a serious injury or fatality. Obviously, that's the last thing we want to see happen. We appreciate the business, but we'd much rather have it because a customer or a site was really educating themselves on the risk they may face and trying to do something about it before these things happen," he said, adding that he'd heard a conference presenter say that most of the electrical accidents that occur—shock, arc flash, etc.—are in the workers' initial years in the industry or when the workers are in the final years of their careers, before they planned to retire. So the latter may be injured because they "know too much," as Parsons put it, and they start to get complacent: "Just because you've gone 20 years and never had an accident doesn't mean that it won't happen in year 21."
Equipment upgrades are done to for a variety of reasons as companies seek greater efficiency. "It depends on how forward-looking the customer is, how they look at their systems," he said. Some companies will run their equipment to failure and then replace something after it fails, while others try to anticipate failures and update before a piece of equipment goes critical, he explained.
Evaluating Arc Flash Hazards
Parsons' end of things is the engineering analysis. He said a recent project was conducting an arc flash hazard analysis for a large power generating station. The Schneider Electric team evaluated the anticipated arc flash energy levels, which Parsons pointed out have been a primary focus of electrical safety guidelines and standards in recent years. Their study showed there were several locations in the generating station where energy levels were excessive for employees who were working around the equipment, he said, and the team then looked for ways to bring those levels down because the customer didn’t want to have its employees exposed to them.
They work with the customers to understand what they want and survey their equipment. In this recent case, the solution was upgrading some electrical relay equipment and replacing some older circuit breakers without having to scrap much of their electrical infrastructure, he said.
This project served as a reminder that PPE is not the sole answer to the arc flash challenge. Engineering controls—equipment changes and mitigating the hazard—come first in the hierarchy of controls and are considered the most effective type of controls. Reflecting this, Parsons said that he's seen "at least the beginnings" in the electrical industry as a whole of this mitigation approach, after conducting arc flash analyses for his company’s customers for at least a decade. Where customers initially wanted to ensure their employees were wearing suits and PPE that would protect them from the expected hazardous energy levels, some customers realized their workers might have to wear an excessively heavy and bulky suit, he said, and then "they want to go one step further and see how they can reduce the hazard."
He noted that industry consensus standards often don't use this approach, however. While everyone is familiar with the NFPA 70E standard, it is a work practice standard that does not require anyone to go out and proactively reduce a hazard, Parsons explained: "You deal with what's there." And NFPA 70, the National Electrical Code®, the standard followed in every U.S. state for safe electrical design and installation, doesn't have much in the way of hazard mitigation, either, he added.
In the same vein, Parsons said he favors the concept of safety by design—an approach favored by OSHA and by NIOSH in its Prevention through Design National Initiative.
"The basic idea is that, too many times in the past, safety's kind of been an afterthought," he said. "Everybody knows that, yes, we know we have to work safely, we have to wear protective equipment, but if you think about how you actually design your equipment," companies may not be considering safety at the design phase of their projects as much as they should, he said; similarly, engineers who design electrical power systems may be designing them for efficiency and for reliability, but they may not be considering the safety side at that stage. Yet when safety becomes one of the design criteria for a project, it's a much more economical approach for that customer or company.
Technology can be a key advantage for older industrial plants, some of which are still using equipment that has been operating for 50 to 60 years. Some do a very good job of maintenance, but some plants do not, Parsons said. So the Field Services personnel can help with upgrading circuit breakers and relays for better performance and also to take advantage of monitoring technologies that can be added during the modernization process. With thermal sensors in place, plant operators can get automatic 24/7 readings on equipment performance rather than taking readings at set maintenance intervals—readings that might require a hazardous worker exposure. So this plant is getting safety intelligence built into its switchgear.
"It's not widespread, but if you go to electrical conferences, I've noticed you see a lot more folks talking about how these systems are implemented. It is a thing that's out there, again, not a widespread adoption of technology, but I think you're going to see [greater use]," he said.
And the more challenging business cycle many companies are currently experiencing won't interfere with this trend, he said: Companies that are committed to doing things right will do so even in down business cycles, rather than abandoning these projects during downturns.
OSHA on April 1, 2016, announced a continued partnership with the National Electrical Contractors Association Central Ohio Chapter and the International Brotherhood of Electrical Workers' Local Unions 683 and 1105 to improve electrical workers' safety.
The partnership will emphasize electrical safe work practices, training, enforcement policies, and sharing of best practices among contractors. According to the agency, contractors will focus on electrical safety, falls, struck-by and caught-between hazards, and adopting the use of an industry standard checklist. Participating employers pledge to maintain Days Away, Restricted or Transfer and the Total Cases Incident Rate injury and illness rates below the Bureau of Labor Statistics’ data for electrical contractors.
"We're excited about continuing this partnership with the NECA/IBEW after over ten years of success, because we know efforts like these improve workplace safety by fostering education, training, teamwork, and prevention on the job site," said Deborah Zubaty, OSHA's area director in Columbus.
This article originally appeared in the June 2016 issue of Occupational Health & Safety.