August 11, 2003
Once Burned, Twice Shy . . . If You’re Lucky.
Keynote Address Presented by
John W. Estey,
President & CEO, S&C Electric Company,
at the 10th Annual IEEE IAS Electrical Safety Workshop,
Houston, Texas, February 5, 2003.
Thank you and good afternoon. I congratulate Lanny Floyd and the IEEE Industry Applications Society on holding this 10th annual workshop. Electrical safety is a very important topic. Every injury is important, as every injury is personal and can interrupt careers or even end lives. Each of you deserves congratulations and thanks for being here. Your presence puts you in the top percentile of facilities folks in terms of your knowledge and your interest in electrical safety. You are truly following the advice of Indira Gandhi, who said, “There are two kinds of people — those who do the work and those who take the credit. Try to be in the first group, there’s less competition there.”
When preparing my remarks for today, I was pretty intimidated by the tremendous knowledge of this group. Since my experience is mostly in medium and high voltage and since most facilities folks are more knowledgeable about low voltage, I decided it would be most appropriate if I spent my time today on medium voltage. Because medium voltage is so potent, one mistake could easily be your last so I decided to title my talk “Once Burned, Twice Shy . . . If You’re Lucky.”
The Hierarchy of Safety
In considering almost any hazardous operation, including medium-voltage electricity, the best place to start is with the hierarchy of safety. The first step in this hierarchy is Engineering Controls, which means trying to do everything practical from an engineering perspective to reduce hazards. The second step involves Administrative and Work Practice Controls, such as the use of warning labels, performance of regular inspections, and documenting the proper steps to take in carrying out each task. The third step is to ensure that operating personnel use appropriate Personal Protective Equipment, or PPE, such as electrically rated footwear, fire-retardant clothing, arc-flash-protection suits, and so on.
Since everyone here has systems and equipment already installed and operating — and since it’s not practical to re-engineer or replace all of that equipment any time soon — it makes sense to begin our discussion of medium-voltage safety in the middle of the hierarchy with Administrative and Work Practice Controls. We will then go to the beginning of the hierarchy, Engineering Controls, which is an area where this group can really make a big difference for the future. I won’t cover the third step in the hierarchy, PPE, since that is so well covered in many of the other talks at this meeting.
Administrative and Work Practice Controls
In discussing Administrative and Work Practice Controls, I will assume that everyone here is familiar with NFPA 70E. This standard, which was written by industry practitioners, forms the basis of OSHA Subpart “S,” and places significant responsibilities on the employer for electrical safety, including having a complete electrical safety program. It provides a great place to start in developing your Administrative and Work Practice Controls.
These controls need to deal with the safety of the authorized and the unauthorized, the qualified and the unqualified. As an example of the risks you need to deal with, consider the outdoor medium-voltage switchgear that was making an unusual, loud buzzing sound. A large crowd of unauthorized and unqualified onlookers gathered in front of the equipment, all curious to know what was causing the noise. Imagine the consequences if that gear had suddenly developed an internal arc that blew the doors open, throwing parts and hot gases at the crowd. Or, how about the poor, unqualified maintenance man who was sent in to clean up an electrical room? No one thought to warn him that those porcelain things on top of the medium-voltage switchgear were energized, as were the cables attached to them. Fastidious cleaner that he was, he decided to clean those roof bushings using a vacuum cleaner — with a metal nozzle. And how about the authorized but unqualified maintenance people sent to drill some holes through the wall of an enclosure containing medium-voltage equipment. They were more than surprised when the drill bit broke through the wall, penetrated the insulation on a medium-voltage cable, and vaporized in the ensuring arc. Good thing the enclosure was well grounded!
Even the authorized and qualified are in danger if they take their successful safety records for granted. Over-confidence can and does kill! Consider the utility worker in the desert of California who reached into switchgear to pull out a bracket lying on the floor, saying “not to worry . . . it’s so dry here, you can easily get close to energized parts without a problem.” In another incident, a utility worker removed the cover from one of two adjacent medium-voltage cabinets and verified that it bore the number of the de-energized circuit on which he was to work. Unfortunately, he did not realize the removable covers had been switched so the cabinet from which he just removed the cover was actually the one that was energized. He went to work without testing or grounding and was killed instantly.
Good administrative systems and work practices can prevent incidents like these. To successfully develop such practices, it is essential that you be familiar with medium-voltage systems and equipment and the hazards involved with them. Unfortunately, very few facilities folks have had the opportunity to learn in depth about medium voltage and its risks. For instance, I know of a two-million sq. ft. industrial plant in Illinois that has just one person knowledgeable about the equipment and hazards involved with their extensive medium-voltage system. The knowledge gap is even more chronic in companies where top management has made the mistake of essentially eliminating in-house engineering staffs, thereby removing the on-site expertise that could help prevent injuries and save lives.
Medium-Voltage Hazards Are Different
Many of the hazards at medium voltage are different from those at low voltage and, fortunately, work practices can be a huge help in dealing with a number of them. For instance, you must bleed off any static or trapped charge or it will inflict some real harm. You need to be concerned about step potential and equipotential grounding. And, you need to guard against unrecognized sources of medium voltage such as PTs that are backfed from still-energized low-voltage sources. These hazards are why work practices almost always require isolating and grounding medium-voltage circuits before work is done, even though grounding is used much less frequently on low-voltage equipment. In carrying out this work, it is crucial that the grounding provisions be rated for the system duty, which poses an interesting problem because most grounding equipment isn’t rated. When S&C’s Field Service people visit sites of power users, they are amazed at what people will use for grounding equipment — everything from automotive jumper cables to bundles of #10 wire that couldn’t carry the fault current for even a few cycles.
And, grounding equipment must be used correctly. Consider the plight of the plant maintenance worker asked to work on gear that reportedly has been isolated and grounded. How can that worker be assured that the grounding sets are up to the rating of the system and, even more importantly, that the sets have been installed properly? You’d better be able to answer that question in advance of any work, as you’ll certainly be asked to explain it if an accident occurs. Good safety work practices are the cheapest insurance you can have and their preventive powers make them worth the work compared to unpleasant inquires after an accident.
When it comes to operating or maintaining medium-voltage systems, one major problem is that the equipment only needs to be worked on or operated infrequently so it is difficult to maintain currency in the techniques and procedures. To overcome the lack of on-site experience in the operation of this gear, many plants use outside contractors for medium-voltage work. This is certainly a good practice, but it should be understood there’s a wide range of experience among contractors claiming to know how to do medium-voltage work. You should scrupulously examine the references and qualifications of any such contractor because hiring a contractor does not relieve you of your responsibility to your employees. NFPA 70E keeps you on the hook, as does common sense.
Both 70E and common sense also require you to work with your people on each and every job. This is even more important than on low-voltage systems because medium-voltage equipment is operated so infrequently. For every task, no matter how mundane, the proper procedures need to be reviewed in depth with the people involved. It is also crucial to ensure that the people are qualified for the task at hand and that they understand the equipment layout and operating features, how to read the one-lines, how to verify open gaps for the specific circuits they’ll be working on, how to avoid backfeed, static charge, and so on. Your people should always question what they see, what they think, and what they’re doing. As Mark Beutnagel of Texas Instruments said, ’The danger is not what you know, but what you think you know that ain’t so.” As a private pilot, I am regularly reminded that there are bold pilots and there are old pilots but there are no old, bold pilots.
Alliances with Key Suppliers
One of the best ways to help understand the hazards involved with medium-voltage systems and equipment—and to develop the work practices to deal with them — is to develop alliances with the engineering staffs of your key suppliers of such equipment. You will find them knowledgeable and quite happy to share their expertise with you. The knowledge you gain by working with your suppliers in these alliances will not only help you in your medium-voltage work but may help at low voltage too, as many of the safe work practices emerging for low-voltage equipment largely came from experience gained working at medium voltage. This includes arc-flash hazards, safe approach distances, and the use of appropriate PPE for flash-hazard protection. The Administrative and Work Practice Controls that result from close alliances with your key suppliers can be of significant value in helping your workers avoid the hazards involved in operating medium-voltage systems.
Now, even with all that has been done in terms of work practices and all the requirements of OSHA Subpart “S” and NFPA 70E, there are still too many injuries and deaths associated with operating electrical equipment. You might wonder why. The main answer seems to be that, even with good work practices, people still make mistakes. So we need to continually seek out new and innovative ways to protect against these mistakes. That brings us to the first step of the safety hierarchy, Engineering Controls — the step in which you use engineering to do everything practical to reduce hazards. You can do this through the electrical systems you design and the engineering decisions you make in purchasing equipment. Electrical equipment has, from its very beginning, continued to evolve to be safer and more “idiot-resistant.” As a result, there are a great many Engineering Controls you can employ.
As with the design of Administrative and Work Practices, the development of Engineering Controls requires you to have a thorough knowledge of the hazards involved. Again, forming strong alliances with your key suppliers of medium-voltage equipment can help you learn about those hazards and how the equipment can be designed to minimize them. Manufacturers will be happy to work with you because they are hungry for design input from knowledgeable users. This is a classic win-win situation as you and your co-workers will benefit from safer equipment designed to suit your systems, and the manufacturers will benefit from the knowledge of power users like yourselves. Intel, which has an outstanding OSHA incident rate of just .19, holds a design conference with its key suppliers every year at which they talk about safety, quality, and cost.
Engineering Controls Help
Fortunately, many medium-voltage hazards can be dealt with through Engineering Controls. At medium voltage, you don’t need to actually touch the conductors to be shocked as was so tragically learned by the utility lineman in the desert, who thought he could get close without harm because it was so dry there. To reduce such mistakes, gear can be designed to minimize exposure and access to medium voltage. And, medium-voltage arcs inside a piece of equipment are much more violent and difficult to control than most facilities folks can imagine. To understand the phenomenon, let’s look at a video of the damage wrought by an arc inside a relatively typical piece of medium-voltage switchgear. The system in this video is rated 15 kV and the fault current is 40,000 amperes. You will see a rack in front of the gear holding cotton patches that simulate the clothing worn by an operator. The operation will be shown at normal speed and then in slow motion.
As you could see, the door came open with such force, it actually bent around the frame in front of the gear and the hot gases blew right through the opening in the front. Most facilities engineers are astounded when they see the extraordinary violence of an open arc like this inside medium-voltage equipment. Fortunately, you can use newer technologies as part of your Engineering Controls to deal with internal arcs. As many of you know, there’s a new class of switchgear called “arc-resistant” that is designed to handle this kind of internal fault. I confess I have never liked the term “arc-resistant” because most uninitiated people conclude that it is resistant to the initiation of arcs. Unfortunately, that is not true. It’s sort of like the term “life insurance” — if only it did what its name implies!
Arc-Resistant—A New Class of Switchgear
Gear called “arc-resistant” is actually designed so that the doors stay closed and the hot gases are vented away when arcs occur inside the gear with the doors closed. There are a couple of standards that define how to test the gear to demonstrate these capabilities. Among other things, to pass these tests, arc-resistant gear needs doors that remain closed and do not let any parts fly outside of the equipment when internal arcs occur. Further, any gases that do escape must not ignite cotton patches placed about 4 inches away from the gear around any openings up to about 6.6 feet above the ground. By meeting these standards, the gear should isolate your people from exposure to the arc. Such gear can be designed in a myriad of ways, but most manufacturers vent the hot gases up and away from the operator. Let’s look at a video of a successful operation of arc-resistant switchgear that uses this technique. You will see that the internal arc is still violent and extremely difficult to handle. But, the gear keeps the door closed and the cotton patches are not burned. In this video, the gases are vented upward but, for purposes of the test, are not ducted away — as they would be in an actual installation. As a result, more smoke and arcing is visible than would normally be the case.
As another example of how medium-voltage switchgear can be built safer, technologies exist today that can completely isolate operators from exposure to medium voltage during switching, fault interruption, voltage testing, grounding, phasing, and most other normal operations — while still providing a full view of the open gaps. Such gear can also be made “arc-resistant” and can further reduce worker exposure through automation for remote control.
Unfortunately, facilities folks have been exceedingly slow in adopting arc-resistant gear and gear using these new technologies that can help enhance worker safety. Why, you might ask, has adoption been so slow? Well, at the risk of proving that Ben Franklin was right when he said he “never knew a man who was good at making excuses who was good at anything else,” let me give you some explanations people have offered. One often-cited reason for this slow adoption is that people don’t have time to work on anything new. Indeed, with all the downsizing that’s gone on around the industry the last several years, many feel a little like Malcolm Forbes who said, “Unless you’re serving time, there’s never enough of it.” However, when dealing with the safety and lives of our people, the time pressures on us can never be an excuse for failing to keep up with safety technology.
The Risks Are Not Well Known
In many cases, adoption is slow because the risks are neither well known nor well understood. The surprise that engineers typically express when they see the incredible power of an arc inside equipment is a perfect example. It is imperative that you become familiar with the hazards to which your workers can be exposed if you plan to protect them properly.
Some say they don’t need these kinds of enhancements because they haven’t had workers hurt in that way. I sincerely hope these folks don’t drive around without wearing seatbelts just because they’ve not yet been in a head-on collision. In industry, we shouldn’t need to experience a problem before we take steps to prevent it, because doing so means we’ll be too late to do the injured or deceased any good. It is a sad commentary on business today that it often takes ten signatures to buy something but only one to fix it. And, when accidents occur because preventive measures have been slow to be adopted, we will prove Robert Half was correct when he said, “The search for someone to blame will always be successful.”
People also say they are hesitant to adopt these safety measures because of the cost. For instance, arc-resistant gear typically costs about 10 to 20% more than regular gear. I’ve often wondered how many cars would have airbags if this were an extra-cost option, and how many people would be injured or killed in cars for which the buyer paid a little less.
You Need to Judge the Degree of Risk
As in all things, we engineers are expected to assess the degree of risk posed by various hazards and the costs involved in avoiding them. I like the ancient Roman tradition that made it clear to engineers they must accept responsibility for their work. When the scaffolding was removed from a completed Roman arch, the law read that the engineer who built the arch had to stand beneath it. If the arch came crashing down, he’d be the first to know. As a result, the Roman engineer knew that the quality of his work would have a direct, personal impact on his life. That’s why it’s not surprising to find so many Roman arches have survived through the ages. We also live with the systems we design and the equipment we purchase.
In exercising your judgment, you wouldn’t, for instance, buy arc-resistant gear if your system could muster only a few thousand amps of medium-voltage fault current. However, it would be a real shame for those with high available fault currents to not buy such gear because they have not yet experienced an internal arcing event. Or because the equipment costs a little more. Or, even worse, because they lack a full understanding of the hazard posed to their people by internal arcs. The pressure on us to make these decisions wisely is gaining importance as OSHA’s Safety Related Work Practices and NFPA 70E require employers to protect employees from more and more hazards.
This Workshop Plays Important Role
This workshop can play an important role in helping people decide what the real hazards are, and which ones have high-enough probability to warrant working on ways to reduce them. By using this venue to share experiences, the entire group will be better off, as will the employees who work in your companies. Once you’ve determined the hazards you need to engineer away, you will need to convince your company leadership that the efforts to eliminate these hazards are worth the time and money. If, as I suggested earlier, you form alliances with your key suppliers to help design and engineer safer equipment and practices suited to your system, those suppliers should be able to help you in convincing your management of the value of your selected approach. Suppliers can use their knowledge of the hazards and the practices used by others to help make a persuasive case for what you have decided needs to be done. For instance, the headquarters of a large industrial firm decided to standardize on arc-resistant equipment. But every time a facility needed equipment, the local plant manager balked at the extra cost. Even though arc-resistant gear was made company policy, the local facilities engineers regularly had to ask their supplier to help convince the plant manager this equipment was a prudent safety investment.
We, as engineers, are the ones most able and most responsible for sizing up the risks and the costs, and then developing workable solutions. By working hand-in-hand with your key suppliers to understand the hazards, Engineering Controls can be used to minimize many of them, and Administrative Systems and Work Practice Controls can help your workers avoid the hazards that are left. Through these steps, you can make a significant contribution to the lives and safety of your coworkers. And, by working with your key suppliers in this way, you’ll be able to stay up to date on the latest technologies for improving the safety of the facilities for which you are responsible.
IEEE Standards
One other important contribution you can make — not just to the safety of your coworkers but to people throughout the industry — is to work on writing and updating industry standards. The IEEE Power Engineering Society has the task of writing the standards for many components you use, including switchgear, transformers, surge arresters, power system relays, and so on. Unfortunately, PES is not too well populated with practicing engineers from industrial, commercial, institutional, and government facilities. As a result, these industry standards often suffer from insufficient participation by power users like you. This work can certainly benefit from your help and I can assure you that it would be thoroughly appreciated.
As we all continue to work on safety, sometimes the greatest danger is not that our aim is too high and we miss it . . . but rather that our aim is too low and we reach it. By attending this workshop, you’ve shown that you are not aiming too low. I hope that my remarks have helped in some way to advance one of this conference’s missions, which is to stimulate innovation in overcoming barriers. And, I hope that we can all help achieve the second conference mission, which is to accelerate the application of breakthrough improvements in human factors, technology, and managing systems that reduce the risk of electrical injuries. Thank you very much for your kind attention.