Editor's Note: Electrical Contractor would like to draw attention the risk of working on energized equipment. It's never safe to work on live equipment. The equipment and tools in this article will minimize risk when working on energized equipment is justified and necessary. Consult applicable codes and standards. In every case, Electrical Contractor recommends equipment be de-energized unless doing so would produce greater risk or is just not possible. For those cases, Electrical Contractor recommends the following tools and equipment be readily available for use.
Electricians, owners and managers of electrical contracting firms understand the dangers of working with electricity and that there are personal protective clothing and equipment and insulated tools designed specifically to protect against electrical hazards. Protective clothing, boots, gloves and equipment shield personnel from arc flashes and other risks, and insulated tools are available for working on or near energized circuits.
The Occupational Safety and Health Administration (OSHA) requires the use of personal protective equipment (PPE) to reduce employee exposure to hazards when engineering and administrative controls are not feasible or effective in reducing these exposures to acceptable levels. It is the employers’ responsibility to determine whether PPE should be used to protect their workers.
Westex, Workrite and Salisbury are among companies offering PPE for electrical work. Insulated versions of most basic hand tools electricians use are available from specialist suppliers Cementex Products, Certified Insulated Products and other tool companies, including Channellock, Ideal Industries and Klein.
Electricians use PPE to guard against both shock and electric arc hazards; the primary guideline is NFPA 70E, said Scott Margolin, international technical director for PPE manufacturer Westex (www.westex.com).
“OSHA tells us what we shall do, but not how to do it,” he said. “Therefore, it is very difficult to definitively note which standards PPE must meet. However, OSHA has clearly established over time that they rely on industry consensus standards, of which 70E is by far the most relevant and heavily used for electricians outside the utility T&D environment. OSHA has issued a letter that states, while they do not, per se, enforce NFPA 70E, compliance with 70E means compliance with OSHA.”
NFPA 70E, Margolin said, requires various levels of PPE depending on energy level of the system being worked on, but PPE generally includes rubber gloves, leather keepers, a hard hat, a face shield, and flame-resistant garments that cover the arms, legs and torso.
“When properly used and maintained,” he said, “these products will protect the electrician from shock/electrocution and from high percentage second-degree or worse body-burn injury. The significant majority of severe injuries and fatalities in electric arc flashes are not caused by the arc itself; rather, they are a result of flammable clothing igniting and continuing to burn long after the flash is over. This can dramatically increase both the extent and severity of burns.
“An electrician wearing all PPE-prescribed by NFPA 70E would be expected to receive very little or no second- or third-degree burns should there be an arc flash,” Margolin said.
Workrite Uniform Co. (www.workrite.com) Technical Manager Mark Saner said, for arc flash hazards, electricians must wear clothing arc-rated to a level equal to or greater than the arc flash exposure potential.
“NFPA 70E provides information on how to determine the arc flash exposure potential and specifies the use of clothing that meets the ASTM F1506 standard. Other protective equipment for head, face and hand protection also is required in different exposure situations.
“Arc-rated clothing will have either an arc thermal performance value (ATPV) or energy break-open threshold (EBT) assigned. Both are arc ratings and are shown as calories per square centimeter. The arc rating of a garment will vary depending on the fabric type, weight, weave, etc,” he said.
Saner said new fabrics made of various fiber blends, including modacrylic/aramid, modacrylic/lyocell, modacrylic/cotton, aramid blends, and others have been introduced in recent years. Garments made from these fabrics provide a variety of options of weights, colors and protection levels.
According to Westex’s Margolin, there have been major advances in comfort of flame-resistant protective apparel recently.
“The most popular brands in the 70E market are cotton-rich blends, which is what most of us choose to wear when off the clock,” he said. “These fabrics are now available in many of the same styles and weights as street clothing and even in knit T-shirt (albeit long sleeve) form. In the past, people who wanted to avoid flame-resistant clothing often ‘upgraded’ to 100 percent cotton in the erroneous belief it is safer than poly/cotton blends because it doesn’t melt. This is arguably the most dangerous myth in the flame-resistant world. Cotton is not an upgrade. It is every bit as dangerous in an arc flash.
“There are four major problems with cotton: it ignites just as easily as poly/cotton; it burns hotter, meaning more skin damage more quickly; it is much harder to extinguish; and it is usually heavier, meaning more fuel, a longer fire, and thus, worse burn. For working ‘hot,’ flame-resistant garments are a must. Choose fabrics that are flame-resistant for the life of the garment, guaranteed, market-proven over time, and arc-rated to or above the hazards faced.”
There are insulated versions of most basic hand tools used by electricians. Be aware that cushioned grips popular on many of today’s hand tools might appear to provide insulation, but actually do not.
NFPA 70E guidelines for working around exposed, energized circuits apply to insulated tools as well as protective clothing and equipment, and complying with its provisions will result in compliance with OSHA regulations.
Genuine insulated tools are identified by the international 1,000-volt (V) rating symbol, certifying they have been individually subjected to 10,000V and passed other tests stipulated in ASTM standard F1505. True insulated tools also comply with the International Electromechanical Commission (IEC) 60900 standard.
Ben Bird, chief operating officer of Certified Insulated Products (www.insulatedtools.com), said insulated tools made of composite materials are a significant advancement because they eliminate insulating coatings that can be nicked or torn through normal use. They are lighter in weight and slimmer than other tools, allowing access to very tight areas. For example, screwdrivers and nut drivers are made from braided, military-grade fiberglass composite over a tough, polymer core.
Jeffrey Russo, vice president and chief operations officer for Cementex Products (www.cementexusa.com), said that there hasn’t been much change in the array of available insulated tools but that the safety insulted tools provide has increased demand for them.
“Insulated tools are required on just about every job site where electrical workers will be modifying, maintaining or flat out overhauling switchgear, motor starters or battery banks,” he said. “It’s all about having the right tool to not only do the job, but do the job safely.”
Pliers, screwdrivers and nut drivers lead the way, Russo said.
“They are the basic and essential tools for almost any electrical worker. Insulated tools allow electrical workers to work within the known energized electrical components and know they are working with tools specifically designed for the energized work they are doing.
“More and more commonly used are T-handles, ratchets, and torque and socket wrenches, available in different drive sizes, lengths and functions,” he said. “Wrench styles vary, including fully insulated and bare-head adjustable, box, open, ratcheting box and brandnew ratcheting open end, all of which are single-end use tools. T-handles are available in different lengths, which allow workers to be a greater distance from potential arc flash.”
Russo said that specialty tools are becoming increasingly common, including flashlights, inspection mirrors and magnetic-retrieval tools.
“Methods used to provide insulation for insulated tools is a trade secret,” Russo said. “The insulation formula is unique to every company that applies a coating on tools. The process is generally the same, but the exact process is a closely held and detailed secret.”
Greenlee (www.greenlee.com) offers a broad line of tools for electricians, including a selection of insulated tools. For Greenlee, screwdrivers are the No. 1 insulated tool, followed by side-cutting pliers, said Michael Stephens, senior product manager. Other popular insulated tool products include wire cutters, long-nose pliers and nut-drivers.
A recent change in insulated tools, Stephens said, is greater use of injection-molding processes—instead of dipped or heat-shrink methods. Injection molding allows for use of a larger variety of materials, including softer, more comfortable handles and better ergonomic features. It also enables use of different color combinations.
Stephens said the basic principle of achieving insulation is simple.
“Ensure there is no conductive path from the isolated contact point or ‘business end’ of the tool and the tool user,” he said. “This can be accomplished by making the entire tool out of nonconductive material, such as ceramics, reinforced plastics or other composites, or most commonly, [by encapsulating] the entire tool, with the exception of its business end with nonconductive material such as PVC-type material, polypropylene, etc.”
To maintain their insulating properties, insulated tools require careful use and care. They should be carried and stored in a manner that will minimize damage to insulation. Contaminants should be removed from tools immediately without using harsh detergents, which can prematurely age plastic coatings. After cleaning and thorough drying, tools should be stored in an area away from heat sources.
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at email@example.com.