Dielectrics are critically important to utility workers. These materials are necessary for more complete arc flash protection because they transmit electric force without conductivity — meaning they insulate utility workers from extreme electric shock. Whether out in the field or in a substation, dielectric clothing and equipment are common in areas that present electric shock dangers. But how much do you really know about dielectrics? Is it enough to keep your workers safe?
According to Roderick Metcalf, a lineman with Tuscumbia Utilities, dielectric materials are too often taken for granted. He offers the following tips in order to stay safe.
1. Clean Dielectrics Often
Dirty dielectric clothing and tools are dangerous because dirt, dust and moisture are conductive materials. When debris or moisture collects on dielectric tools such as fiberglass hot sticks or tree trimmers, the tool’s ability to keep workers safe is diminished.
“It’s important to have a place to store dielectrics both during use in the field and when not in use so that they don’t collect dirt or other conductive materials,” Metcalf cautions. Using special cloths and cleaning fluid are essential to wipe down the tools between every use, as are using safety practices like keeping dielectric fiberglass tools off the ground, where they can collect dirt. Over time, dielectric fiberglass tools may need to be waxed or even refinished to retain their dielectric properties.
2. Take Extra Precautions on Rainy Days
“Transmission linemen who work with high voltages every single day are used to wearing dielectric boots. But, for other linemen, dielectric boots aren’t as commonly used. This presents a huge risk on rainy or stormy days, when the linemen’s feet are wet and the rest of their bodies are soaked to the bone,” says Metcalf.
His tip is to be sure that dielectric boots are maintained regularly and inspected well before each use, even if they haven’t been used since the last time they were inspected.
3. Air Test Gloves Regularly
While arc flash-rated gloves should be manually inspected for wear and tear between each use, manual inspection is not enough to keep the gloves dielectric in the long run. “Even a pinhole in a glove can create electric shock,” Metcalf says.
These hazards cannot be detected by the naked eye, which is why air testing and electrical testing are critical. OSHA recommends gloves be visually inspected and air tested for any possible defects (for example, cuts, holes, tears, embedded objects, changes in texture) before each use and whenever there is a reason to believe they may have been damaged. In addition, gloves must be electrically tested at regular intervals of not more than six months.1
4. Use Dielectric Sprays and Lubricants
Metcalf points out that there are an increasing amount of dielectric sprays and lubricants on the market, which presents a great opportunity for increased safety. “We use dielectric wasp sprays and even dielectric lubricants on the hydraulics and nearly every nut and bolt within our bucket trucks,” he says. “You cannot be too safe when it comes to insulating from electrical hazards."