Q: With all the talk about grounding, cover-up, EPZ and minimum approach distances, we have been debating the best practice for setting steel poles in energized 138 kV. A big question is, what class gloves should ground personnel wear while handling the pole? How can Class 3 or 4 gloves protect against 138 kV?
A: The short answer is that a Class 4 glove won’t protect against 138 kV. However, if you do it right, there is a very good chance you won’t be exposed to 138 kV even if you do get the pole in the 138. Here is how and why. At transmission voltages, we rely on planning, equipment setup, and precise/predictable control of the equipment and airspace to prevent contacts. We then take additional equipotential bonding actions to protect against a worst-case scenario like loss of control and pole contact with a circuit.
Here are some recommendations for those additional actions. Grade the work area. Grading the area flat around the pole hole gives the crew space for equipotential mats or grids. In best-case planning, it is ideal to stand the pole up with little hands-on contact until you get to the grabbers. If you are using portable mats, the prime location is at the stand-up/grabber location. During handling, the crew members on the pole butt will be in an EPZ. The pole then gets swung to the hole without crew contact. At the hole, mats are used to line the hole for crew who will handle the pole setting. Many crews are now using cattle panels as grids to create equipotential mats in the pole-setting areas. The panels are available at feed stores, constructed of welded #4 steel wire and bonded to the ground rod to create a large walking area around the pole-handling area that will be at equal potential with the pole.