August 13, 2008—Engineering students at Johns Hopkins University have invented a tool that would allow utility workers to disconnect power lines from residential transformers at a safe distance, beyond the range of dangerous electrical arcs.
Their prototype, built at the request of a local utility company, consists of a lightweight aluminum frame that uses rope and a lever-and-pulley system to enable the worker to detach a transformer’s power connector, known as a load break elbow. This operation sometimes triggers an explosive arc that can cause serious skin burns and eye injuries. Such arcs can travels as far as 8 feet from the transformer, but the students’ device would enable workers to disconnect the line from 10 to 12 feet away.
“We’re very pleased with the outcome of this project,” said Bruce R. Hirsch, a Baltimore Gas & Electric Co. representative who worked with the students. “What they’ve given us is a good start. It’s a very simple design, and they’ve suggested some further refinements. This device was made to enhance the safety of our people, and that’s BGE’s top priority.”
Currently, because of the risk of an electrical arc, such workers must wear safety goggles, flame retardant clothing, protective gloves and a hard hat, and must use an 8-foot- long “hot stick” to disconnect lines that typically carry 7,600 volts. BGE asked the students to devise a system that would allow the workers to remove such lines from 10 to 12 feet away, beyond the reach of an explosive arc.
For more information, see the Johns Hopkins Web site.
