Abstract: A four-person crew was installing conductors and circuit breakers for an electric generator for a new testing station at a client's facility. The crew arrived at about 7:30 AM. The owner of the electrical firm, who was one of the crew members, left to buy a special type of grease for pulling the conductors. While two of the remaining crew members prepared the circuit breakers and brought in tools, the fourth one took a bracket for the circuit breaker and went to install it on the vertical 480-volt busbars. While the busbars remained energized, he used a nut driver and a socket wrench to attach the bracket. As he was doing this, the inside of his right arm apparently contacted the busbar, and he was electrocuted.