A crew working maintenance on a 12kV UG radial line made phase to ground contact on a transformer case

A journeyman lineman in the process of doing a voltage test was pulling a capacitive test cap on an energized dead break elbow when the elbow became dislodged from the transformer bushing and fell onto the case of the transformer. The phase to ground contact caused a large arc flash and blew a single fuse at the termination pole. The remaining fuse caused a primary back feed which kept the dead break elbow energized and the arc flash sustained. There were no injuries to the crew and an examination of the incident revealed that there were no spring bails installed on the elbow to keep it secured to the transformer bushing.