While working on a scheduled outage a crew was performing maintenance on a UG 3 transformer radial run. The crew had first planned to de-energize the whole radial circuit but changed their minds and decided to keep the first transformer in the run energized. Switching was performed and the isolated cable was grounded. After the work was completed grounds were removed and two journeymen were positioned at the first transformer while the other crew members went to the termination pole to de-energize the line. For unknown reasons and against instructions the journeymen at the transformer removed the bushing dummy cap and plugged the energized cable into transformer. This caused a fuse to blow at the fuse pole. No injuries or damage to equipment occurred but the crew foreman reported it as a near miss because if under different circumstances the linemen did not follow procedures the result could have been catastrophic. The linemen at the transformer admitted that they did not understand the instructions.