Abstract: At 12:45 p.m. on July 29, 2019, an employee was preparing to remove an electrical lead from a bushing on a portable substation. The employer had added a maintenance breaker which allowed maintenance personnel to supply power to a motor that moved a tap changer. The maintenance breaker allowed an extension cord, used to maintain batteries and supply power to a heater, to back-feed electricity through the transformers and up to the bushing that the employee was touching. The maintenance breaker was not operated in a manner to control the energy to the equipment. The employee incurred an electrical shock and burns to his back and hands which required hospitalization.