Abstract: Two employees, an electrician and a helper, were repairing a damaged transformer and refusing and cleaning a Penn switch box (Model No. IS-S, Serial No. 13- 229-K) to restore power to a transformer manufacturing plant. The box had a Kirk interlock on the outside access door and enclosed a Kearney Iso Quencher gang switch. The electrician was standing directly in front of the open switch box door. He bent down and reached into the box to clean the inside contacts. He was electrocuted when his hand contacted the energized center contact of the three-phase switch. There was a malfunction in the Kearney switch, which was a problem known to the employer and other employees. The electrician had not been wearing his rubber insulating gloves and had not tested the circuit to ensure that it was deenergized before reaching into the box.