An apprentice was making connections inside a junction box for a 277v lighting circuit. The journeyman electrician that he was working with was also making connections on the same circuits, on the other side of the elevator. The apprentice began work on the box assuming that all circuits inside the box were de-energized because it was “downstream” of the junction box that was the home run back to the panel, the panel that the journeyman electrician was working on. He did not verify any of the wires with a voltmeter or proximity tester prior to proceeding with stripping insulation from the wires and connecting them utilizing wire nuts. One of the wires that Apprentice was stripping was energized and shocked him when he cut into the insulation. A witness was working ~20’ away from the apprentice and heard the apprentice get shocked. He approached the apprentice and confirmed that he was okay, secured the hot circuit that had been cut, and notified the company foreman. After some investigation it was determined that there was wires for two other circuits that had been incorrectly pulled into the junction box and not capped off. These circuits had been energized previously when all light fixtures connected to these circuits were wired and the additional wires that were pulled into the junction box had not yet been identified.
Factors to consider at your site or on your project include, but are not limited to, the following:
- If tasks require the craftsmen to check for unknown hazards prior work, ensure that the craftsmen are provided with complete procedure or checklists to increase memory and remove assumptions.
- Provide a project/shift logbook for each production crew so that various issues concerning the project can be communicated as needed between work crews.
- Consider how to include the project coordinators, craftsmen and painters in the discussion to protect wiring from paint.