BSEE: arc flash incident – is the wire still live?

Contract electricians on an offshore platform were installing a three-conductor cable from a transformer to a motor control centre cabinet. The job required coordination between crew members who could not see one another, in different locations. During the first attempt, the team found the cable was too short. They withdrew it, stripped more insulation, and prepared to try again. On the second attempt, the electrician below the motor control centre pushed the cable into the penetration before making contact with the receiving team inside the energized cabinet. The cable end was routed behind a protective barrier near a live bus bar. An electrician inside the cabinet tried to reposition the cable using non-insulated pliers. That action caused an arc flash between the exposed ground wire and the energized bus bar. The electrician received a minor thermal burn and there was charring and damage to an electrical panel. 

Investigation found that the primary causes of the incident were a gap in procedures, and a failure of communication. The Job Safety and Environmental Analysis (JSEA) did not recognize, or control energized electrical hazards. It did not call for electrically rated personal protective equipment (PPE) or insulated tools. Work proceeded on energized equipment without effective, documented communication between the separated work locations.

• The JSEA described routing the cable into the panel but did not identify arc flash hazards, required PPE, or the need for insulated hand tools.
• Crew below pushed the cable before those inside the cabinet were ready to receive it — there was no closed loop communication  - “ready/clear” confirmation or reliable radio backup.
• The electrician inside the cabinet was not wearing arc-rated PPE appropriate to the task and used non-insulated pliers; the tool in use was not electrically rated for exposure to energized conductors.
• The cable was pushed too far into the penetration and migrated behind the protective barrier, bringing exposed conductor(s) into proximity with the live bus bar.
• There was limited visibility/line-of-sight between operators, premature action by the cable-puller, and insufficient situational awareness during cable manipulation.