Date of incident: January 2021
Notice of incident number: 2021184480001
Employer: Electrical company

Incident summary
At a multiple-tenant commercial building, two electricians were working inside an electrical room. One worker was behind a main distribution centre (MDC), out of sight of the second worker. As the worker behind the MDC started to install a circuit breaker, an arc flash occurred. The worker’s clothing caught fire and he sustained serious injuries.

Investigation conclusions

Cause

• Work performed on energized equipment caused arc flash. When the worker was performing work on the energized MDC, it is likely that he created a bridge between an energized bus bar and the grounded frame of the MDC, which inadvertently caused an arc flash.

Contributing factors

• Lockout procedures not used. The work plan was to de-energize the equipment with a power shutdown. The worker did not lock out the MDC before performing work tasks, nor did he wait until the scheduled power shutdown. As a result, the MDC was energized when he started working on the equipment.

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