What happens when workers fail to de-energize

Electrician testing wiring

Workers taking a short cut to "save time" resulted in one individual suffering third degree burns to the top of one hand as the result of an arc flash.

The incident occurred in the main electrical room of a multi-unit building in Port Coquitlam where two workers were installing sub feed cables into the energized main service equipment. The workers had installed new sub service equipment to provide more electrical capacity to one of the building units. When upgrades and sub service is performed, it is standard practice to de-energize electrical equipment, then make connections and re-energize equipment once the work has been tested. Testing involves visually inspecting terminations and cable connections, metering cables for continuity, and confirming phasing.

Technical Safety BC investigated the incident and discovered that the standard testing, visual inspection, and de-energizing were not done. The workers said they were "in a hurry to complete the work for the customer and turning off the main service was not an option."

“Most individuals doing electrical work know they should not work with energized equipment but many still cut corners to save time," says Electrical Safety Officer Mike Brkich. "The worker was lucky to not have experienced more serious injuries. Incidentally, due to the injury and damage to the electrical connection lugs and enclosure, this job ended up taking much longer than it would have had the workers simply turned off the electricity and tested it properly in the first place."

This incident is an important reminder why the BC Electrical Code requires individuals to not work on electric equipment in an energized state. A Technical Safety BC information bulletin and directive reiterate a BC Electrical Code requirement for work to be done only in a de-energized state -- unless a complete disconnection is not feasible. This is also addressed by WorkSafeBC's Guidelines Part 19 - Working on low voltage electrical equipment.

Learn full details in our incident investigation report.

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