During an electrical short circuit with an arc flash, a single copper conductor can violently explode and project a large quantity of gaseous debris and molten metal. Copper abruptly transitions from a solid to a gaseous state and expands to approximately 67,000 times its original volume. Projectiles can reach speeds of 1,100 km/h.
An electrical arc flash can reach extreme temperatures, exceeding 20,000°C. American studies have shown that the greatest danger during an electrical incident is related to burns (62% of accidents) rather than electric shock (38%).
Remember that electricity poses a risk to the life and physical integrity of workers. In the United States, every year there are approximately 30,000 non-fatal electrical shocks (electrical injuries) and 1,000 fatal electrical shocks (electrocutions), more than half of which occur during work performed on systems with voltages under 600 V.
The Corporation of Master Electricians of Québec, ASP Construction, and the CNESST have developed summary guides of recommended practices for working on energized electrical systems. These guides include the applicable standards and regulations, as well as tables and methods for selecting appropriate personal protective equipment (PPE) for each task.