Arc Flashes Flashback!


Congratulations, you’re almost done with the course!  However, let’s take a few minutes to reflect on the course content before you take the final exam. You will only get 2 chances to pass the final with a score of 80% or higher. 

If you aren’t confident in your knowledge of one of the following subjects, go back to the relevant lesson in the course to give it a review.

  • 80% of electrical injuries and fatalities among “qualified workers” are caused by arc flash (Bureau
    of Labor Statistics).
  • Activities with high potential for exposure to arc flash include, troubleshooting live circuits, opening, or closing circuits and/or grounding circuits.
  • Potential arc flash causes may include uninsulated tool contact with a live conductor, Loose wire connections, Accidental contact with live conductors
  • Temperatures associated with an arc flash can be up to 35,000 Fahrenheit.
  • When working around exposed live conductors insulated tools must be used.
  • An arc blast may produce molten shrapnel, sound waves, and damaging pressure waves.
  • NFPA 70E uses categories based on the incident energy of a circuit.
  • According to NFPA 70E, the flash protection boundary is the approach distance from an exposed live part where a person could receive at least a second-degree burn should if within the boundary when an arc flash occurs.
  • Phenomenon where a flashover of electric current leaves its intended path and travels through the air from can be caused from dust, dropping tools, accidental touching and/or condensation.
  • Three factors determine severity of arc flash injury.