Our company recently completed a 2-year arc flash hazard analysis for a large steel-making customer. There was a lot of push-back from the people who had been working on this equipment for years and did not believe certain areas of their plant could be Dangerous (above 40 cal/cm2).

One of our recommendations was to lower all of the breaker/relay settings in a portion of the plant that was no longer in use except for a few sump pumps. About a month after lowering these settings, a project to remove unused electrical gear from this area was started. An electrician and a team of laborers were involved. The electrician locked and tagged out the main molded case breaker mounted on an unused slate board. His laborer then climbed a step-ladder to get near the relays hew was about to remove. As climbed the ladder, he held his channel-locks in his left hand and for some unknown reason, propped himself up on the primary side of the molded case breaker with his channel-locks. What could have been a class 4 incident or fatality was averted by the very settings reduced a month earlier. All the laborer suffered in this case was a minor hand burn and a good scare.

After the steel company sheepishly related this story to us, we received a whole lot less push-back about other areas. Sometimes as engineers we get lost in the day-to-day numbers of settings and incident energies. You never know when a small bullet point on a report could save a life.

Good story, thanks for sharing.